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Diffstat (limited to 'src/backend/tcop/postgres.c')
| -rw-r--r-- | src/backend/tcop/postgres.c | 4968 |
1 files changed, 4968 insertions, 0 deletions
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c new file mode 100644 index 0000000..2278d85 --- /dev/null +++ b/src/backend/tcop/postgres.c @@ -0,0 +1,4968 @@ +/*------------------------------------------------------------------------- + * + * postgres.c + * POSTGRES C Backend Interface + * + * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California + * + * + * IDENTIFICATION + * src/backend/tcop/postgres.c + * + * NOTES + * this is the "main" module of the postgres backend and + * hence the main module of the "traffic cop". + * + *------------------------------------------------------------------------- + */ + +#include "postgres.h" + +#include <fcntl.h> +#include <limits.h> +#include <signal.h> +#include <unistd.h> +#include <sys/socket.h> +#ifdef HAVE_SYS_SELECT_H +#include <sys/select.h> +#endif +#ifdef HAVE_SYS_RESOURCE_H +#include <sys/time.h> +#include <sys/resource.h> +#endif + +#ifndef HAVE_GETRUSAGE +#include "rusagestub.h" +#endif + +#include "access/parallel.h" +#include "access/printtup.h" +#include "access/xact.h" +#include "catalog/pg_type.h" +#include "commands/async.h" +#include "commands/prepare.h" +#include "jit/jit.h" +#include "libpq/libpq.h" +#include "libpq/pqformat.h" +#include "libpq/pqsignal.h" +#include "mb/pg_wchar.h" +#include "mb/stringinfo_mb.h" +#include "miscadmin.h" +#include "nodes/print.h" +#include "optimizer/optimizer.h" +#include "parser/analyze.h" +#include "parser/parser.h" +#include "pg_getopt.h" +#include "pg_trace.h" +#include "pgstat.h" +#include "postmaster/autovacuum.h" +#include "postmaster/interrupt.h" +#include "postmaster/postmaster.h" +#include "replication/logicallauncher.h" +#include "replication/logicalworker.h" +#include "replication/slot.h" +#include "replication/walsender.h" +#include "rewrite/rewriteHandler.h" +#include "storage/bufmgr.h" +#include "storage/ipc.h" +#include "storage/pmsignal.h" +#include "storage/proc.h" +#include "storage/procsignal.h" +#include "storage/sinval.h" +#include "tcop/fastpath.h" +#include "tcop/pquery.h" +#include "tcop/tcopprot.h" +#include "tcop/utility.h" +#include "utils/lsyscache.h" +#include "utils/memutils.h" +#include "utils/ps_status.h" +#include "utils/snapmgr.h" +#include "utils/timeout.h" +#include "utils/timestamp.h" + +/* ---------------- + * global variables + * ---------------- + */ +const char *debug_query_string; /* client-supplied query string */ + +/* Note: whereToSendOutput is initialized for the bootstrap/standalone case */ +CommandDest whereToSendOutput = DestDebug; + +/* flag for logging end of session */ +bool Log_disconnections = false; + +int log_statement = LOGSTMT_NONE; + +/* GUC variable for maximum stack depth (measured in kilobytes) */ +int max_stack_depth = 100; + +/* wait N seconds to allow attach from a debugger */ +int PostAuthDelay = 0; + +/* Time between checks that the client is still connected. */ +int client_connection_check_interval = 0; + +/* ---------------- + * private typedefs etc + * ---------------- + */ + +/* type of argument for bind_param_error_callback */ +typedef struct BindParamCbData +{ + const char *portalName; + int paramno; /* zero-based param number, or -1 initially */ + const char *paramval; /* textual input string, if available */ +} BindParamCbData; + +/* ---------------- + * private variables + * ---------------- + */ + +/* max_stack_depth converted to bytes for speed of checking */ +static long max_stack_depth_bytes = 100 * 1024L; + +/* + * Stack base pointer -- initialized by PostmasterMain and inherited by + * subprocesses. This is not static because old versions of PL/Java modify + * it directly. Newer versions use set_stack_base(), but we want to stay + * binary-compatible for the time being. + */ +char *stack_base_ptr = NULL; + +/* + * On IA64 we also have to remember the register stack base. + */ +#if defined(__ia64__) || defined(__ia64) +char *register_stack_base_ptr = NULL; +#endif + +/* + * Flag to keep track of whether we have started a transaction. + * For extended query protocol this has to be remembered across messages. + */ +static bool xact_started = false; + +/* + * Flag to indicate that we are doing the outer loop's read-from-client, + * as opposed to any random read from client that might happen within + * commands like COPY FROM STDIN. + */ +static bool DoingCommandRead = false; + +/* + * Flags to implement skip-till-Sync-after-error behavior for messages of + * the extended query protocol. + */ +static bool doing_extended_query_message = false; +static bool ignore_till_sync = false; + +/* + * If an unnamed prepared statement exists, it's stored here. + * We keep it separate from the hashtable kept by commands/prepare.c + * in order to reduce overhead for short-lived queries. + */ +static CachedPlanSource *unnamed_stmt_psrc = NULL; + +/* assorted command-line switches */ +static const char *userDoption = NULL; /* -D switch */ +static bool EchoQuery = false; /* -E switch */ +static bool UseSemiNewlineNewline = false; /* -j switch */ + +/* whether or not, and why, we were canceled by conflict with recovery */ +static bool RecoveryConflictPending = false; +static bool RecoveryConflictRetryable = true; +static ProcSignalReason RecoveryConflictReason; + +/* reused buffer to pass to SendRowDescriptionMessage() */ +static MemoryContext row_description_context = NULL; +static StringInfoData row_description_buf; + +/* ---------------------------------------------------------------- + * decls for routines only used in this file + * ---------------------------------------------------------------- + */ +static int InteractiveBackend(StringInfo inBuf); +static int interactive_getc(void); +static int SocketBackend(StringInfo inBuf); +static int ReadCommand(StringInfo inBuf); +static void forbidden_in_wal_sender(char firstchar); +static bool check_log_statement(List *stmt_list); +static int errdetail_execute(List *raw_parsetree_list); +static int errdetail_params(ParamListInfo params); +static int errdetail_abort(void); +static int errdetail_recovery_conflict(void); +static void bind_param_error_callback(void *arg); +static void start_xact_command(void); +static void finish_xact_command(void); +static bool IsTransactionExitStmt(Node *parsetree); +static bool IsTransactionExitStmtList(List *pstmts); +static bool IsTransactionStmtList(List *pstmts); +static void drop_unnamed_stmt(void); +static void log_disconnections(int code, Datum arg); +static void enable_statement_timeout(void); +static void disable_statement_timeout(void); + + +/* ---------------------------------------------------------------- + * routines to obtain user input + * ---------------------------------------------------------------- + */ + +/* ---------------- + * InteractiveBackend() is called for user interactive connections + * + * the string entered by the user is placed in its parameter inBuf, + * and we act like a Q message was received. + * + * EOF is returned if end-of-file input is seen; time to shut down. + * ---------------- + */ + +static int +InteractiveBackend(StringInfo inBuf) +{ + int c; /* character read from getc() */ + + /* + * display a prompt and obtain input from the user + */ + printf("backend> "); + fflush(stdout); + + resetStringInfo(inBuf); + + /* + * Read characters until EOF or the appropriate delimiter is seen. + */ + while ((c = interactive_getc()) != EOF) + { + if (c == '\n') + { + if (UseSemiNewlineNewline) + { + /* + * In -j mode, semicolon followed by two newlines ends the + * command; otherwise treat newline as regular character. + */ + if (inBuf->len > 1 && + inBuf->data[inBuf->len - 1] == '\n' && + inBuf->data[inBuf->len - 2] == ';') + { + /* might as well drop the second newline */ + break; + } + } + else + { + /* + * In plain mode, newline ends the command unless preceded by + * backslash. + */ + if (inBuf->len > 0 && + inBuf->data[inBuf->len - 1] == '\\') + { + /* discard backslash from inBuf */ + inBuf->data[--inBuf->len] = '\0'; + /* discard newline too */ + continue; + } + else + { + /* keep the newline character, but end the command */ + appendStringInfoChar(inBuf, '\n'); + break; + } + } + } + + /* Not newline, or newline treated as regular character */ + appendStringInfoChar(inBuf, (char) c); + } + + /* No input before EOF signal means time to quit. */ + if (c == EOF && inBuf->len == 0) + return EOF; + + /* + * otherwise we have a user query so process it. + */ + + /* Add '\0' to make it look the same as message case. */ + appendStringInfoChar(inBuf, (char) '\0'); + + /* + * if the query echo flag was given, print the query.. + */ + if (EchoQuery) + printf("statement: %s\n", inBuf->data); + fflush(stdout); + + return 'Q'; +} + +/* + * interactive_getc -- collect one character from stdin + * + * Even though we are not reading from a "client" process, we still want to + * respond to signals, particularly SIGTERM/SIGQUIT. + */ +static int +interactive_getc(void) +{ + int c; + + /* + * This will not process catchup interrupts or notifications while + * reading. But those can't really be relevant for a standalone backend + * anyway. To properly handle SIGTERM there's a hack in die() that + * directly processes interrupts at this stage... + */ + CHECK_FOR_INTERRUPTS(); + + c = getc(stdin); + + ProcessClientReadInterrupt(false); + + return c; +} + +/* ---------------- + * SocketBackend() Is called for frontend-backend connections + * + * Returns the message type code, and loads message body data into inBuf. + * + * EOF is returned if the connection is lost. + * ---------------- + */ +static int +SocketBackend(StringInfo inBuf) +{ + int qtype; + int maxmsglen; + + /* + * Get message type code from the frontend. + */ + HOLD_CANCEL_INTERRUPTS(); + pq_startmsgread(); + qtype = pq_getbyte(); + + if (qtype == EOF) /* frontend disconnected */ + { + if (IsTransactionState()) + ereport(COMMERROR, + (errcode(ERRCODE_CONNECTION_FAILURE), + errmsg("unexpected EOF on client connection with an open transaction"))); + else + { + /* + * Can't send DEBUG log messages to client at this point. Since + * we're disconnecting right away, we don't need to restore + * whereToSendOutput. + */ + whereToSendOutput = DestNone; + ereport(DEBUG1, + (errcode(ERRCODE_CONNECTION_DOES_NOT_EXIST), + errmsg_internal("unexpected EOF on client connection"))); + } + return qtype; + } + + /* + * Validate message type code before trying to read body; if we have lost + * sync, better to say "command unknown" than to run out of memory because + * we used garbage as a length word. We can also select a type-dependent + * limit on what a sane length word could be. (The limit could be chosen + * more granularly, but it's not clear it's worth fussing over.) + * + * This also gives us a place to set the doing_extended_query_message flag + * as soon as possible. + */ + switch (qtype) + { + case 'Q': /* simple query */ + maxmsglen = PQ_LARGE_MESSAGE_LIMIT; + doing_extended_query_message = false; + break; + + case 'F': /* fastpath function call */ + maxmsglen = PQ_LARGE_MESSAGE_LIMIT; + doing_extended_query_message = false; + break; + + case 'X': /* terminate */ + maxmsglen = PQ_SMALL_MESSAGE_LIMIT; + doing_extended_query_message = false; + ignore_till_sync = false; + break; + + case 'B': /* bind */ + case 'P': /* parse */ + maxmsglen = PQ_LARGE_MESSAGE_LIMIT; + doing_extended_query_message = true; + break; + + case 'C': /* close */ + case 'D': /* describe */ + case 'E': /* execute */ + case 'H': /* flush */ + maxmsglen = PQ_SMALL_MESSAGE_LIMIT; + doing_extended_query_message = true; + break; + + case 'S': /* sync */ + maxmsglen = PQ_SMALL_MESSAGE_LIMIT; + /* stop any active skip-till-Sync */ + ignore_till_sync = false; + /* mark not-extended, so that a new error doesn't begin skip */ + doing_extended_query_message = false; + break; + + case 'd': /* copy data */ + maxmsglen = PQ_LARGE_MESSAGE_LIMIT; + doing_extended_query_message = false; + break; + + case 'c': /* copy done */ + case 'f': /* copy fail */ + maxmsglen = PQ_SMALL_MESSAGE_LIMIT; + doing_extended_query_message = false; + break; + + default: + + /* + * Otherwise we got garbage from the frontend. We treat this as + * fatal because we have probably lost message boundary sync, and + * there's no good way to recover. + */ + ereport(FATAL, + (errcode(ERRCODE_PROTOCOL_VIOLATION), + errmsg("invalid frontend message type %d", qtype))); + maxmsglen = 0; /* keep compiler quiet */ + break; + } + + /* + * In protocol version 3, all frontend messages have a length word next + * after the type code; we can read the message contents independently of + * the type. + */ + if (pq_getmessage(inBuf, maxmsglen)) + return EOF; /* suitable message already logged */ + RESUME_CANCEL_INTERRUPTS(); + + return qtype; +} + +/* ---------------- + * ReadCommand reads a command from either the frontend or + * standard input, places it in inBuf, and returns the + * message type code (first byte of the message). + * EOF is returned if end of file. + * ---------------- + */ +static int +ReadCommand(StringInfo inBuf) +{ + int result; + + if (whereToSendOutput == DestRemote) + result = SocketBackend(inBuf); + else + result = InteractiveBackend(inBuf); + return result; +} + +/* + * ProcessClientReadInterrupt() - Process interrupts specific to client reads + * + * This is called just before and after low-level reads. + * 'blocked' is true if no data was available to read and we plan to retry, + * false if about to read or done reading. + * + * Must preserve errno! + */ +void +ProcessClientReadInterrupt(bool blocked) +{ + int save_errno = errno; + + if (DoingCommandRead) + { + /* Check for general interrupts that arrived before/while reading */ + CHECK_FOR_INTERRUPTS(); + + /* Process sinval catchup interrupts, if any */ + if (catchupInterruptPending) + ProcessCatchupInterrupt(); + + /* Process notify interrupts, if any */ + if (notifyInterruptPending) + ProcessNotifyInterrupt(true); + } + else if (ProcDiePending) + { + /* + * We're dying. If there is no data available to read, then it's safe + * (and sane) to handle that now. If we haven't tried to read yet, + * make sure the process latch is set, so that if there is no data + * then we'll come back here and die. If we're done reading, also + * make sure the process latch is set, as we might've undesirably + * cleared it while reading. + */ + if (blocked) + CHECK_FOR_INTERRUPTS(); + else + SetLatch(MyLatch); + } + + errno = save_errno; +} + +/* + * ProcessClientWriteInterrupt() - Process interrupts specific to client writes + * + * This is called just before and after low-level writes. + * 'blocked' is true if no data could be written and we plan to retry, + * false if about to write or done writing. + * + * Must preserve errno! + */ +void +ProcessClientWriteInterrupt(bool blocked) +{ + int save_errno = errno; + + if (ProcDiePending) + { + /* + * We're dying. If it's not possible to write, then we should handle + * that immediately, else a stuck client could indefinitely delay our + * response to the signal. If we haven't tried to write yet, make + * sure the process latch is set, so that if the write would block + * then we'll come back here and die. If we're done writing, also + * make sure the process latch is set, as we might've undesirably + * cleared it while writing. + */ + if (blocked) + { + /* + * Don't mess with whereToSendOutput if ProcessInterrupts wouldn't + * service ProcDiePending. + */ + if (InterruptHoldoffCount == 0 && CritSectionCount == 0) + { + /* + * We don't want to send the client the error message, as a) + * that would possibly block again, and b) it would likely + * lead to loss of protocol sync because we may have already + * sent a partial protocol message. + */ + if (whereToSendOutput == DestRemote) + whereToSendOutput = DestNone; + + CHECK_FOR_INTERRUPTS(); + } + } + else + SetLatch(MyLatch); + } + + errno = save_errno; +} + +/* + * Do raw parsing (only). + * + * A list of parsetrees (RawStmt nodes) is returned, since there might be + * multiple commands in the given string. + * + * NOTE: for interactive queries, it is important to keep this routine + * separate from the analysis & rewrite stages. Analysis and rewriting + * cannot be done in an aborted transaction, since they require access to + * database tables. So, we rely on the raw parser to determine whether + * we've seen a COMMIT or ABORT command; when we are in abort state, other + * commands are not processed any further than the raw parse stage. + */ +List * +pg_parse_query(const char *query_string) +{ + List *raw_parsetree_list; + + TRACE_POSTGRESQL_QUERY_PARSE_START(query_string); + + if (log_parser_stats) + ResetUsage(); + + raw_parsetree_list = raw_parser(query_string, RAW_PARSE_DEFAULT); + + if (log_parser_stats) + ShowUsage("PARSER STATISTICS"); + +#ifdef COPY_PARSE_PLAN_TREES + /* Optional debugging check: pass raw parsetrees