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Diffstat (limited to 'src/test_thread.c')
| -rw-r--r-- | src/test_thread.c | 635 |
1 files changed, 635 insertions, 0 deletions
diff --git a/src/test_thread.c b/src/test_thread.c new file mode 100644 index 0000000..de0fdb4 --- /dev/null +++ b/src/test_thread.c @@ -0,0 +1,635 @@ +/* +** 2007 September 9 +** +** The author disclaims copyright to this source code. In place of +** a legal notice, here is a blessing: +** +** May you do good and not evil. +** May you find forgiveness for yourself and forgive others. +** May you share freely, never taking more than you give. +** +************************************************************************* +** +** This file contains the implementation of some Tcl commands used to +** test that sqlite3 database handles may be concurrently accessed by +** multiple threads. Right now this only works on unix. +*/ + +#include "sqliteInt.h" +#if defined(INCLUDE_SQLITE_TCL_H) +# include "sqlite_tcl.h" +#else +# include "tcl.h" +#endif + +#if SQLITE_THREADSAFE + +#include <errno.h> + +#if !defined(_MSC_VER) +#include <unistd.h> +#endif + +/* +** One of these is allocated for each thread created by [sqlthread spawn]. +*/ +typedef struct SqlThread SqlThread; +struct SqlThread { + Tcl_ThreadId parent; /* Thread id of parent thread */ + Tcl_Interp *interp; /* Parent interpreter */ + char *zScript; /* The script to execute. */ + char *zVarname; /* Varname in parent script */ +}; + +/* +** A custom Tcl_Event type used by this module. When the event is +** handled, script zScript is evaluated in interpreter interp. If +** the evaluation throws an exception (returns TCL_ERROR), then the +** error is handled by Tcl_BackgroundError(). If no error occurs, +** the result is simply discarded. +*/ +typedef struct EvalEvent EvalEvent; +struct EvalEvent { + Tcl_Event base; /* Base class of type Tcl_Event */ + char *zScript; /* The script to execute. */ + Tcl_Interp *interp; /* The interpreter to execute it in. */ +}; + +static Tcl_ObjCmdProc sqlthread_proc; +static Tcl_ObjCmdProc clock_seconds_proc; +#if SQLITE_OS_UNIX && defined(SQLITE_ENABLE_UNLOCK_NOTIFY) +static Tcl_ObjCmdProc blocking_step_proc; +static Tcl_ObjCmdProc blocking_prepare_v2_proc; +#endif +int Sqlitetest1_Init(Tcl_Interp *); +int Sqlite3_Init(Tcl_Interp *); + +/* Functions from main.c */ +extern const char *sqlite3ErrName(int); + +/* Functions from test1.c */ +extern void *sqlite3TestTextToPtr(const char *); +extern int getDbPointer(Tcl_Interp *, const char *, sqlite3 **); +extern int sqlite3TestMakePointerStr(Tcl_Interp *, char *, void *); +extern int sqlite3TestErrCode(Tcl