through copyObject() */ + { + List *new_list = copyObject(raw_parsetree_list); + + /* This checks both copyObject() and the equal() routines... */ + if (!equal(new_list, raw_parsetree_list)) + elog(WARNING, "copyObject() failed to produce an equal raw parse tree"); + else + raw_parsetree_list = new_list; + } +#endif + + /* + * Currently, outfuncs/readfuncs support is missing for many raw parse + * tree nodes, so we don't try to implement WRITE_READ_PARSE_PLAN_TREES + * here. + */ + + TRACE_POSTGRESQL_QUERY_PARSE_DONE(query_string); + + return raw_parsetree_list; +} + +/* + * Given a raw parsetree (gram.y output), and optionally information about + * types of parameter symbols ($n), perform parse analysis and rule rewriting. + * + * A list of Query nodes is returned, since either the analyzer or the + * rewriter might expand one query to several. + * + * NOTE: for reasons mentioned above, this must be separate from raw parsing. + */ +List * +pg_analyze_and_rewrite(RawStmt *parsetree, const char *query_string, + Oid *paramTypes, int numParams, + QueryEnvironment *queryEnv) +{ + Query *query; + List *querytree_list; + + TRACE_POSTGRESQL_QUERY_REWRITE_START(query_string); + + /* + * (1) Perform parse analysis. + */ + if (log_parser_stats) + ResetUsage(); + + query = parse_analyze(parsetree, query_string, paramTypes, numParams, + queryEnv); + + if (log_parser_stats) + ShowUsage("PARSE ANALYSIS STATISTICS"); + + /* + * (2) Rewrite the queries, as necessary + */ + querytree_list = pg_rewrite_query(query); + + TRACE_POSTGRESQL_QUERY_REWRITE_DONE(query_string); + + return querytree_list; +} + +/* + * Do parse analysis and rewriting. This is the same as pg_analyze_and_rewrite + * except that external-parameter resolution is determined by parser callback + * hooks instead of a fixed list of parameter datatypes. + */ +List * +pg_analyze_and_rewrite_params(RawStmt *parsetree, + const char *query_string, + ParserSetupHook parserSetup, + void *parserSetupArg, + QueryEnvironment *queryEnv) +{ + ParseState *pstate; + Query *query; + List *querytree_list; + JumbleState *jstate = NULL; + + Assert(query_string != NULL); /* required as of 8.4 */ + + TRACE_POSTGRESQL_QUERY_REWRITE_START(query_string); + + /* + * (1) Perform parse analysis. + */ + if (log_parser_stats) + ResetUsage(); + + pstate = make_parsestate(NULL); + pstate->p_sourcetext = query_string; + pstate->p_queryEnv = queryEnv; + (*parserSetup) (pstate, parserSetupArg); + + query = transformTopLevelStmt(pstate, parsetree); + + if (IsQueryIdEnabled()) + jstate = JumbleQuery(query, query_string); + + if (post_parse_analyze_hook) + (*post_parse_analyze_hook) (pstate, query, jstate); + + free_parsestate(pstate); + + pgstat_report_query_id(query->queryId, false); + + if (log_parser_stats) + ShowUsage("PARSE ANALYSIS STATISTICS"); + + /* + * (2) Rewrite the queries, as necessary + */ + querytree_list = pg_rewrite_query(query); + + TRACE_POSTGRESQL_QUERY_REWRITE_DONE(query_string); + + return querytree_list; +} + +/* + * Perform rewriting of a query produced by parse analysis. + * + * Note: query must just have come from the parser, because we do not do + * AcquireRewriteLocks() on it. + */ +List * +pg_rewrite_query(Query *query) +{ + List *querytree_list; + + if (Debug_print_parse) + elog_node_display(LOG, "parse tree", query, + Debug_pretty_print); + + if (log_parser_stats) + ResetUsage(); + + if (query->commandType == CMD_UTILITY) + { + /* don't rewrite utilities, just dump 'em into result list */ + querytree_list = list_make1(query); + } + else + { + /* rewrite regular queries */ + querytree_list = QueryRewrite(query); + } + + if (log_parser_stats) + ShowUsage("REWRITER STATISTICS"); + +#ifdef COPY_PARSE_PLAN_TREES + /* Optional debugging check: pass querytree through copyObject() */ + { + List *new_list; + + new_list = copyObject(querytree_list); + /* This checks both copyObject() and the equal() routines... */ + if (!equal(new_list, querytree_list)) + elog(WARNING, "copyObject() failed to produce equal parse tree"); + else + querytree_list = new_list; + } +#endif + +#ifdef WRITE_READ_PARSE_PLAN_TREES + /* Optional debugging check: pass querytree through outfuncs/readfuncs */ + { + List *new_list = NIL; + ListCell *lc; + + /* + * We currently lack outfuncs/readfuncs support for most utility + * statement types, so only attempt to write/read non-utility queries. + */ + foreach(lc, querytree_list) + { + Query *query = castNode(Query, lfirst(lc)); + + if (query->commandType != CMD_UTILITY) + { + char *str = nodeToString(query); + Query *new_query = stringToNodeWithLocations(str); + + /* + * queryId is not saved in stored rules, but we must preserve + * it here to avoid breaking pg_stat_statements. + */ + new_query->queryId = query->queryId; + + new_list = lappend(new_list, new_query); + pfree(str); + } + else + new_list = lappend(new_list, query); + } + + /* This checks both outfuncs/readfuncs and the equal() routines... */ + if (!equal(new_list, querytree_list)) + elog(WARNING, "outfuncs/readfuncs failed to produce equal parse tree"); + else + querytree_list = new_list; + } +#endif + + if (Debug_print_rewritten) + elog_node_display(LOG, "rewritten parse tree", querytree_list, + Debug_pretty_print); + + return querytree_list; +} + + +/* + * Generate a plan for a single already-rewritten query. + * This is a thin wrapper around planner() and takes the same parameters. + */ +PlannedStmt * +pg_plan_query(Query *querytree, const char *query_string, int cursorOptions, + ParamListInfo boundParams) +{ + PlannedStmt *plan; + + /* Utility commands have no plans. */ + if (querytree->commandType == CMD_UTILITY) + return NULL; + + /* Planner must have a snapshot in case it calls user-defined functions. */ + Assert(ActiveSnapshotSet()); + + TRACE_POSTGRESQL_QUERY_PLAN_START(); + + if (log_planner_stats) + ResetUsage(); + + /* call the optimizer */ + plan = planner(querytree, query_string, cursorOptions, boundParams); + + if (log_planner_stats) + ShowUsage("PLANNER STATISTICS"); + +#ifdef COPY_PARSE_PLAN_TREES + /* Optional debugging check: pass plan tree through copyObject() */ + { + PlannedStmt *new_plan = copyObject(plan); + + /* + * equal() currently does not have routines to compare Plan nodes, so + * don't try to test equality here. Perhaps fix someday? + */ +#ifdef NOT_USED + /* This checks both copyObject() and the equal() routines... */ + if (!equal(new_plan, plan)) + elog(WARNING, "copyObject() failed to produce an equal plan tree"); + else +#endif + plan = new_plan; + } +#endif + +#ifdef WRITE_READ_PARSE_PLAN_TREES + /* Optional debugging check: pass plan tree through outfuncs/readfuncs */ + { + char *str; + PlannedStmt *new_plan; + + str = nodeToString(plan); + new_plan = stringToNodeWithLocations(str); + pfree(str); + + /* + * equal() currently does not have routines to compare Plan nodes, so + * don't try to test equality here. Perhaps fix someday? + */ +#ifdef NOT_USED + /* This checks both outfuncs/readfuncs and the equal() routines... */ + if (!equal(new_plan, plan)) + elog(WARNING, "outfuncs/readfuncs failed to produce an equal plan tree"); + else +#endif + plan = new_plan; + } +#endif + + /* + * Print plan if debugging. + */ + if (Debug_print_plan) + elog_node_display(LOG, "plan", plan, Debug_pretty_print); + + TRACE_POSTGRESQL_QUERY_PLAN_DONE(); + + return plan; +} + +/* + * Generate plans for a list of already-rewritten queries. + * + * For normal optimizable statements, invoke the planner. For utility + * statements, just make a wrapper PlannedStmt node. + * + * The result is a list of PlannedStmt nodes. + */ +List * +pg_plan_queries(List *querytrees, const char *query_string, int cursorOptions, + ParamListInfo boundParams) +{ + List *stmt_list = NIL; + ListCell *query_list; + + foreach(query_list, querytrees) + { + Query *query = lfirst_node(Query, query_list); + PlannedStmt *stmt; + + if (query->commandType == CMD_UTILITY) + { + /* Utility commands require no planning. */ + stmt = makeNode(PlannedStmt); + stmt->commandType = CMD_UTILITY; + stmt->canSetTag = query->canSetTag; + stmt->utilityStmt = query->utilityStmt; + stmt->stmt_location = query->stmt_location; + stmt->stmt_len = query->stmt_len; + stmt->queryId = query->queryId; + } + else + { + stmt = pg_plan_query(query, query_string, cursorOptions, + boundParams); + } + + stmt_list = lappend(stmt_list, stmt); + } + + return stmt_list; +} + + +/* + * exec_simple_query + * + * Execute a "simple Query" protocol message. + */ +static void +exec_simple_query(const char *query_string) +{ + CommandDest dest = whereToSendOutput; + MemoryContext oldcontext; + List *parsetree_list; + ListCell *parsetree_item; + bool save_log_statement_stats = log_statement_stats; + bool was_logged = false; + bool use_implicit_block; + char msec_str[32]; + + /* + * Report query to various monitoring facilities. + */ + debug_query_string = query_string; + + pgstat_report_activity(STATE_RUNNING, query_string); + + TRACE_POSTGRESQL_QUERY_START(query_string); + + /* + * We use save_log_statement_stats so ShowUsage doesn't report incorrect + * results because ResetUsage wasn't called. + */ + if (save_log_statement_stats) + ResetUsage(); + + /* + * Start up a transaction command. All queries generated by the + * query_string will be in this same command block, *unless* we find a + * BEGIN/COMMIT/ABORT statement; we have to force a new xact command after + * one of those, else bad things will happen in xact.c. (Note that this + * will normally change current memory context.) + */ + start_xact_command(); + + /* + * Zap any pre-existing unnamed statement. (While not strictly necessary, + * it seems best to define simple-Query mode as if it used the unnamed + * statement and portal; this ensures we recover any storage used by prior + * unnamed operations.) + */ + drop_unnamed_stmt(); + + /* + * Switch to appropriate context for constructing parsetrees. + */ + oldcontext = MemoryContextSwitchTo(MessageContext); + + /* + * Do basic parsing of the query or queries (this should be safe even if + * we are in aborted transaction state!) + */ + parsetree_list = pg_parse_query(query_string); + + /* Log immediately if dictated by log_statement */ + if (check_log_statement(parsetree_list)) + { + ereport(LOG, + (errmsg("statement: %s", query_string), + errhidestmt(true), + errdetail_execute(parsetree_list))); + was_logged = true; + } + + /* + * Switch back to transaction context to enter the loop. + */ + MemoryContextSwitchTo(oldcontext); + + /* + * For historical reasons, if multiple SQL statements are given in a + * single "simple Query" message, we execute them as a single transaction, + * unless explicit transaction control commands are included to make + * portions of the list be separate transactions. To represent this + * behavior properly in the transaction machinery, we use an "implicit" + * transaction block. + */ + use_implicit_block = (list_length(parsetree_list) > 1); + + /* + * Run through the raw parsetree(s) and process each one. + */ + foreach(parsetree_item, parsetree_list) + { + RawStmt *parsetree = lfirst_node(RawStmt, parsetree_item); + bool snapshot_set = false; + CommandTag commandTag; + QueryCompletion qc; + MemoryContext per_parsetree_context = NULL; + List *querytree_list, + *plantree_list; + Portal portal; + DestReceiver *receiver; + int16 format; + + pgstat_report_query_id(0, true); + + /* + * Get the command name for use in status display (it also becomes the + * default completion tag, down inside PortalRun). Set ps_status and + * do any special start-of-SQL-command processing needed by the + * destination. + */ + commandTag = CreateCommandTag(parsetree->stmt); + + set_ps_display(GetCommandTagName(commandTag)); + + BeginCommand(commandTag, dest); + + /* + * If we are in an aborted transaction, reject all commands except + * COMMIT/ABORT. It is important that this test occur before we try + * to do parse analysis, rewrite, or planning, since all those phases + * try to do database accesses, which may fail in abort state. (It + * might be safe to allow some additional utility commands in this + * state, but not many...) + */ + if (IsAbortedTransactionBlockState() && + !IsTransactionExitStmt(parsetree->stmt)) + ereport(ERROR, + (errcode(ERRCODE_IN_FAILED_SQL_TRANSACTION), + errmsg("current transaction is aborted, " + "commands ignored until end of transaction block"), + errdetail_abort())); + + /* Make sure we are in a transaction command */ + start_xact_command(); + + /* + * If using an implicit transaction block, and we're not already in a + * transaction block, start an implicit block to force this statement + * to be grouped together with any following ones. (We must do this + * each time through the loop; otherwise, a COMMIT/ROLLBACK in the + * list would cause later statements to not be grouped.) + */ + if (use_implicit_block) + BeginImplicitTransactionBlock(); + + /* If we got a cancel signal in parsing or prior command, quit */ + CHECK_FOR_INTERRUPTS(); + + /* + * Set up a snapshot if parse analysis/planning will need one. + */ + if (analyze_requires_snapshot(parsetree)) + { + PushActiveSnapshot(GetTransactionSnapshot()); + snapshot_set = true; + } + + /* + * OK to analyze, rewrite, and plan this query. + * + * Switch to appropriate context for constructing query and plan trees + * (these can't be in the transaction context, as that will get reset + * when the command is COMMIT/ROLLBACK). If we have multiple + * parsetrees, we use a separate context for each one, so that we can + * free that memory before moving on to the next one. But for the + * last (or only) parsetree, just use MessageContext, which will be + * reset shortly after completion anyway. In event of an error, the + * per_parsetree_context will be deleted when MessageContext is reset. + */ + if (lnext(parsetree_list, parsetree_item) != NULL) + { + per_parsetree_context = + AllocSetContextCreate(MessageContext, + "per-parsetree message context", + ALLOCSET_DEFAULT_SIZES); + oldcontext = MemoryContextSwitchTo(per_parsetree_context); + } + else + oldcontext = MemoryContextSwitchTo(MessageContext); + + querytree_list = pg_analyze_and_rewrite(parsetree, query_string, + NULL, 0, NULL); + + plantree_list = pg_plan_queries(querytree_list, query_string, + CURSOR_OPT_PARALLEL_OK, NULL); + + /* + * Done with the snapshot used for parsing/planning. + * + * While it looks promising to reuse the same snapshot for query + * execution (at least for simple protocol), unfortunately it causes + * execution to use a snapshot that has been acquired before locking + * any of the tables mentioned in the query. This creates user- + * visible anomalies, so refrain. Refer to + * https://postgr.es/m/flat/5075D8DF.6050500@fuzzy.cz for details. + */ + if (snapshot_set) + PopActiveSnapshot(); + + /* If we got a cancel signal in analysis or planning, quit */ + CHECK_FOR_INTERRUPTS(); + + /* + * Create unnamed portal to run the query or queries in. If there + * already is one, silently drop it. + */ + portal = CreatePortal("", true, true); + /* Don't display the portal in pg_cursors */ + portal->visible = false; + + /* + * We don't have to copy anything into the portal, because everything + * we are passing here is in MessageContext or the + * per_parsetree_context, and so will outlive the portal anyway. + */ + PortalDefineQuery(portal, + NULL, + query_string, + commandTag, + plantree_list, + NULL); + + /* + * Start the portal. No parameters here. + */ + PortalStart(portal, NULL, 0, InvalidSnapshot); + + /* + * Select the appropriate output format: text unless we are doing a + * FETCH from a binary cursor. (Pretty grotty to have to do this here + * --- but it avoids grottiness in other places. Ah, the joys of + * backward compatibility...) + */ + format = 0; /* TEXT is default */ + if (IsA(parsetree->stmt, FetchStmt)) + { + FetchStmt *stmt = (FetchStmt *) parsetree->stmt; + + if (!stmt->ismove) + { + Portal fportal = GetPortalByName(stmt->portalname); + + if (PortalIsValid(fportal) && + (fportal->cursorOptions & CURSOR_OPT_BINARY)) + format = 1; /* BINARY */ + } + } + PortalSetResultFormat(portal, 1, &format); + + /* + * Now we can create the destination receiver object. + */ + receiver = CreateDestReceiver(dest); + if (dest == DestRemote) + SetRemoteDestReceiverParams(receiver, portal); + + /* + * Switch back to transaction context for execution. + */ + MemoryContextSwitchTo(oldcontext); + + /* + * Run the portal to completion, and then drop it (and the receiver). + */ + (void) PortalRun(portal, + FETCH_ALL, + true, /* always top level */ + true, + receiver, + receiver, + &qc); + + receiver->rDestroy(receiver); + + PortalDrop(portal, false); + + if (lnext(parsetree_list, parsetree_item) == NULL) + { + /* + * If this is the last parsetree of the query string, close down + * transaction statement before reporting command-complete. This + * is so that any end-of-transaction errors are reported before + * the command-complete message is issued, to avoid confusing + * clients who will expect either a command-complete message or an + * error, not one and then the other. Also, if we're using an + * implicit transaction block, we must close that out first. + */ + if (use_implicit_block) + EndImplicitTransactionBlock(); + finish_xact_command(); + } + else if (IsA(parsetree->stmt, TransactionStmt)) + { + /* + * If this was a transaction control statement, commit it. We will + * start a new xact command for the next command. + */ + finish_xact_command(); + } + else + { + /* + * We had better not see XACT_FLAGS_NEEDIMMEDIATECOMMIT set if + * we're not calling finish_xact_command(). (The implicit + * transaction block should have prevented it from getting set.) + */ + Assert(!(MyXactFlags & XACT_FLAGS_NEEDIMMEDIATECOMMIT)); + + /* + * We need a CommandCounterIncrement after every query, except + * those that start or end a transaction block. + */ + CommandCounterIncrement(); + + /* + * Disable statement timeout between queries of a multi-query + * string, so that the timeout applies separately to each query. + * (Our next loop iteration will start a fresh timeout.) + */ + disable_statement_timeout(); + } + + /* + * Tell client that we're done with this query. Note we emit exactly + * one EndCommand report for each raw parsetree, thus one for each SQL + * command the client sent, regardless of rewriting. (But a command + * aborted by error will not send an EndCommand report at all.) + */ + EndCommand(&qc, dest, false); + + /* Now we may drop the per-parsetree context, if one was created. */ + if (per_parsetree_context) + MemoryContextDelete(per_parsetree_context); + } /* end loop over parsetrees */ + + /* + * Close down transaction statement, if one is open. (This will only do + * something if the parsetree list was empty; otherwise the last loop + * iteration already did it.) + */ + finish_xact_command(); + + /* + * If there were no parsetrees, return EmptyQueryResponse message. + */ + if (!parsetree_list) + NullCommand(dest); + + /* + * Emit duration logging if appropriate. + */ + switch (check_log_duration(msec_str, was_logged)) + { + case 1: + ereport(LOG, + (errmsg("duration: %s ms", msec_str), + errhidestmt(true))); + break; + case 2: + ereport(LOG, + (errmsg("duration: %s ms statement: %s", + msec_str, query_string), + errhidestmt(true), + errdetail_execute(parsetree_list))); + break; + } + + if (save_log_statement_stats) + ShowUsage("QUERY STATISTICS"); + + TRACE_POSTGRESQL_QUERY_DONE(query_string); + + debug_query_string = NULL; +} + +/* + * exec_parse_message + * + * Execute a "Parse" protocol message. + */ +static void +exec_parse_message(const char *query_string, /* string to execute */ + const char *stmt_name, /* name for prepared stmt */ + Oid *paramTypes, /* parameter types */ + int numParams) /* number of parameters */ +{ + MemoryContext unnamed_stmt_context = NULL; + MemoryContext oldcontext; + List *parsetree_list; + RawStmt *raw_parse_tree; + List *querytree_list; + CachedPlanSource *psrc; + bool is_named; + bool save_log_statement_stats = log_statement_stats; + char msec_str[32]; + + /* + * Report query to various monitoring facilities. + */ + debug_query_string = query_string; + + pgstat_report_activity(STATE_RUNNING, query_string); + + set_ps_display("PARSE"); + + if (save_log_statement_stats) + ResetUsage(); + + ereport(DEBUG2, + (errmsg_internal("parse %s: %s", + *stmt_name ? stmt_name : "<unnamed>", + query_string))); + + /* + * Start up a transaction command so we can run parse analysis etc. (Note + * that this will normally change current memory context.) Nothing happens + * if we are already in one. This also arms the statement timeout if + * necessary. + */ + start_xact_command(); + + /* + * Switch to appropriate context for constructing parsetrees. + * + * We have two strategies depending on whether the prepared statement is + * named or not. For a named prepared statement, we do parsing in + * MessageContext and copy the finished trees into the prepared + * statement's plancache entry; then the reset of MessageContext releases + * temporary space used by parsing and rewriting. For an unnamed prepared + * statement, we assume the statement isn't going to hang around long, so + * getting rid of temp space quickly is probably not worth the costs of + * copying parse trees. So in this case, we create the plancache entry's + * query_context here, and do all the parsing work therein. + */ + is_named = (stmt_name[0] != '\0'); + if (is_named) + { + /* Named prepared statement --- parse in MessageContext */ + oldcontext = MemoryContextSwitchTo(MessageContext); + } + else + { + /* Unnamed prepared statement --- release any prior unnamed stmt */ + drop_unnamed_stmt(); + /* Create context for parsing */ + unnamed_stmt_context = + AllocSetContextCreate(MessageContext, + "unnamed prepared statement", + ALLOCSET_DEFAULT_SIZES); + oldcontext = MemoryContextSwitchTo(unnamed_stmt_context); + } + + /* + * Do basic parsing of the query or queries (this should be safe even if + * we are in aborted transaction state!) + */ + parsetree_list = pg_parse_query(query_string); + + /* + * We only allow a single user statement in a prepared statement. This is + * mainly to keep the protocol simple --- otherwise we'd need to worry + * about multiple result tupdescs and things like that. + */ + if (list_length(parsetree_list) > 1) + ereport(ERROR, + (errcode(ERRCODE_SYNTAX_ERROR), + errmsg("cannot insert multiple commands into a prepared statement"))); + + if (parsetree_list != NIL) + { + Query *query; + bool snapshot_set = false; + + raw_parse_tree = linitial_node(RawStmt, parsetree_list); + + /* + * If we are in an aborted transaction, reject all commands except + * COMMIT/ROLLBACK. It is important that this test occur before we + * try to do parse analysis, rewrite, or planning, since all those + * phases try to do database accesses, which may fail in abort state. + * (It might be safe to allow some additional utility commands in this + * state, but not many...) + */ + if (IsAbortedTransactionBlockState() && + !IsTransactionExitStmt(raw_parse_tree->stmt)) + ereport(ERROR, + (errcode(ERRCODE_IN_FAILED_SQL_TRANSACTION), + errmsg("current transaction is aborted, " + "commands ignored until end of transaction block"), + errdetail_abort())); + + /* + * Create the CachedPlanSource before we do parse analysis, since it + * needs to see the unmodified raw parse tree. + */ + psrc = CreateCachedPlan(raw_parse_tree, query_string, + CreateCommandTag(raw_parse_tree->stmt)); + + /* + * Set up a snapshot if parse analysis will need one. + */ + if (analyze_requires_snapshot(raw_parse_tree)) + { + PushActiveSnapshot(GetTransactionSnapshot()); + snapshot_set = true; + } + + /* + * Analyze and rewrite the query. Note that the originally specified + * parameter set is not required to be complete, so we have to use + * parse_analyze_varparams(). + */ + if (log_parser_stats) + ResetUsage(); + + query = parse_analyze_varparams(raw_parse_tree, + query_string, + ¶mTypes, + &numParams); + + /* + * Check all parameter types got determined. + */ + for (int i = 0; i < numParams; i++) + { + Oid ptype = paramTypes[i]; + + if (ptype == InvalidOid || ptype == UNKNOWNOID) + ereport(ERROR, + (errcode(ERRCODE_INDETERMINATE_DATATYPE), + errmsg("could not determine data type of parameter $%d", + i + 1))); + } + + if (log_parser_stats) + ShowUsage("PARSE ANALYSIS STATISTICS"); + + querytree_list = pg_rewrite_query(query); + + /* Done with the snapshot used for parsing */ + if (snapshot_set) + PopActiveSnapshot(); + } + else + { + /* Empty input string. This is legal. */ + raw_parse_tree = NULL; + psrc = CreateCachedPlan(raw_parse_tree, query_string, + CMDTAG_UNKNOWN); + querytree_list = NIL; + } + + /* + * CachedPlanSource must be a direct child of MessageContext before we + * reparent unnamed_stmt_context under it, else we have a disconnected + * circular subgraph. Klugy, but less so than flipping contexts even more + * above. + */ + if (unnamed_stmt_context) + MemoryContextSetParent(psrc->context, MessageContext); + + /* Finish filling in the CachedPlanSource */ + CompleteCachedPlan(psrc, + querytree_list, + unnamed_stmt_context, + paramTypes, + numParams, + NULL, + NULL, + CURSOR_OPT_PARALLEL_OK, /* allow parallel mode */ + true); /* fixed result */ + + /* If we got a cancel signal during analysis, quit */ + CHECK_FOR_INTERRUPTS(); + + if (is_named) + { + /* + * Store the query as a prepared statement. + */ + StorePreparedStatement(stmt_name, psrc, false); + } + else + { + /* + * We just save the CachedPlanSource into unnamed_stmt_psrc. + */ + SaveCachedPlan(psrc); + unnamed_stmt_psrc = psrc; + } + + MemoryContextSwitchTo(oldcontext); + + /* + * We do NOT close the open transaction command here; that only happens + * when the client sends Sync. Instead, do CommandCounterIncrement just + * in case something happened during parse/plan. + */ + CommandCounterIncrement(); + + /* + * Send ParseComplete. + */ + if (whereToSendOutput == DestRemote) + pq_putemptymessage('1'); + + /* + * Emit duration logging if appropriate. + */ + switch (check_log_duration(msec_str, false)) + { + case 1: + ereport(LOG, + (errmsg("duration: %s ms", msec_str), + errhidestmt(true))); + break; + case 2: + ereport(LOG, + (errmsg("duration: %s ms parse %s: %s", + msec_str, + *stmt_name ? stmt_name : "<unnamed>", + query_string), + errhidestmt(true))); + break; + } + + if (save_log_statement_stats) + ShowUsage("PARSE MESSAGE STATISTICS"); + + debug_query_string = NULL; +} + +/* + * exec_bind_message + * + * Process a "Bind" message to create a portal from a prepared statement + */ +static void +exec_bind_message(StringInfo input_message) +{ + const char *portal_name; + const char *stmt_name; + int numPFormats; + int16 *pformats = NULL; + int numParams; + int numRFormats; + int16 *rformats = NULL; + CachedPlanSource *psrc; + CachedPlan *cplan; + Portal portal; + char *query_string; + char *saved_stmt_name; + ParamListInfo params; + MemoryContext oldContext; + bool save_log_statement_stats = log_statement_stats; + bool snapshot_set = false; + char msec_str[32]; + ParamsErrorCbData params_data; + ErrorContextCallback params_errcxt; + + /* Get the fixed part of the message */ + portal_name = pq_getmsgstring(input_message); + stmt_name = pq_getmsgstring(input_message); + + ereport(DEBUG2, + (errmsg_internal("bind %s to %s", + *portal_name ? portal_name : "<unnamed>", + *stmt_name ? stmt_name : "<unnamed>"))); + + /* Find prepared statement */ + if (stmt_name[0] != '\0') + { + PreparedStatement *pstmt; + + pstmt = FetchPreparedStatement(stmt_name, true); + psrc = pstmt->plansource; + } + else + { + /* special-case the unnamed statement */ + psrc = unnamed_stmt_psrc; + if (!psrc) + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_PSTATEMENT), + errmsg("unnamed prepared statement does not exist"))); + } + + /* + * Report query to various monitoring facilities. + */ + debug_query_string = psrc->query_string; + + pgstat_report_activity(STATE_RUNNING, psrc->query_string); + + set_ps_display("BIND"); + + if (save_log_statement_stats) + ResetUsage(); + + /* + * Start up a transaction command so we can call functions etc. (Note that + * this will normally change current memory context.) Nothing happens if + * we are already in one. This also arms the statement timeout if + * necessary. + */ + start_xact_command(); + + /* Switch back to message context */ + MemoryContextSwitchTo(MessageContext); + + /* Get the parameter format codes */ + numPFormats = pq_getmsgint(input_message, 2); + if (numPFormats > 0) + { + pformats = (int16 *) palloc(numPFormats * sizeof(int16)); + for (int i = 0; i < numPFormats; i++) + pformats[i] = pq_getmsgint(input_message, 2); + } + + /* Get the parameter value count */ + numParams = pq_getmsgint(input_message, 2); + + if (numPFormats > 1 && numPFormats != numParams) + ereport(ERROR, + (errcode(ERRCODE_PROTOCOL_VIOLATION), + errmsg("bind message has %d parameter formats but %d parameters", + numPFormats, numParams))); + + if (numParams != psrc->num_params) + ereport(ERROR, + (errcode(ERRCODE_PROTOCOL_VIOLATION), + errmsg("bind message supplies %d parameters, but prepared statement \"%s\" requires %d", + numParams, stmt_name, psrc->num_params))); + + /* + * If we are in aborted transaction state, the only portals we can + * actually run are those containing COMMIT or ROLLBACK commands. We + * disallow binding anything else to avoid problems with infrastructure + * that expects to run inside a valid transaction. We also disallow + * binding any parameters, since we can't risk calling user-defined I/O + * functions. + */ + if (IsAbortedTransactionBlockState() && + (!(psrc->raw_parse_tree && + IsTransactionExitStmt(psrc->raw_parse_tree->stmt)) || + numParams != 0)) + ereport(ERROR, + (errcode(ERRCODE_IN_FAILED_SQL_TRANSACTION), + errmsg("current transaction is aborted, " + "commands ignored until end of transaction block"), + errdetail_abort())); + + /* + * Create the portal. Allow silent replacement of an existing portal only + * if the unnamed portal is specified. + */ + if (portal_name[0] == '\0') + portal = CreatePortal(portal_name, true, true); + else + portal = CreatePortal(portal_name, false, false); + + /* + * Prepare to copy stuff into the portal's memory context. We do all this + * copying first, because it could possibly fail (out-of-memory) and we + * don't want a failure to occur between GetCachedPlan and + * PortalDefineQuery; that would result in leaking our plancache refcount. + */ + oldContext = MemoryContextSwitchTo(portal->portalContext); + + /* Copy the plan's query string into the portal */ + query_string = pstrdup(psrc->query_string); + + /* Likewise make a copy of the statement name, unless it's unnamed */ + if (stmt_name[0]) + saved_stmt_name = pstrdup(stmt_name); + else + saved_stmt_name = NULL; + + /* + * Set a snapshot if we have parameters to fetch (since the input + * functions might need it) or the query isn't a utility command (and + * hence could require redoing parse analysis and planning). We keep the + * snapshot active till we're done, so that plancache.c doesn't have to + * take new ones. + */ + if (numParams > 0 || + (psrc->raw_parse_tree && + analyze_requires_snapshot(psrc->raw_parse_tree))) + { + PushActiveSnapshot(GetTransactionSnapshot()); + snapshot_set = true; + } + + /* + * Fetch parameters, if any, and store in the portal's memory context. + */ + if (numParams > 0) + { + char **knownTextValues = NULL; /* allocate on first use */ + BindParamCbData one_param_data; + + /* + * Set up an error callback so that if there's an error in this phase, + * we can report the specific parameter causing the problem. + */ + one_param_data.portalName = portal->name; + one_param_data.paramno = -1; + one_param_data.paramval = NULL; + params_errcxt.previous = error_context_stack; + params_errcxt.callback = bind_param_error_callback; + params_errcxt.arg = (void *) &one_param_data; + error_context_stack = ¶ms_errcxt; + + params = makeParamList(numParams); + + for (int paramno = 0; paramno < numParams; paramno++) + { + Oid ptype = psrc->param_types[paramno]; + int32 plength; + Datum pval; + bool isNull; + StringInfoData pbuf; + char csave; + int16 pformat; + + one_param_data.paramno = paramno; + one_param_data.paramval = NULL; + + plength = pq_getmsgint(input_message, 4); + isNull = (plength == -1); + + if (!isNull) + { + const char *pvalue = pq_getmsgbytes(input_message, plength); + + /* + * Rather than copying data around, we just set up a phony + * StringInfo pointing to the correct portion of the message + * buffer. We assume we can scribble on the message buffer so + * as to maintain the convention that StringInfos have a + * trailing null. This is grotty but is a big win when + * dealing with very large parameter strings. + */ + pbuf.data = unconstify(char *, pvalue); + pbuf.maxlen = plength + 1; + pbuf.len = plength; + pbuf.cursor = 0; + + csave = pbuf.data[plength]; + pbuf.data[plength] = '\0'; + } + else + { + pbuf.data = NULL; /* keep compiler quiet */ + csave = 0; + } + + if (numPFormats > 1) + pformat = pformats[paramno]; + else if (numPFormats > 0) + pformat = pformats[0]; + else + pformat = 0; /* default = text */ + + if (pformat == 0) /* text mode */ + { + Oid typinput; + Oid typioparam; + char *pstring; + + getTypeInputInfo(ptype, &typinput, &typioparam); + + /* + * We have to do encoding conversion before calling the + * typinput routine. + */ + if (isNull) + pstring = NULL; + else + pstring = pg_client_to_server(pbuf.data, plength); + + /* Now we can log the input string in case of error */ + one_param_data.paramval = pstring; + + pval = OidInputFunctionCall(typinput, pstring, typioparam, -1); + + one_param_data.paramval = NULL; + + /* + * If we might need to log parameters later, save a copy of + * the converted string in MessageContext; then free the + * result of encoding conversion, if any was done. + */ + if (pstring) + { + if (log_parameter_max_length_on_error != 0) + { + MemoryContext oldcxt; + + oldcxt = MemoryContextSwitchTo(MessageContext); + + if (knownTextValues == NULL) + knownTextValues = + palloc0(numParams * sizeof(char *)); + + if (log_parameter_max_length_on_error < 0) + knownTextValues[paramno] = pstrdup(pstring); + else + { + /* + * We can trim the saved string, knowing that we + * won't print all of it. But we must copy at + * least two more full characters than + * BuildParamLogString wants to use; otherwise it + * might fail to include the trailing ellipsis. + */ + knownTextValues[paramno] = + pnstrdup(pstring, + log_parameter_max_length_on_error + + 2 * MAX_MULTIBYTE_CHAR_LEN); + } + + MemoryContextSwitchTo(oldcxt); + } + if (pstring != pbuf.data) + pfree(pstring); + } + } + else if (pformat == 1) /* binary mode */ + { + Oid typreceive; + Oid typioparam; + StringInfo bufptr; + + /* + * Call the parameter type's binary input converter + */ + getTypeBinaryInputInfo(ptype, &typreceive, &typioparam); + + if (isNull) + bufptr = NULL; + else + bufptr = &pbuf; + + pval = OidReceiveFunctionCall(typreceive, bufptr, typioparam, -1); + + /* Trouble if it didn't eat the whole buffer */ + if (!isNull && pbuf.cursor != pbuf.len) + ereport(ERROR, + (errcode(ERRCODE_INVALID_BINARY_REPRESENTATION), + errmsg("incorrect binary data format in bind parameter %d", + paramno + 1))); + } + else + { + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("unsupported format code: %d", + pformat))); + pval = 0; /* keep compiler quiet */ + } + + /* Restore message buffer contents */ + if (!isNull) + pbuf.data[plength] = csave; + + params->params[paramno].value = pval; + params->params[paramno].isnull = isNull; + + /* + * We mark the params as CONST. This ensures that any custom plan + * makes full use of the parameter values. + */ + params->params[paramno].pflags = PARAM_FLAG_CONST; + params->params[paramno].ptype = ptype; + } + + /* Pop the per-parameter error callback */ + error_context_stack = error_context_stack->previous; + + /* + * Once all parameters have been received, prepare for printing them + * in future errors, if configured to do so. (This is saved in the + * portal, so that they'll appear when the query is executed later.) + */ + if (log_parameter_max_length_on_error != 0) + params->paramValuesStr = + BuildParamLogString(params, + knownTextValues, + log_parameter_max_length_on_error); + } + else + params = NULL; + + /* Done storing stuff in portal's context */ + MemoryContextSwitchTo(oldContext); + + /* + * Set up another error callback so that all the parameters are logged if + * we get an error during the rest of the BIND processing. + */ + params_data.portalName = portal->name; + params_data.params = params; + params_errcxt.previous = error_context_stack; + params_errcxt.callback = ParamsErrorCallback; + params_errcxt.arg = (void *) ¶ms_data; + error_context_stack = ¶ms_errcxt; + + /* Get the result format codes */ + numRFormats = pq_getmsgint(input_message, 2); + if (numRFormats > 0) + { + rformats = (int16 *) palloc(numRFormats * sizeof(int16)); + for (int i = 0; i < numRFormats; i++) + rformats[i] = pq_getmsgint(input_message, 2); + } + + pq_getmsgend(input_message); + + /* + * Obtain a plan from the CachedPlanSource. Any cruft from (re)planning + * will be generated in MessageContext. The plan refcount will be + * assigned to the Portal, so it will be released at portal destruction. + */ + cplan = GetCachedPlan(psrc, params, NULL, NULL); + + /* + * Now we can define the portal. + * + * DO NOT put any code that could possibly throw an error between the + * above GetCachedPlan call and here. + */ + PortalDefineQuery(portal, + saved_stmt_name, + query_string, + psrc->commandTag, + cplan->stmt_list, + cplan); + + /* Done with the snapshot used for parameter I/O and parsing/planning */ + if (snapshot_set) + PopActiveSnapshot(); + + /* + * And we're ready to start portal execution. + */ + PortalStart(portal, params, 0, InvalidSnapshot); + + /* + * Apply the result format requests to the portal. + */ + PortalSetResultFormat(portal, numRFormats, rformats); + + /* + * Done binding; remove the parameters error callback. Entries emitted + * later determine independently whether to log the parameters or not. + */ + error_context_stack = error_context_stack->previous; + + /* + * Send BindComplete. + */ + if (whereToSendOutput == DestRemote) + pq_putemptymessage('2'); + + /* + * Emit duration logging if appropriate. + */ + switch (check_log_duration(msec_str, false)) + { + case 1: + ereport(LOG, + (errmsg("duration: %s ms", msec_str), + errhidestmt(true))); + break; + case 2: + ereport(LOG, + (errmsg("duration: %s ms bind %s%s%s: %s", + msec_str, + *stmt_name ? stmt_name : "<unnamed>", + *portal_name ? "/" : "", + *portal_name ? portal_name : "", + psrc->query_string), + errhidestmt(true), + errdetail_params(params))); + break; + } + + if (save_log_statement_stats) + ShowUsage("BIND MESSAGE STATISTICS"); + + debug_query_string = NULL; +} + +/* + * exec_execute_message + * + * Process an "Execute" message for a portal + */ +static void +exec_execute_message(const char *portal_name, long max_rows) +{ + CommandDest dest; + DestReceiver *receiver; + Portal portal; + bool completed; + QueryCompletion qc; + const char *sourceText; + const char *prepStmtName; + ParamListInfo portalParams; + bool save_log_statement_stats = log_statement_stats; + bool is_xact_command; + bool execute_is_fetch; + bool was_logged = false; + char msec_str[32]; + ParamsErrorCbData params_data; + ErrorContextCallback params_errcxt; + + /* Adjust destination to tell printtup.c what to do */ + dest = whereToSendOutput; + if (dest == DestRemote) + dest = DestRemoteExecute; + + portal = GetPortalByName(portal_name); + if (!PortalIsValid(portal)) + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_CURSOR), + errmsg("portal \"%s\" does not exist", portal_name))); + + /* + * If the original query was a null string, just return + * EmptyQueryResponse. + */ + if (portal->commandTag == CMDTAG_UNKNOWN) + { + Assert(portal->stmts == NIL); + NullCommand(dest); + return; + } + + /* Does the portal contain a transaction command? */ + is_xact_command = IsTransactionStmtList(portal->stmts); + + /* + * We must copy the sourceText and prepStmtName into MessageContext in + * case the portal is destroyed during finish_xact_command. We do not + * make a copy of the portalParams though, preferring to just not print + * them in that case. + */ + sourceText = pstrdup(portal->sourceText); + if (portal->prepStmtName) + prepStmtName = pstrdup(portal->prepStmtName); + else + prepStmtName = "<unnamed>"; + portalParams = portal->portalParams; + + /* + * Report query to various monitoring facilities. + */ + debug_query_string = sourceText; + + pgstat_report_activity(STATE_RUNNING, sourceText); + + set_ps_display(GetCommandTagName(portal->commandTag)); + + if (save_log_statement_stats) + ResetUsage(); + + BeginCommand(portal->commandTag, dest); + + /* + * Create dest receiver in MessageContext (we don't want it in transaction + * context, because that may get deleted if portal contains VACUUM). + */ + receiver = CreateDestReceiver(dest); + if (dest == DestRemoteExecute) + SetRemoteDestReceiverParams(receiver, portal); + + /* + * Ensure we are in a transaction command (this should normally be the + * case already due to prior BIND). + */ + start_xact_command(); + + /* + * If we re-issue an Execute protocol request against an existing portal, + * then we are only fetching more rows rather than completely re-executing + * the query from the start. atStart is never reset for a v3 portal, so we + * are safe to use this check. + */ + execute_is_fetch = !portal->atStart; + + /* Log immediately if dictated by log_statement */ + if (check_log_statement(portal->stmts)) + { + ereport(LOG, + (errmsg("%s %s%s%s: %s", + execute_is_fetch ? + _("execute fetch from") : + _("execute"), + prepStmtName, + *portal_name ? "/" : "", + *portal_name ? portal_name : "", + sourceText), + errhidestmt(true), + errdetail_params(portalParams))); + was_logged = true; + } + + /* + * If we are in aborted transaction state, the only portals we can + * actually run are those containing COMMIT or ROLLBACK commands. + */ + if (IsAbortedTransactionBlockState() && + !IsTransactionExitStmtList(portal->stmts)) + ereport(ERROR, + (errcode(ERRCODE_IN_FAILED_SQL_TRANSACTION), + errmsg("current transaction is aborted, " + "commands ignored until end of transaction block"), + errdetail_abort())); + + /* Check for cancel signal before we start execution */ + CHECK_FOR_INTERRUPTS(); + + /* + * Okay to run the portal. Set the error callback so that parameters are + * logged. The parameters must have been saved during the bind phase. + */ + params_data.portalName = portal->name; + params_data.params = portalParams; + params_errcxt.previous = error_context_stack; + params_errcxt.callback = ParamsErrorCallback; + params_errcxt.arg = (void *) ¶ms_data; + error_context_stack = ¶ms_errcxt; + + if (max_rows <= 0) + max_rows = FETCH_ALL; + + completed = PortalRun(portal, + max_rows, + true, /* always top level */ + !execute_is_fetch && max_rows == FETCH_ALL, + receiver, + receiver, + &qc); + + receiver->rDestroy(receiver); + + /* Done executing; remove the params error callback */ + error_context_stack = error_context_stack->previous; + + if (completed) + { + if (is_xact_command || (MyXactFlags & XACT_FLAGS_NEEDIMMEDIATECOMMIT)) + { + /* + * If this was a transaction control statement, commit it. We + * will start a new xact command for the next command (if any). + * Likewise if the statement required immediate commit. Without + * this provision, we wouldn't force commit until Sync is + * received, which creates a hazard if the client tries to + * pipeline immediate-commit statements. + */ + finish_xact_command(); + + /* + * These commands typically don't have any parameters, and even if + * one did we couldn't print them now because the storage went + * away during finish_xact_command. So pretend there were none. + */ + portalParams = NULL; + } + else + { + /* + * We need a CommandCounterIncrement after every query, except + * those that start or end a transaction block. + */ + CommandCounterIncrement(); + + /* + * Disable statement timeout whenever we complete an Execute + * message. The next protocol message will start a fresh timeout. + */ + disable_statement_timeout(); + } + + /* Send appropriate CommandComplete to client */ + EndCommand(&qc, dest, false); + } + else + { + /* Portal run not complete, so send PortalSuspended */ + if (whereToSendOutput == DestRemote) + pq_putemptymessage('s'); + } + + /* + * Emit duration logging if appropriate. + */ + switch (check_log_duration(msec_str, was_logged)) + { + case 1: + ereport(LOG, + (errmsg("duration: %s ms", msec_str), + errhidestmt(true))); + break; + case 2: + ereport(LOG, + (errmsg("duration: %s ms %s %s%s%s: %s", + msec_str, + execute_is_fetch ? + _("execute fetch from") : + _("execute"), + prepStmtName, + *portal_name ? "/" : "", + *portal_name ? portal_name : "", + sourceText), + errhidestmt(true), + errdetail_params(portalParams))); + break; + } + + if (save_log_statement_stats) + ShowUsage("EXECUTE MESSAGE STATISTICS"); + + debug_query_string = NULL; +} + +/* + * check_log_statement + * Determine whether command should be logged because of log_statement + * + * stmt_list can be either raw grammar output or a list of planned + * statements + */ +static bool +check_log_statement(List *stmt_list) +{ + ListCell *stmt_item; + + if (log_statement == LOGSTMT_NONE) + return false; + if (log_statement == LOGSTMT_ALL) + return true; + + /* Else we have to inspect the statement(s) to see whether to log */ + foreach(stmt_item, stmt_list) + { + Node *stmt = (Node *) lfirst(stmt_item); + + if (GetCommandLogLevel(stmt) <= log_statement) + return true; + } + + return false; +} + +/* + * check_log_duration + * Determine whether current command's duration should be logged + * We also check if this statement in this transaction must be logged + * (regardless of its duration). + * + * Returns: + * 0 if no logging is needed + * 1 if just the duration should be logged + * 2 if duration and query details should be logged + * + * If logging is needed, the duration in msec is formatted into msec_str[], + * which must be a 32-byte buffer. + * + * was_logged should be true if caller already logged query details (this + * essentially prevents 2 from being returned). + */ +int +check_log_duration(char *msec_str, bool was_logged) +{ + if (log_duration || log_min_duration_sample >= 0 || + log_min_duration_statement >= 0 || xact_is_sampled) + { + long secs; + int usecs; + int msecs; + bool exceeded_duration; + bool exceeded_sample_duration; + bool in_sample = false; + + TimestampDifference(GetCurrentStatementStartTimestamp(), + GetCurrentTimestamp(), + &secs, &usecs); + msecs = usecs / 1000; + + /* + * This odd-looking test for log_min_duration_* being exceeded is + * designed to avoid integer overflow with very long durations: don't + * compute secs * 1000 until we've verified it will fit in int. + */ + exceeded_duration = (log_min_duration_statement == 0 || + (log_min_duration_statement > 0 && + (secs > log_min_duration_statement / 1000 || + secs * 1000 + msecs >= log_min_duration_statement))); + + exceeded_sample_duration = (log_min_duration_sample == 0 || + (log_min_duration_sample > 0 && + (secs > log_min_duration_sample / 1000 || + secs * 1000 + msecs >= log_min_duration_sample))); + + /* + * Do not log if log_statement_sample_rate = 0. Log a sample if + * log_statement_sample_rate <= 1 and avoid unnecessary random() call + * if log_statement_sample_rate = 1. + */ + if (exceeded_sample_duration) + in_sample = log_statement_sample_rate != 0 && + (log_statement_sample_rate == 1 || + random() <= log_statement_sample_rate * MAX_RANDOM_VALUE); + + if (exceeded_duration || in_sample || log_duration || xact_is_sampled) + { + snprintf(msec_str, 32, "%ld.%03d", + secs * 1000 + msecs, usecs % 1000); + if ((exceeded_duration || in_sample || xact_is_sampled) && !was_logged) + return 2; + else + return 1; + } + } + + return 0; +} + +/* + * errdetail_execute + * + * Add an errdetail() line showing the query referenced by an EXECUTE, if any. + * The argument is the raw parsetree list. + */ +static int +errdetail_execute(List *raw_parsetree_list) +{ + ListCell *parsetree_item; + + foreach(parsetree_item, raw_parsetree_list) + { + RawStmt *parsetree = lfirst_node(RawStmt, parsetree_item); + + if (IsA(parsetree->stmt, ExecuteStmt)) + { + ExecuteStmt *stmt = (ExecuteStmt *) parsetree->stmt; + PreparedStatement *pstmt; + + pstmt = FetchPreparedStatement(stmt->name, false); + if (pstmt) + { + errdetail("prepare: %s", pstmt->plansource->query_string); + return 0; + } + } + } + + return 0; +} + +/* + * errdetail_params + * + * Add an errdetail() line showing bind-parameter data, if available. + * Note that this is only used for statement logging, so it is controlled + * by log_parameter_max_length not log_parameter_max_length_on_error. + */ +static int +errdetail_params(ParamListInfo params) +{ + if (params && params->numParams > 0 && log_parameter_max_length != 0) + { + char *str; + + str = BuildParamLogString(params, NULL, log_parameter_max_length); + if (str && str[0] != '\0') + errdetail("parameters: %s", str); + } + + return 0; +} + +/* + * errdetail_abort + * + * Add an errdetail() line showing abort reason, if any. + */ +static int +errdetail_abort(void) +{ + if (MyProc->recoveryConflictPending) + errdetail("abort reason: recovery conflict"); + + return 0; +} + +/* + * errdetail_recovery_conflict + * + * Add an errdetail() line showing conflict source. + */ +static int +errdetail_recovery_conflict(void) +{ + switch (RecoveryConflictReason) + { + case PROCSIG_RECOVERY_CONFLICT_BUFFERPIN: + errdetail("User was holding shared buffer pin for too long."); + break; + case PROCSIG_RECOVERY_CONFLICT_LOCK: + errdetail("User was holding a relation lock for too long."); + break; + case PROCSIG_RECOVERY_CONFLICT_TABLESPACE: + errdetail("User was or might have been using tablespace that must be dropped."); + break; + case PROCSIG_RECOVERY_CONFLICT_SNAPSHOT: + errdetail("User query might have needed to see row versions that must be removed."); + break; + case PROCSIG_RECOVERY_CONFLICT_STARTUP_DEADLOCK: + errdetail("User transaction caused buffer deadlock with recovery."); + break; + case PROCSIG_RECOVERY_CONFLICT_DATABASE: + errdetail("User was connected to a database that must be dropped."); + break; + default: + break; + /* no errdetail */ + } + + return 0; +} + +/* + * bind_param_error_callback + * + * Error context callback used while parsing parameters in a Bind message + */ +static void +bind_param_error_callback(void *arg) +{ + BindParamCbData *data = (BindParamCbData *) arg; + StringInfoData buf; + char *quotedval; + + if (data->paramno < 0) + return; + + /* If we have a textual value, quote it, and trim if necessary */ + if (data->paramval) + { + initStringInfo(&buf); + appendStringInfoStringQuoted(&buf, data->paramval, + log_parameter_max_length_on_error); + quotedval = buf.data; + } + else + quotedval = NULL; + + if (data->portalName && data->portalName[0] != '\0') + { + if (quotedval) + errcontext("portal \"%s\" parameter $%d = %s", + data->portalName, data->paramno + 1, quotedval); + else + errcontext("portal \"%s\" parameter $%d", + data->portalName, data->paramno + 1); + } + else + { + if (quotedval) + errcontext("unnamed portal parameter $%d = %s", + data->paramno + 1, quotedval); + else + errcontext("unnamed portal parameter $%d", + data->paramno + 1); + } + + if (quotedval) + pfree(quotedval); +} + +/* + * exec_describe_statement_message + * + * Process a "Describe" message for a prepared statement + */ +static void +exec_describe_statement_message(const char *stmt_name) +{ + CachedPlanSource *psrc; + + /* + * Start up a transaction command. (Note that this will normally change + * current memory context.) Nothing happens if we are already in one. + */ + start_xact_command(); + + /* Switch back to message context */ + MemoryContextSwitchTo(MessageContext); + + /* Find prepared statement */ + if (stmt_name[0] != '\0') + { + PreparedStatement *pstmt; + + pstmt = FetchPreparedStatement(stmt_name, true); + psrc = pstmt->plansource; + } + else + { + /* special-case the unnamed statement */ + psrc = unnamed_stmt_psrc; + if (!psrc) + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_PSTATEMENT), + errmsg("unnamed prepared statement does not exist"))); + } + + /* Prepared statements shouldn't have changeable result descs */ + Assert(psrc->fixed_result); + + /* + * If we are in aborted transaction state, we can't run + * SendRowDescriptionMessage(), because that needs catalog accesses. + * Hence, refuse to Describe statements that return data. (We shouldn't + * just refuse all Describes, since that might break the ability of some + * clients to issue COMMIT or ROLLBACK commands, if they use code that + * blindly Describes whatever it does.) We can Describe parameters + * without doing anything dangerous, so we don't restrict that. + */ + if (IsAbortedTransactionBlockState() && + psrc->resultDesc) + ereport(ERROR, + (errcode(ERRCODE_IN_FAILED_SQL_TRANSACTION), + errmsg("current transaction is aborted, " + "commands ignored until end of transaction block"), + errdetail_abort())); + + if (whereToSendOutput != DestRemote) + return; /* can't actually do anything... */ + + /* + * First describe the parameters... + */ + pq_beginmessage_reuse(&row_description_buf, 't'); /* parameter description + * message type */ + pq_sendint16(&row_description_buf, psrc->num_params); + + for (int i = 0; i < psrc->num_params; i++) + { + Oid ptype = psrc->param_types[i]; + + pq_sendint32(&row_description_buf, (int) ptype); + } + pq_endmessage_reuse(&row_description_buf); + + /* + * Next send RowDescription or NoData to describe the result... + */ + if (psrc->resultDesc) + { + List *tlist; + + /* Get the plan's primary targetlist */ + tlist = CachedPlanGetTargetList(psrc, NULL); + + SendRowDescriptionMessage(&row_description_buf, + psrc->resultDesc, + tlist, + NULL); + } + else + pq_putemptymessage('n'); /* NoData */ + +} + +/* + * exec_describe_portal_message + * + * Process a "Describe" message for a portal + */ +static void +exec_describe_portal_message(const char *portal_name) +{ + Portal portal; + + /* + * Start up a transaction command. (Note that this will normally change + * current memory context.) Nothing happens if we are already in one. + */ + start_xact_command(); + + /* Switch back to message context */ + MemoryContextSwitchTo(MessageContext); + + portal = GetPortalByName(portal_name); + if (!PortalIsValid(portal)) + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_CURSOR), + errmsg("portal \"%s\" does not exist", portal_name))); + + /* + * If we are in aborted transaction state, we can't run + * SendRowDescriptionMessage(), because that needs catalog accesses. + * Hence, refuse to Describe portals that return data. (We shouldn't just + * refuse all Describes, since that might break the ability of some + * clients to issue COMMIT or ROLLBACK commands, if they use code that + * blindly Describes whatever it does.) + */ + if (IsAbortedTransactionBlockState() && + portal->tupDesc) + ereport(ERROR, + (errcode(ERRCODE_IN_FAILED_SQL_TRANSACTION), + errmsg("current transaction is aborted, " + "commands ignored until end of transaction block"), + errdetail_abort())); + + if (whereToSendOutput != DestRemote) + return; /* can't actually do anything... */ + + if (portal->tupDesc) + SendRowDescriptionMessage(&row_description_buf, + portal->tupDesc, + FetchPortalTargetList(portal), + portal->formats); + else + pq_putemptymessage('n'); /* NoData */ +} + + +/* + * Convenience routines for starting/committing a single command. + */ +static void +start_xact_command(void) +{ + if (!xact_started) + { + StartTransactionCommand(); + + xact_started = true; + } + + /* + * Start statement timeout if necessary. Note that this'll intentionally + * not reset the clock on an already started timeout, to avoid the timing + * overhead when start_xact_command() is invoked repeatedly, without an + * interceding finish_xact_command() (e.g. parse/bind/execute). If that's + * not desired, the timeout has to be disabled explicitly. + */ + enable_statement_timeout(); + + /* Start timeout for checking if the client has gone away if necessary. */ + if (client_connection_check_interval > 0 && + IsUnderPostmaster && + MyProcPort && + !get_timeout_active(CLIENT_CONNECTION_CHECK_TIMEOUT)) + enable_timeout_after(CLIENT_CONNECTION_CHECK_TIMEOUT, + client_connection_check_interval); +} + +static void +finish_xact_command(void) +{ + /* cancel active statement timeout after each command */ + disable_statement_timeout(); + + if (xact_started) + { + CommitTransactionCommand(); + +#ifdef MEMORY_CONTEXT_CHECKING + /* Check all memory contexts that weren't freed during commit */ + /* (those that were, were checked before being deleted) */ + MemoryContextCheck(TopMemoryContext); +#endif + +#ifdef SHOW_MEMORY_STATS + /* Print mem stats after each commit for leak tracking */ + MemoryContextStats(TopMemoryContext); +#endif + + xact_started = false; + } +} + + +/* + * Convenience routines for checking whether a statement is one of the + * ones that we allow in transaction-aborted state. + */ + +/* Test a bare parsetree */ +static bool +IsTransactionExitStmt(Node *parsetree) +{ + if (parsetree && IsA(parsetree, TransactionStmt)) + { + TransactionStmt *stmt = (TransactionStmt *) parsetree; + + if (stmt->kind == TRANS_STMT_COMMIT || + stmt->kind == TRANS_STMT_PREPARE || + stmt->kind == TRANS_STMT_ROLLBACK || + stmt->kind == TRANS_STMT_ROLLBACK_TO) + return true; + } + return false; +} + +/* Test a list that contains PlannedStmt nodes */ +static bool +IsTransactionExitStmtList(List *pstmts) +{ + if (list_length(pstmts) == 1) + { + PlannedStmt *pstmt = linitial_node(PlannedStmt, pstmts); + + if (pstmt->commandType == CMD_UTILITY && + IsTransactionExitStmt(pstmt->utilityStmt)) + return true; + } + return false; +} + +/* Test a list that contains PlannedStmt nodes */ +static bool +IsTransactionStmtList(List *pstmts) +{ + if (list_length(pstmts) == 1) + { + PlannedStmt *pstmt = linitial_node(PlannedStmt, pstmts); + + if (pstmt->commandType == CMD_UTILITY && + IsA(pstmt->utilityStmt, TransactionStmt)) + return true; + } + return false; +} + +/* Release any existing unnamed prepared statement */ +static void +drop_unnamed_stmt(void) +{ + /* paranoia to avoid a dangling pointer in case of error */ + if (unnamed_stmt_psrc) + { + CachedPlanSource *psrc = unnamed_stmt_psrc; + + unnamed_stmt_psrc = NULL; + DropCachedPlan(psrc); + } +} + + +/* -------------------------------- + * signal handler routines used in PostgresMain() + * -------------------------------- + */ + +/* + * quickdie() occurs when signaled SIGQUIT by the postmaster. + * + * Either some backend has bought the farm, or we've been told to shut down + * "immediately"; so we need to stop what we're doing and exit. + */ +void +quickdie(SIGNAL_ARGS) +{ + sigaddset(&BlockSig, SIGQUIT); /* prevent nested calls */ + PG_SETMASK(&BlockSig); + + /* + * Prevent interrupts while exiting; though we just blocked signals that + * would queue new interrupts, one may have been pending. We don't want a + * quickdie() downgraded to a mere query cancel. + */ + HOLD_INTERRUPTS(); + + /* + * If we're aborting out of client auth, don't risk trying to send + * anything to the client; we will likely violate the protocol, not to + * mention that we may have interrupted the guts of OpenSSL or some + * authentication library. + */ + if (ClientAuthInProgress && whereToSendOutput == DestRemote) + whereToSendOutput = DestNone; + + /* + * Notify the client before exiting, to give a clue on what happened. + * + * It's dubious to call ereport() from a signal handler. It is certainly + * not async-signal safe. But it seems better to try, than to disconnect + * abruptly and leave the client wondering what happened. It's remotely + * possible that we crash or hang while trying to send the message, but + * receiving a SIGQUIT is a sign that something has already gone badly + * wrong, so there's not much to lose. Assuming the postmaster is still + * running, it will SIGKILL us soon if we get stuck for some reason. + * + * One thing we can do to make this a tad safer is to clear the error + * context stack, so that context callbacks are not called. That's a lot + * less code that could be reached here, and the context info is unlikely + * to be very relevant to a SIGQUIT report anyway. + */ + error_context_stack = NULL; + + /* + * When responding to a postmaster-issued signal, we send the message only + * to the client; sending to the server log just creates log spam, plus + * it's more code that we need to hope will work in a signal handler. + * + * Ideally these should be ereport(FATAL), but then we'd not get control + * back to force the correct type of process exit. + */ + switch (GetQuitSignalReason()) + { + case PMQUIT_NOT_SENT: + /* Hmm, SIGQUIT arrived out of the blue */ + ereport(WARNING, + (errcode(ERRCODE_ADMIN_SHUTDOWN), + errmsg("terminating connection because of unexpected SIGQUIT signal"))); + break; + case PMQUIT_FOR_CRASH: + /* A crash-and-restart cycle is in progress */ + ereport(WARNING_CLIENT_ONLY, + (errcode(ERRCODE_CRASH_SHUTDOWN), + errmsg("terminating connection because of crash of another server process"), + errdetail("The postmaster has commanded this server process to roll back" + " the current transaction and exit, because another" + " server process exited abnormally and possibly corrupted" + " shared memory."), + errhint("In a moment you should be able to reconnect to the" + " database and repeat your command."))); + break; + case PMQUIT_FOR_STOP: + /* Immediate-mode stop */ + ereport(WARNING_CLIENT_ONLY, + (errcode(ERRCODE_ADMIN_SHUTDOWN), + errmsg("terminating connection due to immediate shutdown command"))); + break; + } + + /* + * We DO NOT want to run proc_exit() or atexit() callbacks -- we're here + * because shared memory may be corrupted, so we don't want to try to + * clean up our transaction. Just nail the windows shut and get out of + * town. The callbacks wouldn't be safe to run from a signal handler, + * anyway. + * + * Note we do _exit(2) not _exit(0). This is to force the postmaster into + * a system reset cycle if someone sends a manual SIGQUIT to a random + * backend. This is necessary precisely because we don't clean up our + * shared memory state. (The "dead man switch" mechanism in pmsignal.c + * should ensure the postmaster sees this as a crash, too, but no harm in + * being doubly sure.) + */ + _exit(2); +} + +/* + * Shutdown signal from postmaster: abort transaction and exit + * at soonest convenient time + */ +void +die(SIGNAL_ARGS) +{ + int save_errno = errno; + + /* Don't joggle the elbow of proc_exit */ + if (!proc_exit_inprogress) + { + InterruptPending = true; + ProcDiePending = true; + } + + /* for the statistics collector */ + pgStatSessionEndCause = DISCONNECT_KILLED; + + /* If we're still here, waken anything waiting on the process latch */ + SetLatch(MyLatch); + + /* + * If we're in single user mode, we want to quit immediately - we can't + * rely on latches as they wouldn't work when stdin/stdout is a file. + * Rather ugly, but it's unlikely to be worthwhile to invest much more + * effort just for the benefit of single user mode. + */ + if (DoingCommandRead && whereToSendOutput != DestRemote) + ProcessInterrupts(); + + errno = save_errno; +} + +/* + * Query-cancel signal from postmaster: abort current transaction + * at soonest convenient time + */ +void +StatementCancelHandler(SIGNAL_ARGS) +{ + int save_errno = errno; + + /* + * Don't joggle the elbow of proc_exit + */ + if (!proc_exit_inprogress) + { + InterruptPending = true; + QueryCancelPending = true; + } + + /* If we're still here, waken anything waiting on the process latch */ + SetLatch(MyLatch); + + errno = save_errno; +} + +/* signal handler for floating point exception */ +void +FloatExceptionHandler(SIGNAL_ARGS) +{ + /* We're not returning, so no need to save errno */ + ereport(ERROR, + (errcode(ERRCODE_FLOATING_POINT_EXCEPTION), + errmsg("floating-point exception"), + errdetail("An invalid floating-point operation was signaled. " + "This probably means an out-of-range result or an " + "invalid operation, such as division by zero."))); +} + +/* + * RecoveryConflictInterrupt: out-of-line portion of recovery conflict + * handling following receipt of SIGUSR1. Designed to be similar to die() + * and StatementCancelHandler(). Called only by a normal user backend + * that begins a transaction during recovery. + */ +void +RecoveryConflictInterrupt(ProcSignalReason reason) +{ + int save_errno = errno; + + /* + * Don't joggle the elbow of proc_exit + */ + if (!proc_exit_inprogress) + { + RecoveryConflictReason = reason; + switch (reason) + { + case PROCSIG_RECOVERY_CONFLICT_STARTUP_DEADLOCK: + + /* + * If we aren't waiting for a lock we can never deadlock. + */ + if (!IsWaitingForLock()) + return; + + /* Intentional fall through to check wait for pin */ + /* FALLTHROUGH */ + + case PROCSIG_RECOVERY_CONFLICT_BUFFERPIN: + + /* + * If PROCSIG_RECOVERY_CONFLICT_BUFFERPIN is requested but we + * aren't blocking the Startup process there is nothing more + * to do. + * + * When PROCSIG_RECOVERY_CONFLICT_STARTUP_DEADLOCK is + * requested, if we're waiting for locks and the startup + * process is not waiting for buffer pin (i.e., also waiting + * for locks), we set the flag so that ProcSleep() will check + * for deadlocks. + */ + if (!HoldingBufferPinThatDelaysRecovery()) + { + if (reason == PROCSIG_RECOVERY_CONFLICT_STARTUP_DEADLOCK && + GetStartupBufferPinWaitBufId() < 0) + CheckDeadLockAlert(); + return; + } + + MyProc->recoveryConflictPending = true; + + /* Intentional fall through to error handling */ + /* FALLTHROUGH */ + + case PROCSIG_RECOVERY_CONFLICT_LOCK: + case PROCSIG_RECOVERY_CONFLICT_TABLESPACE: + case PROCSIG_RECOVERY_CONFLICT_SNAPSHOT: + + /* + * If we aren't in a transaction any longer then ignore. + */ + if (!IsTransactionOrTransactionBlock()) + return; + + /* + * If we can abort just the current subtransaction then we are + * OK to throw an ERROR to resolve the conflict. Otherwise + * drop through to the FATAL case. + * + * XXX other times that we can throw just an ERROR *may* be + * PROCSIG_RECOVERY_CONFLICT_LOCK if no locks are held in + * parent transactions + * + * PROCSIG_RECOVERY_CONFLICT_SNAPSHOT if no snapshots are held + * by parent transactions and the transaction is not + * transaction-snapshot mode + * + * PROCSIG_RECOVERY_CONFLICT_TABLESPACE if no temp files or + * cursors open in parent transactions + */ + if (!IsSubTransaction()) + { + /* + * If we already aborted then we no longer need to cancel. + * We do this here since we do not wish to ignore aborted + * subtransactions, which must cause FATAL, currently. + */ + if (IsAbortedTransactionBlockState()) + return; + + RecoveryConflictPending = true; + QueryCancelPending = true; + InterruptPending = true; + break; + } + + /* Intentional fall through to session cancel */ + /* FALLTHROUGH */ + + case PROCSIG_RECOVERY_CONFLICT_DATABASE: + RecoveryConflictPending = true; + ProcDiePending = true; + InterruptPending = true; + break; + + default: + elog(FATAL, "unrecognized conflict mode: %d", + (int) reason); + } + + Assert(RecoveryConflictPending && (QueryCancelPending || ProcDiePending)); + + /* + * All conflicts apart from database cause dynamic errors where the + * command or transaction can be retried at a later point with some + * potential for success. No need to reset this, since non-retryable + * conflict errors are currently FATAL. + */ + if (reason == PROCSIG_RECOVERY_CONFLICT_DATABASE) + RecoveryConflictRetryable = false; + } + + /* + * Set the process latch. This function essentially emulates signal + * handlers like die() and StatementCancelHandler() and it seems prudent + * to behave similarly as they do. + */ + SetLatch(MyLatch); + + errno = save_errno; +} + +/* + * ProcessInterrupts: out-of-line portion of CHECK_FOR_INTERRUPTS() macro + * + * If an interrupt condition is pending, and it's safe to service it, + * then clear the flag and accept the interrupt. Called only when + * InterruptPending is true. + * + * Note: if INTERRUPTS_CAN_BE_PROCESSED() is true, then ProcessInterrupts + * is guaranteed to clear the InterruptPending flag before returning. + * (This is not the same as guaranteeing that it's still clear when we + * return; another interrupt could have arrived. But we promise that + * any pre-existing one will have been serviced.) + */ +void +ProcessInterrupts(void) +{ + /* OK to accept any interrupts now? */ + if (InterruptHoldoffCount != 0 || CritSectionCount != 0) + return; + InterruptPending = false; + + if (ProcDiePending) + { + ProcDiePending = false; + QueryCancelPending = false; /* ProcDie trumps QueryCancel */ + LockErrorCleanup(); + /* As in quickdie, don't risk sending to client during auth */ + if (ClientAuthInProgress && whereToSendOutput == DestRemote) + whereToSendOutput = DestNone; + if (ClientAuthInProgress) + ereport(FATAL, + (errcode(ERRCODE_QUERY_CANCELED), + errmsg("canceling authentication due to timeout"))); + else if (IsAutoVacuumWorkerProcess()) + ereport(FATAL, + (errcode(ERRCODE_ADMIN_SHUTDOWN), + errmsg("terminating autovacuum process due to administrator command"))); + else if (IsLogicalWorker()) + ereport(FATAL, + (errcode(ERRCODE_ADMIN_SHUTDOWN), + errmsg("terminating logical replication worker due to administrator command"))); + else if (IsLogicalLauncher()) + { + ereport(DEBUG1, + (errmsg_internal("logical replication launcher shutting down"))); + + /* + * The logical replication launcher can be stopped at any time. + * Use exit status 1 so the background worker is restarted. + */ + proc_exit(1); + } + else if (RecoveryConflictPending && RecoveryConflictRetryable) + { + pgstat_report_recovery_conflict(RecoveryConflictReason); + ereport(FATAL, + (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE), + errmsg("terminating connection due to conflict with recovery"), + errdetail_recovery_conflict())); + } + else if (RecoveryConflictPending) + { + /* Currently there is only one non-retryable recovery conflict */ + Assert(RecoveryConflictReason == PROCSIG_RECOVERY_CONFLICT_DATABASE); + pgstat_report_recovery_conflict(RecoveryConflictReason); + ereport(FATAL, + (errcode(ERRCODE_DATABASE_DROPPED), + errmsg("terminating connection due to conflict with recovery"), + errdetail_recovery_conflict())); + } + else if (IsBackgroundWorker) + ereport(FATAL, + (errcode(ERRCODE_ADMIN_SHUTDOWN), + errmsg("terminating background worker \"%s\" due to administrator command", + MyBgworkerEntry->bgw_type))); + else + ereport(FATAL, + (errcode(ERRCODE_ADMIN_SHUTDOWN), + errmsg("terminating connection due to administrator command"))); + } + + if (CheckClientConnectionPending) + { + CheckClientConnectionPending = false; + + /* + * Check for lost connection and re-arm, if still configured, but not + * if we've arrived back at DoingCommandRead state. We don't want to + * wake up idle sessions, and they already know how to detect lost + * connections. + */ + if (!DoingCommandRead && client_connection_check_interval > 0) + { + if (!pq_check_connection()) + ClientConnectionLost = true; + else + enable_timeout_after(CLIENT_CONNECTION_CHECK_TIMEOUT, + client_connection_check_interval); + } + } + + if (ClientConnectionLost) + { + QueryCancelPending = false; /* lost connection trumps QueryCancel */ + LockErrorCleanup(); + /* don't send to client, we already know the connection to be dead. */ + whereToSendOutput = DestNone; + ereport(FATAL, + (errcode(ERRCODE_CONNECTION_FAILURE), + errmsg("connection to client lost"))); + } + + /* + * If a recovery conflict happens while we are waiting for input from the + * client, the client is presumably just sitting idle in a transaction, + * preventing recovery from making progress. Terminate the connection to + * dislodge it. + */ + if (RecoveryConflictPending && DoingCommandRead) + { + QueryCancelPending = false; /* this trumps QueryCancel */ + RecoveryConflictPending = false; + LockErrorCleanup(); + pgstat_report_recovery_conflict(RecoveryConflictReason); + ereport(FATAL, + (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE), + errmsg("terminating connection due to conflict with recovery"), + errdetail_recovery_conflict(), + errhint("In a moment you should be able to reconnect to the" + " database and repeat your command."))); + } + + /* + * Don't allow query cancel interrupts while reading input from the + * client, because we might lose sync in the FE/BE protocol. (Die + * interrupts are OK, because we won't read any further messages from the + * client in that case.) + */ + if (QueryCancelPending && QueryCancelHoldoffCount != 0) + { + /* + * Re-arm InterruptPending so that we process the cancel request as + * soon as we're done reading the message. (XXX this is seriously + * ugly: it complicates INTERRUPTS_CAN_BE_PROCESSED(), and it means we + * can't use that macro directly as the initial test in this function, + * meaning that this code also creates opportunities for other bugs to + * appear.) + */ + InterruptPending = true; + } + else if (QueryCancelPending) + { + bool lock_timeout_occurred; + bool stmt_timeout_occurred; + + QueryCancelPending = false; + + /* + * If LOCK_TIMEOUT and STATEMENT_TIMEOUT indicators are both set, we + * need to clear both, so always fetch both. + */ + lock_timeout_occurred = get_timeout_indicator(LOCK_TIMEOUT, true); + stmt_timeout_occurred = get_timeout_indicator(STATEMENT_TIMEOUT, true); + + /* + * If both were set, we want to report whichever timeout completed + * earlier; this ensures consistent behavior if the machine is slow + * enough that the second timeout triggers before we get here. A tie + * is arbitrarily broken in favor of reporting a lock timeout. + */ + if (lock_timeout_occurred && stmt_timeout_occurred && + get_timeout_finish_time(STATEMENT_TIMEOUT) < get_timeout_finish_time(LOCK_TIMEOUT)) + lock_timeout_occurred = false; /* report stmt timeout */ + + if (lock_timeout_occurred) + { + LockErrorCleanup(); + ereport(ERROR, + (errcode(ERRCODE_LOCK_NOT_AVAILABLE), + errmsg("canceling statement due to lock timeout"))); + } + if (stmt_timeout_occurred) + { + LockErrorCleanup(); + ereport(ERROR, + (errcode(ERRCODE_QUERY_CANCELED), + errmsg("canceling statement due to statement timeout"))); + } + if (IsAutoVacuumWorkerProcess()) + { + LockErrorCleanup(); + ereport(ERROR, + (errcode(ERRCODE_QUERY_CANCELED), + errmsg("canceling autovacuum task"))); + } + if (RecoveryConflictPending) + { + RecoveryConflictPending = false; + LockErrorCleanup(); + pgstat_report_recovery_conflict(RecoveryConflictReason); + ereport(ERROR, + (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE), + errmsg("canceling statement due to conflict with recovery"), + errdetail_recovery_conflict())); + } + + /* + * If we are reading a command from the client, just ignore the cancel + * request --- sending an extra error message won't accomplish + * anything. Otherwise, go ahead and throw the error. + */ + if (!DoingCommandRead) + { + LockErrorCleanup(); + ereport(ERROR, + (errcode(ERRCODE_QUERY_CANCELED), + errmsg("canceling statement due to user request"))); + } + } + + if (IdleInTransactionSessionTimeoutPending) + { + /* + * If the GUC has been reset to zero, ignore the signal. This is + * important because the GUC update itself won't disable any pending + * interrupt. + */ + if (IdleInTransactionSessionTimeout > 0) + ereport(FATAL, + (errcode(ERRCODE_IDLE_IN_TRANSACTION_SESSION_TIMEOUT), + errmsg("terminating connection due to idle-in-transaction timeout"))); + else + IdleInTransactionSessionTimeoutPending = false; + } + + if (IdleSessionTimeoutPending) + { + /* As above, ignore the signal if the GUC has been reset to zero. */ + if (IdleSessionTimeout > 0) + ereport(FATAL, + (errcode(ERRCODE_IDLE_SESSION_TIMEOUT), + errmsg("terminating connection due to idle-session timeout"))); + else + IdleSessionTimeoutPending = false; + } + + if (ProcSignalBarrierPending) + ProcessProcSignalBarrier(); + + if (ParallelMessagePending) + HandleParallelMessages(); + + if (LogMemoryContextPending) + ProcessLogMemoryContextInterrupt(); +} + + +/* + * IA64-specific code to fetch the AR.BSP register for stack depth checks. + * + * We currently support gcc, icc, and HP-UX's native compiler here. + * + * Note: while icc accepts gcc asm blocks on x86[_64], this is not true on + * ia64 (at least not in icc versions before 12.x). So we have to carry a + * separate implementation for it. + */ +#if defined(__ia64__) || defined(__ia64) + +#if defined(__hpux) && !defined(__GNUC__) && !defined(__INTEL_COMPILER) +/* Assume it's HP-UX native compiler */ +#include <ia64/sys/inline.h> +#define ia64_get_bsp() ((char *) (_Asm_mov_from_ar(_AREG_BSP, _NO_FENCE))) +#elif defined(__INTEL_COMPILER) +/* icc */ +#include <asm/ia64regs.h> +#define ia64_get_bsp() ((char *) __getReg(_IA64_REG_AR_BSP)) +#else +/* gcc */ +static __inline__ char * +ia64_get_bsp(void) +{ + char *ret; + + /* the ;; is a "stop", seems to be required before fetching BSP */ + __asm__ __volatile__( + ";;\n" + " mov %0=ar.bsp \n" +: "=r"(ret)); + + return ret; +} +#endif +#endif /* IA64 */ + + +/* + * set_stack_base: set up reference point for stack depth checking + * + * Returns the old reference point, if any. + */ +pg_stack_base_t +set_stack_base(void) +{ +#ifndef HAVE__BUILTIN_FRAME_ADDRESS + char stack_base; +#endif + pg_stack_base_t old; + +#if defined(__ia64__) || defined(__ia64) + old.stack_base_ptr = stack_base_ptr; + old.register_stack_base_ptr = register_stack_base_ptr; +#else + old = stack_base_ptr; +#endif + + /* + * Set up reference point for stack depth checking. On recent gcc we use + * __builtin_frame_address() to avoid a warning about storing a local + * variable's address in a long-lived variable. + */ +#ifdef HAVE__BUILTIN_FRAME_ADDRESS + stack_base_ptr = __builtin_frame_address(0); +#else + stack_base_ptr = &stack_base; +#endif +#if defined(__ia64__) || defined(__ia64) + register_stack_base_ptr = ia64_get_bsp(); +#endif + + return old; +} + +/* + * restore_stack_base: restore reference point for stack depth checking + * + * This can be used after set_stack_base() to restore the old value. This + * is currently only used in PL/Java. When PL/Java calls a backend function + * from different thread, the thread's stack is at a different location than + * the main thread's stack, so it sets the base pointer before the call, and + * restores it afterwards. + */ +void +restore_stack_base(pg_stack_base_t base) +{ +#if defined(__ia64__) || defined(__ia64) + stack_base_ptr = base.stack_base_ptr; + register_stack_base_ptr = base.register_stack_base_ptr; +#else + stack_base_ptr = base; +#endif +} + +/* + * check_stack_depth/stack_is_too_deep: check for excessively deep recursion + * + * This should be called someplace in any recursive routine that might possibly + * recurse deep enough to overflow the stack. Most Unixen treat stack + * overflow as an unrecoverable SIGSEGV, so we want to error out ourselves + * before hitting the hardware limit. + * + * check_stack_depth() just throws an error summarily. stack_is_too_deep() + * can be used by code that wants to handle the error condition itself. + */ +void +check_stack_depth(void) +{ + if (stack_is_too_deep()) + { + ereport(ERROR, + (errcode(ERRCODE_STATEMENT_TOO_COMPLEX), + errmsg("stack depth limit exceeded"), + errhint("Increase the configuration parameter \"max_stack_depth\" (currently %dkB), " + "after ensuring the platform's stack depth limit is adequate.", + max_stack_depth))); + } +} + +bool +stack_is_too_deep(void) +{ + char stack_top_loc; + long stack_depth; + + /* + * Compute distance from reference point to my local variables + */ + stack_depth = (long) (stack_base_ptr - &stack_top_loc); + + /* + * Take abs value, since stacks grow up on some machines, down on others + */ + if (stack_depth < 0) + stack_depth = -stack_depth; + + /* + * Trouble? + * + * The test on stack_base_ptr prevents us from erroring out if called + * during process setup or in a non-backend process. Logically it should + * be done first, but putting it here avoids wasting cycles during normal + * cases. + */ + if (stack_depth > max_stack_depth_bytes && + stack_base_ptr != NULL) + return true; + + /* + * On IA64 there is a separate "register" stack that requires its own + * independent check. For this, we have to measure the change in the + * "BSP" pointer from PostgresMain to here. Logic is just as above, + * except that we know IA64's register stack grows up. + * + * Note we assume that the same max_stack_depth applies to both stacks. + */ +#if defined(__ia64__) || defined(__ia64) + stack_depth = (long) (ia64_get_bsp() - register_stack_base_ptr); + + if (stack_depth > max_stack_depth_bytes && + register_stack_base_ptr != NULL) + return true; +#endif /* IA64 */ + + return false; +} + +/* GUC check hook for max_stack_depth */ +bool +check_max_stack_depth(int *newval, void **extra, GucSource source) +{ + long newval_bytes = *newval * 1024L; + long stack_rlimit = get_stack_depth_rlimit(); + + if (stack_rlimit > 0 && newval_bytes > stack_rlimit - STACK_DEPTH_SLOP) + { + GUC_check_errdetail("\"max_stack_depth\" must not exceed %ldkB.", + (stack_rlimit - STACK_DEPTH_SLOP) / 1024L); + GUC_check_errhint("Increase the platform's stack depth limit via \"ulimit -s\" or local equivalent."); + return false; + } + return true; +} + +/* GUC assign hook for max_stack_depth */ +void +assign_max_stack_depth(int newval, void *extra) +{ + long newval_bytes = newval * 1024L; + + max_stack_depth_bytes = newval_bytes; +} + + +/* + * set_debug_options --- apply "-d N" command line option + * + * -d is not quite the same as setting log_min_messages because it enables + * other output options. + */ +void +set_debug_options(int debug_flag, GucContext context, GucSource source) +{ + if (debug_flag > 0) + { + char debugstr[64]; + + sprintf(debugstr, "debug%d", debug_flag); + SetConfigOption("log_min_messages", debugstr, context, source); + } + else + SetConfigOption("log_min_messages", "notice", context, source); + + if (debug_flag >= 1 && context == PGC_POSTMASTER) + { + SetConfigOption("log_connections", "true", context, source); + SetConfigOption("log_disconnections", "true", context, source); + } + if (debug_flag >= 2) + SetConfigOption("log_statement", "all", context, source); + if (debug_flag >= 3) + SetConfigOption("debug_print_parse", "true", context, source); + if (debug_flag >= 4) + SetConfigOption("debug_print_plan", "true", context, source); + if (debug_flag >= 5) + SetConfigOption("debug_print_rewritten", "true", context, source); +} + + +bool +set_plan_disabling_options(const char *arg, GucContext context, GucSource source) +{ + const char *tmp = NULL; + + switch (arg[0]) + { + case 's': /* seqscan */ + tmp = "enable_seqscan"; + break; + case 'i': /* indexscan */ + tmp = "enable_indexscan"; + break; + case 'o': /* indexonlyscan */ + tmp = "enable_indexonlyscan"; + break; + case 'b': /* bitmapscan */ + tmp = "enable_bitmapscan"; + break; + case 't': /* tidscan */ + tmp = "enable_tidscan"; + break; + case 'n': /* nestloop */ + tmp = "enable_nestloop"; + break; + case 'm': /* mergejoin */ + tmp = "enable_mergejoin"; + break; + case 'h': /* hashjoin */ + tmp = "enable_hashjoin"; + break; + } + if (tmp) + { + SetConfigOption(tmp, "false", context, source); + return true; + } + else + return false; +} + + +const char * +get_stats_option_name(const char *arg) +{ + switch (arg[0]) + { + case 'p': + if (optarg[1] == 'a') /* "parser" */ + return "log_parser_stats"; + else if (optarg[1] == 'l') /* "planner" */ + return "log_planner_stats"; + break; + + case 'e': /* "executor" */ + return "log_executor_stats"; + break; + } + + return NULL; +} + + +/* ---------------------------------------------------------------- + * process_postgres_switches + * Parse command line arguments for PostgresMain + * + * This is called twice, once for the "secure" options coming from the + * postmaster or command line, and once for the "insecure" options coming + * from the client's startup packet. The latter have the same syntax but + * may be restricted in what they can do. + * + * argv[0] is ignored in either case (it's assumed to be the program name). + * + * ctx is PGC_POSTMASTER for secure options, PGC_BACKEND for insecure options + * coming from the client, or PGC_SU_BACKEND for insecure options coming from + * a superuser client. + * + * If a database name is present in the command line arguments, it's + * returned into *dbname (this is allowed only if *dbname is initially NULL). + * ---------------------------------------------------------------- + */ +void +process_postgres_switches(int argc, char *argv[], GucContext ctx, + const char **dbname) +{ + bool secure = (ctx == PGC_POSTMASTER); + int errs = 0; + GucSource gucsource; + int flag; + + if (secure) + { + gucsource = PGC_S_ARGV; /* switches came from command line */ + + /* Ignore the initial --single argument, if present */ + if (argc > 1 && strcmp(argv[1], "--single") == 0) + { + argv++; + argc--; + } + } + else + { + gucsource = PGC_S_CLIENT; /* switches came from client */ + } + +#ifdef HAVE_INT_OPTERR + + /* + * Turn this off because it's either printed to stderr and not the log + * where we'd want it, or argv[0] is now "--single", which would make for + * a weird error message. We print our own error message below. + */ + opterr = 0; +#endif + + /* + * Parse command-line options. CAUTION: keep this in sync with + * postmaster/postmaster.c (the option sets should not conflict) and with + * the common help() function in main/main.c. + */ + while ((flag = getopt(argc, argv, "B:bc:C:D:d:EeFf:h:ijk:lN:nOPp:r:S:sTt:v:W:-:")) != -1) + { + switch (flag) + { + case 'B': + SetConfigOption("shared_buffers", optarg, ctx, gucsource); + break; + + case 'b': + /* Undocumented flag used for binary upgrades */ + if (secure) + IsBinaryUpgrade = true; + break; + + case 'C': + /* ignored for consistency with the postmaster */ + break; + + case 'D': + if (secure) + userDoption = strdup(optarg); + break; + + case 'd': + set_debug_options(atoi(optarg), ctx, gucsource); + break; + + case 'E': + if (secure) + EchoQuery = true; + break; + + case 'e': + SetConfigOption("datestyle", "euro", ctx, gucsource); + break; + + case 'F': + SetConfigOption("fsync", "false", ctx, gucsource); + break; + + case 'f': + if (!set_plan_disabling_options(optarg, ctx, gucsource)) + errs++; + break; + + case 'h': + SetConfigOption("listen_addresses", optarg, ctx, gucsource); + break; + + case 'i': + SetConfigOption("listen_addresses", "*", ctx, gucsource); + break; + + case 'j': + if (secure) + UseSemiNewlineNewline = true; + break; + + case 'k': + SetConfigOption("unix_socket_directories", optarg, ctx, gucsource); + break; + + case 'l': + SetConfigOption("ssl", "true", ctx, gucsource); + break; + + case 'N': + SetConfigOption("max_connections", optarg, ctx, gucsource); + break; + + case 'n': + /* ignored for consistency with postmaster */ + break; + + case 'O': + SetConfigOption("allow_system_table_mods", "true", ctx, gucsource); + break; + + case 'P': + SetConfigOption("ignore_system_indexes", "true", ctx, gucsource); + break; + + case 'p': + SetConfigOption("port", optarg, ctx, gucsource); + break; + + case 'r': + /* send output (stdout and stderr) to the given file */ + if (secure) + strlcpy(OutputFileName, optarg, MAXPGPATH); + break; + + case 'S': + SetConfigOption("work_mem", optarg, ctx, gucsource); + break; + + case 's': + SetConfigOption("log_statement_stats", "true", ctx, gucsource); + break; + + case 'T': + /* ignored for consistency with the postmaster */ + break; + + case 't': + { + const char *tmp = get_stats_option_name(optarg); + + if (tmp) + SetConfigOption(tmp, "true", ctx, gucsource); + else + errs++; + break; + } + + case 'v': + + /* + * -v is no longer used in normal operation, since + * FrontendProtocol is already set before we get here. We keep + * the switch only for possible use in standalone operation, + * in case we ever support using normal FE/BE protocol with a + * standalone backend. + */ + if (secure) + FrontendProtocol = (ProtocolVersion) atoi(optarg); + break; + + case 'W': + SetConfigOption("post_auth_delay", optarg, ctx, gucsource); + break; + + case 'c': + case '-': + { + char *name, + *value; + + ParseLongOption(optarg, &name, &value); + if (!value) + { + if (flag == '-') + ereport(ERROR, + (errcode(ERRCODE_SYNTAX_ERROR), + errmsg("--%s requires a value", + optarg))); + else + ereport(ERROR, + (errcode(ERRCODE_SYNTAX_ERROR), + errmsg("-c %s requires a value", + optarg))); + } + SetConfigOption(name, value, ctx, gucsource); + free(name); + if (value) + free(value); + break; + } + + default: + errs++; + break; + } + + if (errs) + break; + } + + /* + * Optional database name should be there only if *dbname is NULL. + */ + if (!errs && dbname && *dbname == NULL && argc - optind >= 1) + *dbname = strdup(argv[optind++]); + + if (errs || argc != optind) + { + if (errs) + optind--; /* complain about the previous argument */ + + /* spell the error message a bit differently depending on context */ + if (IsUnderPostmaster) + ereport(FATAL, + errcode(ERRCODE_SYNTAX_ERROR), + errmsg("invalid command-line argument for server process: %s", argv[optind]), + errhint("Try \"%s --help\" for more information.", progname)); + else + ereport(FATAL, + errcode(ERRCODE_SYNTAX_ERROR), + errmsg("%s: invalid command-line argument: %s", + progname, argv[optind]), + errhint("Try \"%s --help\" for more information.", progname)); + } + + /* + * Reset getopt(3) library so that it will work correctly in subprocesses + * or when this function is called a second time with another array. + */ + optind = 1; +#ifdef HAVE_INT_OPTRESET + optreset = 1; /* some systems need this too */ +#endif +} + + +/* ---------------------------------------------------------------- + * PostgresMain + * postgres main loop -- all backends, interactive or otherwise start here + * + * argc/argv are the command line arguments to be used. (When being forked + * by the postmaster, these are not the original argv array of the process.) + * dbname is the name of the database to connect to, or NULL if the database + * name should be extracted from the command line arguments or defaulted. + * username is the PostgreSQL user name to be used for the session. + * ---------------------------------------------------------------- + */ +void +PostgresMain(int argc, char *argv[], + const char *dbname, + const char *username) +{ + int firstchar; + StringInfoData input_message; + sigjmp_buf local_sigjmp_buf; + volatile bool send_ready_for_query = true; + bool idle_in_transaction_timeout_enabled = false; + bool idle_session_timeout_enabled = false; + + /* Initialize startup process environment if necessary. */ + if (!IsUnderPostmaster) + InitStandaloneProcess(argv[0]); + + SetProcessingMode(InitProcessing); + + /* + * Set default values for command-line options. + */ + if (!IsUnderPostmaster) + InitializeGUCOptions(); + + /* + * Parse command-line options. + */ + process_postgres_switches(argc, argv, PGC_POSTMASTER, &dbname); + + /* Must have gotten a database name, or have a default (the username) */ + if (dbname == NULL) + { + dbname = username; + if (dbname == NULL) + ereport(FATAL, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("%s: no database nor user name specified", + progname))); + } + + /* Acquire configuration parameters, unless inherited from postmaster */ + if (!IsUnderPostmaster) + { + if (!SelectConfigFiles(userDoption, progname)) + proc_exit(1); + } + + /* + * Set up signal handlers. (InitPostmasterChild or InitStandaloneProcess + * has already set up BlockSig and made that the active signal mask.) + * + * Note that postmaster blocked all signals before forking child process, + * so there is no race condition whereby we might receive a signal before + * we have set up the handler. + * + * Also note: it's best not to use any signals that are SIG_IGNored in the + * postmaster. If such a signal arrives before we are able to change the + * handler to non-SIG_IGN, it'll get dropped. Instead, make a dummy + * handler in the postmaster to reserve the signal. (Of course, this isn't + * an issue for signals that are locally generated, such as SIGALRM and + * SIGPIPE.) + */ + if (am_walsender) + WalSndSignals(); + else + { + pqsignal(SIGHUP, SignalHandlerForConfigReload); + pqsignal(SIGINT, StatementCancelHandler); /* cancel current query */ + pqsignal(SIGTERM, die); /* cancel current query and exit */ + + /* + * In a postmaster child backend, replace SignalHandlerForCrashExit + * with quickdie, so we can tell the client we're dying. + * + * In a standalone backend, SIGQUIT can be generated from the keyboard + * easily, while SIGTERM cannot, so we make both signals do die() + * rather than quickdie(). + */ + if (IsUnderPostmaster) + pqsignal(SIGQUIT, quickdie); /* hard crash time */ + else + pqsignal(SIGQUIT, die); /* cancel current query and exit */ + InitializeTimeouts(); /* establishes SIGALRM handler */ + + /* + * Ignore failure to write to frontend. Note: if frontend closes + * connection, we will notice it and exit cleanly when control next + * returns to outer loop. This seems safer than forcing exit in the + * midst of output during who-knows-what operation... + */ + pqsignal(SIGPIPE, SIG_IGN); + pqsignal(SIGUSR1, procsignal_sigusr1_handler); + pqsignal(SIGUSR2, SIG_IGN); + pqsignal(SIGFPE, FloatExceptionHandler); + + /* + * Reset some signals that are accepted by postmaster but not by + * backend + */ + pqsignal(SIGCHLD, SIG_DFL); /* system() requires this on some + * platforms */ + } + + if (!IsUnderPostmaster) + { + /* + * Validate we have been given a reasonable-looking DataDir (if under + * postmaster, assume postmaster did this already). + */ + checkDataDir(); + + /* Change into DataDir (if under postmaster, was done already) */ + ChangeToDataDir(); + + /* + * Create lockfile for data directory. + */ + CreateDataDirLockFile(false); + + /* read control file (error checking and contains config ) */ + LocalProcessControlFile(false); + + /* Initialize MaxBackends (if under postmaster, was done already) */ + InitializeMaxBackends(); + } + + /* Early initialization */ + BaseInit(); + + /* + * Create a per-backend PGPROC struct in shared memory, except in the + * EXEC_BACKEND case where this was done in SubPostmasterMain. We must do + * this before we can use LWLocks (and in the EXEC_BACKEND case we already + * had to do some stuff with LWLocks). + */ +#ifdef EXEC_BACKEND + if (!IsUnderPostmaster) + InitProcess(); +#else + InitProcess(); +#endif + + /* We need to allow SIGINT, etc during the initial transaction */ + PG_SETMASK(&UnBlockSig); + + /* + * General initialization. + * + * NOTE: if you are tempted to add code in this vicinity, consider putting + * it inside InitPostgres() instead. In particular, anything that + * involves database access should be there, not here. + */ + InitPostgres(dbname, InvalidOid, username, InvalidOid, NULL, false); + + /* + * If the PostmasterContext is still around, recycle the space; we don't + * need it anymore after InitPostgres completes. Note this does not trash + * *MyProcPort, because ConnCreate() allocated that space with malloc() + * ... else we'd need to copy the Port data first. Also, subsidiary data + * such as the username isn't lost either; see ProcessStartupPacket(). + */ + if (PostmasterContext) + { + MemoryContextDelete(PostmasterContext); + PostmasterContext = NULL; + } + + SetProcessingMode(NormalProcessing); + + /* + * Now all GUC states are fully set up. Report them to client if + * appropriate. + */ + BeginReportingGUCOptions(); + + /* + * Also set up handler to log session end; we have to wait till now to be + * sure Log_disconnections has its final value. + */ + if (IsUnderPostmaster && Log_disconnections) + on_proc_exit(log_disconnections, 0); + + pgstat_report_connect(MyDatabaseId); + + /* Perform initialization specific to a WAL sender process. */ + if (am_walsender) + InitWalSender(); + + /* + * process any libraries that should be preloaded at backend start (this + * likewise can't be done until GUC settings are complete) + */ + process_session_preload_libraries(); + + /* + * Send this backend's cancellation info to the frontend. + */ + if (whereToSendOutput == DestRemote) + { + StringInfoData buf; + + pq_beginmessage(&buf, 'K'); + pq_sendint32(&buf, (int32) MyProcPid); + pq_sendint32(&buf, (int32) MyCancelKey); + pq_endmessage(&buf); + /* Need not flush since ReadyForQuery will do it. */ + } + + /* Welcome banner for standalone case */ + if (whereToSendOutput == DestDebug) + printf("\nPostgreSQL stand-alone backend %s\n", PG_VERSION); + + /* + * Create the memory context we will use in the main loop. + * + * MessageContext is reset once per iteration of the main loop, ie, upon + * completion of processing of each command message from the client. + */ + MessageContext = AllocSetContextCreate(TopMemoryContext, + "MessageContext", + ALLOCSET_DEFAULT_SIZES); + + /* + * Create memory context and buffer used for RowDescription messages. As + * SendRowDescriptionMessage(), via exec_describe_statement_message(), is + * frequently executed for ever single statement, we don't want to + * allocate a separate buffer every time. + */ + row_description_context = AllocSetContextCreate(TopMemoryContext, + "RowDescriptionContext", + ALLOCSET_DEFAULT_SIZES); + MemoryContextSwitchTo(row_description_context); + initStringInfo(&row_description_buf); + MemoryContextSwitchTo(TopMemoryContext); + + /* + * Remember stand-alone backend startup time + */ + if (!IsUnderPostmaster) + PgStartTime = GetCurrentTimestamp(); + + /* + * POSTGRES main processing loop begins here + * + * If an exception is encountered, processing resumes here so we abort the + * current transaction and start a new one. + * + * You might wonder why this isn't coded as an infinite loop around a + * PG_TRY construct. The reason is that this is the bottom of the + * exception stack, and so with PG_TRY there would be no exception handler + * in force at all during the CATCH part. By leaving the outermost setjmp + * always active, we have at least some chance of recovering from an error + * during error recovery. (If we get into an infinite loop thereby, it + * will soon be stopped by overflow of elog.c's internal state stack.) + * + * Note that we use sigsetjmp(..., 1), so that this function's signal mask + * (to wit, UnBlockSig) will be restored when longjmp'ing to here. This + * is essential in case we longjmp'd out of a signal handler on a platform + * where that leaves the signal blocked. It's not redundant with the + * unblock in AbortTransaction() because the latter is only called if we + * were inside a transaction. + */ + + if (sigsetjmp(local_sigjmp_buf, 1) != 0) + { + /* + * NOTE: if you are tempted to add more code in this if-block, + * consider the high probability that it should be in + * AbortTransaction() instead. The only stuff done directly here + * should be stuff that is guaranteed to apply *only* for outer-level + * error recovery, such as adjusting the FE/BE protocol status. + */ + + /* Since not using PG_TRY, must reset error stack by hand */ + error_context_stack = NULL; + + /* Prevent interrupts while cleaning up */ + HOLD_INTERRUPTS(); + + /* + * Forget any pending QueryCancel request, since we're returning to + * the idle loop anyway, and cancel any active timeout requests. (In + * future we might want to allow some timeout requests to survive, but + * at minimum it'd be necessary to do reschedule_timeouts(), in case + * we got here because of a query cancel interrupting the SIGALRM + * interrupt handler.) Note in particular that we must clear the + * statement and lock timeout indicators, to prevent any future plain + * query cancels from being misreported as timeouts in case we're + * forgetting a timeout cancel. + */ + disable_all_timeouts(false); + QueryCancelPending = false; /* second to avoid race condition */ + + /* Not reading from the client anymore. */ + DoingCommandRead = false; + + /* Make sure libpq is in a good state */ + pq_comm_reset(); + + /* Report the error to the client and/or server log */ + EmitErrorReport(); + + /* + * Make sure debug_query_string gets reset before we possibly clobber + * the storage it points at. + */ + debug_query_string = NULL; + + /* + * Abort the current transaction in order to recover. + */ + AbortCurrentTransaction(); + + if (am_walsender) + WalSndErrorCleanup(); + + PortalErrorCleanup(); + + /* + * We can't release replication slots inside AbortTransaction() as we + * need to be able to start and abort transactions while having a slot + * acquired. But we never need to hold them across top level errors, + * so releasing here is fine. There's another cleanup in ProcKill() + * ensuring we'll correctly cleanup on FATAL errors as well. + */ + if (MyReplicationSlot != NULL) + ReplicationSlotRelease(); + + /* We also want to cleanup temporary slots on error. */ + ReplicationSlotCleanup(); + + jit_reset_after_error(); + + /* + * Now return to normal top-level context and clear ErrorContext for + * next time. + */ + MemoryContextSwitchTo(TopMemoryContext); + FlushErrorState(); + + /* + * If we were handling an extended-query-protocol message, initiate + * skip till next Sync. This also causes us not to issue + * ReadyForQuery (until we get Sync). + */ + if (doing_extended_query_message) + ignore_till_sync = true; + + /* We don't have a transaction command open anymore */ + xact_started = false; + + /* + * If an error occurred while we were reading a message from the + * client, we have potentially lost track of where the previous + * message ends and the next one begins. Even though we have + * otherwise recovered from the error, we cannot safely read any more + * messages from the client, so there isn't much we can do with the + * connection anymore. + */ + if (pq_is_reading_msg()) + ereport(FATAL, + (errcode(ERRCODE_PROTOCOL_VIOLATION), + errmsg("terminating connection because protocol synchronization was lost"))); + + /* Now we can allow interrupts again */ + RESUME_INTERRUPTS(); + } + + /* We can now handle ereport(ERROR) */ + PG_exception_stack = &local_sigjmp_buf; + + if (!ignore_till_sync) + send_ready_for_query = true; /* initially, or after error */ + + /* + * Non-error queries loop here. + */ + + for (;;) + { + /* + * At top of loop, reset extended-query-message flag, so that any + * errors encountered in "idle" state don't provoke skip. + */ + doing_extended_query_message = false; + + /* + * Release storage left over from prior query cycle, and create a new + * query input buffer in the cleared MessageContext. + */ + MemoryContextSwitchTo(MessageContext); + MemoryContextResetAndDeleteChildren(MessageContext); + + initStringInfo(&input_message); + + /* + * Also consider releasing our catalog snapshot if any, so that it's + * not preventing advance of global xmin while we wait for the client. + */ + InvalidateCatalogSnapshotConditionally(); + + /* + * (1) If we've reached idle state, tell the frontend we're ready for + * a new query. + * + * Note: this includes fflush()'ing the last of the prior output. + * + * This is also a good time to send collected statistics to the + * collector, and to update the PS stats display. We avoid doing + * those every time through the message loop because it'd slow down + * processing of batched messages, and because we don't want to report + * uncommitted updates (that confuses autovacuum). The notification + * processor wants a call too, if we are not in a transaction block. + * + * Also, if an idle timeout is enabled, start the timer for that. + */ + if (send_ready_for_query) + { + if (IsAbortedTransactionBlockState()) + { + set_ps_display("idle in transaction (aborted)"); + pgstat_report_activity(STATE_IDLEINTRANSACTION_ABORTED, NULL); + + /* Start the idle-in-transaction timer */ + if (IdleInTransactionSessionTimeout > 0) + { + idle_in_transaction_timeout_enabled = true; + enable_timeout_after(IDLE_IN_TRANSACTION_SESSION_TIMEOUT, + IdleInTransactionSessionTimeout); + } + } + else if (IsTransactionOrTransactionBlock()) + { + set_ps_display("idle in transaction"); + pgstat_report_activity(STATE_IDLEINTRANSACTION, NULL); + + /* Start the idle-in-transaction timer */ + if (IdleInTransactionSessionTimeout > 0) + { + idle_in_transaction_timeout_enabled = true; + enable_timeout_after(IDLE_IN_TRANSACTION_SESSION_TIMEOUT, + IdleInTransactionSessionTimeout); + } + } + else + { + /* + * Process incoming notifies (including self-notifies), if + * any, and send relevant messages to the client. Doing it + * here helps ensure stable behavior in tests: if any notifies + * were received during the just-finished transaction, they'll + * be seen by the client before ReadyForQuery is. + */ + if (notifyInterruptPending) + ProcessNotifyInterrupt(false); + + pgstat_report_stat(false); + + set_ps_display("idle"); + pgstat_report_activity(STATE_IDLE, NULL); + + /* Start the idle-session timer */ + if (IdleSessionTimeout > 0) + { + idle_session_timeout_enabled = true; + enable_timeout_after(IDLE_SESSION_TIMEOUT, + IdleSessionTimeout); + } + } + + /* Report any recently-changed GUC options */ + ReportChangedGUCOptions(); + + ReadyForQuery(whereToSendOutput); + send_ready_for_query = false; + } + + /* + * (2) Allow asynchronous signals to be executed immediately if they + * come in while we are waiting for client input. (This must be + * conditional since we don't want, say, reads on behalf of COPY FROM + * STDIN doing the same thing.) + */ + DoingCommandRead = true; + + /* + * (3) read a command (loop blocks here) + */ + firstchar = ReadCommand(&input_message); + + /* + * (4) turn off the idle-in-transaction and idle-session timeouts, if + * active. We do this before step (5) so that any last-moment timeout + * is certain to be detected in step (5). + * + * At most one of these timeouts will be active, so there's no need to + * worry about combining the timeout.c calls into one. + */ + if (idle_in_transaction_timeout_enabled) + { + disable_timeout(IDLE_IN_TRANSACTION_SESSION_TIMEOUT, false); + idle_in_transaction_timeout_enabled = false; + } + if (idle_session_timeout_enabled) + { + disable_timeout(IDLE_SESSION_TIMEOUT, false); + idle_session_timeout_enabled = false; + } + + /* + * (5) disable async signal conditions again. + * + * Query cancel is supposed to be a no-op when there is no query in + * progress, so if a query cancel arrived while we were idle, just + * reset QueryCancelPending. ProcessInterrupts() has that effect when + * it's called when DoingCommandRead is set, so check for interrupts + * before resetting DoingCommandRead. + */ + CHECK_FOR_INTERRUPTS(); + DoingCommandRead = false; + + /* + * (6) check for any other interesting events that happened while we + * slept. + */ + if (ConfigReloadPending) + { + ConfigReloadPending = false; + ProcessConfigFile(PGC_SIGHUP); + } + + /* + * (7) process the command. But ignore it if we're skipping till + * Sync. + */ + if (ignore_till_sync && firstchar != EOF) + continue; + + switch (firstchar) + { + case 'Q': /* simple query */ + { + const char *query_string; + + /* Set statement_timestamp() */ + SetCurrentStatementStartTimestamp(); + + query_string = pq_getmsgstring(&input_message); + pq_getmsgend(&input_message); + + if (am_walsender) + { + if (!exec_replication_command(query_string)) + exec_simple_query(query_string); + } + else + exec_simple_query(query_string); + + send_ready_for_query = true; + } + break; + + case 'P': /* parse */ + { + const char *stmt_name; + const char *query_string; + int numParams; + Oid *paramTypes = NULL; + + forbidden_in_wal_sender(firstchar); + + /* Set statement_timestamp() */ + SetCurrentStatementStartTimestamp(); + + stmt_name = pq_getmsgstring(&input_message); + query_string = pq_getmsgstring(&input_message); + numParams = pq_getmsgint(&input_message, 2); + if (numParams > 0) + { + paramTypes = (Oid *) palloc(numParams * sizeof(Oid)); + for (int i = 0; i < numParams; i++) + paramTypes[i] = pq_getmsgint(&input_message, 4); + } + pq_getmsgend(&input_message); + + exec_parse_message(query_string, stmt_name, + paramTypes, numParams); + } + break; + + case 'B': /* bind */ + forbidden_in_wal_sender(firstchar); + + /* Set statement_timestamp() */ + SetCurrentStatementStartTimestamp(); + + /* + * this message is complex enough that it seems best to put + * the field extraction out-of-line + */ + exec_bind_message(&input_message); + break; + + case 'E': /* execute */ + { + const char *portal_name; + int max_rows; + + forbidden_in_wal_sender(firstchar); + + /* Set statement_timestamp() */ + SetCurrentStatementStartTimestamp(); + + portal_name = pq_getmsgstring(&input_message); + max_rows = pq_getmsgint(&input_message, 4); + pq_getmsgend(&input_message); + + exec_execute_message(portal_name, max_rows); + } + break; + + case 'F': /* fastpath function call */ + forbidden_in_wal_sender(firstchar); + + /* Set statement_timestamp() */ + SetCurrentStatementStartTimestamp(); + + /* Report query to various monitoring facilities. */ + pgstat_report_activity(STATE_FASTPATH, NULL); + set_ps_display("<FASTPATH>"); + + /* start an xact for this function invocation */ + start_xact_command(); + + /* + * Note: we may at this point be inside an aborted + * transaction. We can't throw error for that until we've + * finished reading the function-call message, so + * HandleFunctionRequest() must check for it after doing so. + * Be careful not to do anything that assumes we're inside a + * valid transaction here. + */ + + /* switch back to message context */ + MemoryContextSwitchTo(MessageContext); + + HandleFunctionRequest(&input_message); + + /* commit the function-invocation transaction */ + finish_xact_command(); + + send_ready_for_query = true; + break; + + case 'C': /* close */ + { + int close_type; + const char *close_target; + + forbidden_in_wal_sender(firstchar); + + close_type = pq_getmsgbyte(&input_message); + close_target = pq_getmsgstring(&input_message); + pq_getmsgend(&input_message); + + switch (close_type) + { + case 'S': + if (close_target[0] != '\0') + DropPreparedStatement(close_target, false); + else + { + /* special-case the unnamed statement */ + drop_unnamed_stmt(); + } + break; + case 'P': + { + Portal portal; + + portal = GetPortalByName(close_target); + if (PortalIsValid(portal)) + PortalDrop(portal, false); + } + break; + default: + ereport(ERROR, + (errcode(ERRCODE_PROTOCOL_VIOLATION), + errmsg("invalid CLOSE message subtype %d", + close_type))); + break; + } + + if (whereToSendOutput == DestRemote) + pq_putemptymessage('3'); /* CloseComplete */ + } + break; + + case 'D': /* describe */ + { + int describe_type; + const char *describe_target; + + forbidden_in_wal_sender(firstchar); + + /* Set statement_timestamp() (needed for xact) */ + SetCurrentStatementStartTimestamp(); + + describe_type = pq_getmsgbyte(&input_message); + describe_target = pq_getmsgstring(&input_message); + pq_getmsgend(&input_message); + + switch (describe_type) + { + case 'S': + exec_describe_statement_message(describe_target); + break; + case 'P': + exec_describe_portal_message(describe_target); + break; + default: + ereport(ERROR, + (errcode(ERRCODE_PROTOCOL_VIOLATION), + errmsg("invalid DESCRIBE message subtype %d", + describe_type))); + break; + } + } + break; + + case 'H': /* flush */ + pq_getmsgend(&input_message); + if (whereToSendOutput == DestRemote) + pq_flush(); + break; + + case 'S': /* sync */ + pq_getmsgend(&input_message); + finish_xact_command(); + send_ready_for_query = true; + break; + + /* + * 'X' means that the frontend is closing down the socket. EOF + * means unexpected loss of frontend connection. Either way, + * perform normal shutdown. + */ + case EOF: + + /* for the statistics collector */ + pgStatSessionEndCause = DISCONNECT_CLIENT_EOF; + + /* FALLTHROUGH */ + + case 'X': + + /* + * Reset whereToSendOutput to prevent ereport from attempting + * to send any more messages to client. + */ + if (whereToSendOutput == DestRemote) + whereToSendOutput = DestNone; + + /* + * NOTE: if you are tempted to add more code here, DON'T! + * Whatever you had in mind to do should be set up as an + * on_proc_exit or on_shmem_exit callback, instead. Otherwise + * it will fail to be called during other backend-shutdown + * scenarios. + */ + proc_exit(0); + + case 'd': /* copy data */ + case 'c': /* copy done */ + case 'f': /* copy fail */ + + /* + * Accept but ignore these messages, per protocol spec; we + * probably got here because a COPY failed, and the frontend + * is still sending data. + */ + break; + + default: + ereport(FATAL, + (errcode(ERRCODE_PROTOCOL_VIOLATION), + errmsg("invalid frontend message type %d", + firstchar))); + } + } /* end of input-reading loop */ +} + +/* + * Throw an error if we're a WAL sender process. + * + * This is used to forbid anything else than simple query protocol messages + * in a WAL sender process. 'firstchar' specifies what kind of a forbidden + * message was received, and is used to construct the error message. + */ +static void +forbidden_in_wal_sender(char firstchar) +{ + if (am_walsender) + { + if (firstchar == 'F') + ereport(ERROR, + (errcode(ERRCODE_PROTOCOL_VIOLATION), + errmsg("fastpath function calls not supported in a replication connection"))); + else + ereport(ERROR, + (errcode(ERRCODE_PROTOCOL_VIOLATION), + errmsg("extended query protocol not supported in a replication connection"))); + } +} + + +/* + * Obtain platform stack depth limit (in bytes) + * + * Return -1 if unknown + */ +long +get_stack_depth_rlimit(void) +{ +#if defined(HAVE_GETRLIMIT) && defined(RLIMIT_STACK) + static long val = 0; + + /* This won't change after process launch, so check just once */ + if (val == 0) + { + struct rlimit rlim; + + if (getrlimit(RLIMIT_STACK, &rlim) < 0) + val = -1; + else if (rlim.rlim_cur == RLIM_INFINITY) + val = LONG_MAX; + /* rlim_cur is probably of an unsigned type, so check for overflow */ + else if (rlim.rlim_cur >= LONG_MAX) + val = LONG_MAX; + else + val = rlim.rlim_cur; + } + return val; +#else /* no getrlimit */ +#if defined(WIN32) || defined(__CYGWIN__) + /* On Windows we set the backend stack size in src/backend/Makefile */ + return WIN32_STACK_RLIMIT; +#else /* not windows ... give up */ + return -1; +#endif +#endif +} + + +static struct rusage Save_r; +static struct timeval Save_t; + +void +ResetUsage(void) +{ + getrusage(RUSAGE_SELF, &Save_r); + gettimeofday(&Save_t, NULL); +} + +void +ShowUsage(const char *title) +{ + StringInfoData str; + struct timeval user, + sys; + struct timeval elapse_t; + struct rusage r; + + getrusage(RUSAGE_SELF, &r); + gettimeofday(&elapse_t, NULL); + memcpy((char *) &user, (char *) &r.ru_utime, sizeof(user)); + memcpy((char *) &sys, (char *) &r.ru_stime, sizeof(sys)); + if (elapse_t.tv_usec < Save_t.tv_usec) + { + elapse_t.tv_sec--; + elapse_t.tv_usec += 1000000; + } + if (r.ru_utime.tv_usec < Save_r.ru_utime.tv_usec) + { + r.ru_utime.tv_sec--; + r.ru_utime.tv_usec += 1000000; + } + if (r.ru_stime.tv_usec < Save_r.ru_stime.tv_usec) + { + r.ru_stime.tv_sec--; + r.ru_stime.tv_usec += 1000000; + } + + /* + * The only stats we don't show here are ixrss, idrss, isrss. It takes + * some work to interpret them, and most platforms don't fill them in. + */ + initStringInfo(&str); + + appendStringInfoString(&str, "! system usage stats:\n"); + appendStringInfo(&str, + "!\t%ld.%06ld s user, %ld.%06ld s system, %ld.%06ld s elapsed\n", + (long) (r.ru_utime.tv_sec - Save_r.ru_utime.tv_sec), + (long) (r.ru_utime.tv_usec - Save_r.ru_utime.tv_usec), + (long) (r.ru_stime.tv_sec - Save_r.ru_stime.tv_sec), + (long) (r.ru_stime.tv_usec - Save_r.ru_stime.tv_usec), + (long) (elapse_t.tv_sec - Save_t.tv_sec), + (long) (elapse_t.tv_usec - Save_t.tv_usec)); + appendStringInfo(&str, + "!\t[%ld.%06ld s user, %ld.%06ld s system total]\n", + (long) user.tv_sec, + (long) user.tv_usec, + (long) sys.tv_sec, + (long) sys.tv_usec); +#if defined(HAVE_GETRUSAGE) + appendStringInfo(&str, + "!\t%ld kB max resident size\n", +#if defined(__darwin__) + /* in bytes on macOS */ + r.ru_maxrss / 1024 +#else + /* in kilobytes on most other platforms */ + r.ru_maxrss +#endif + ); + appendStringInfo(&str, + "!\t%ld/%ld [%ld/%ld] filesystem blocks in/out\n", + r.ru_inblock - Save_r.ru_inblock, + /* they only drink coffee at dec */ + r.ru_oublock - Save_r.ru_oublock, + r.ru_inblock, r.ru_oublock); + appendStringInfo(&str, + "!\t%ld/%ld [%ld/%ld] page faults/reclaims, %ld [%ld] swaps\n", + r.ru_majflt - Save_r.ru_majflt, + r.ru_minflt - Save_r.ru_minflt, + r.ru_majflt, r.ru_minflt, + r.ru_nswap - Save_r.ru_nswap, + r.ru_nswap); + appendStringInfo(&str, + "!\t%ld [%ld] signals rcvd, %ld/%ld [%ld/%ld] messages rcvd/sent\n", + r.ru_nsignals - Save_r.ru_nsignals, + r.ru_nsignals, + r.ru_msgrcv - Save_r.ru_msgrcv, + r.ru_msgsnd - Save_r.ru_msgsnd, + r.ru_msgrcv, r.ru_msgsnd); + appendStringInfo(&str, + "!\t%ld/%ld [%ld/%ld] voluntary/involuntary context switches\n", + r.ru_nvcsw - Save_r.ru_nvcsw, + r.ru_nivcsw - Save_r.ru_nivcsw, + r.ru_nvcsw, r.ru_nivcsw); +#endif /* HAVE_GETRUSAGE */ + + /* remove trailing newline */ + if (str.data[str.len - 1] == '\n') + str.data[--str.len] = '\0'; + + ereport(LOG, + (errmsg_internal("%s", title), + errdetail_internal("%s", str.data))); + + pfree(str.data); +} + +/* + * on_proc_exit handler to log end of session + */ +static void +log_disconnections(int code, Datum arg) +{ + Port *port = MyProcPort; + long secs; + int usecs; + int msecs; + int hours, + minutes, + seconds; + + TimestampDifference(MyStartTimestamp, + GetCurrentTimestamp(), + &secs, &usecs); + msecs = usecs / 1000; + + hours = secs / SECS_PER_HOUR; + secs %= SECS_PER_HOUR; + minutes = secs / SECS_PER_MINUTE; + seconds = secs % SECS_PER_MINUTE; + + ereport(LOG, + (errmsg("disconnection: session time: %d:%02d:%02d.%03d " + "user=%s database=%s host=%s%s%s", + hours, minutes, seconds, msecs, + port->user_name, port->database_name, port->remote_host, + port->remote_port[0] ? " port=" : "", port->remote_port))); +} + +/* + * Start statement timeout timer, if enabled. + * + * If there's already a timeout running, don't restart the timer. That + * enables compromises between accuracy of timeouts and cost of starting a + * timeout. + */ +static void +enable_statement_timeout(void) +{ + /* must be within an xact */ + Assert(xact_started); + + if (StatementTimeout > 0) + { + if (!get_timeout_active(STATEMENT_TIMEOUT)) + enable_timeout_after(STATEMENT_TIMEOUT, StatementTimeout); + } + else + { + if (get_timeout_active(STATEMENT_TIMEOUT)) + disable_timeout(STATEMENT_TIMEOUT, false); + } +} + +/* + * Disable statement timeout, if active. + */ +static void +disable_statement_timeout(void) +{ + if (get_timeout_active(STATEMENT_TIMEOUT)) + disable_timeout(STATEMENT_TIMEOUT, false); +} |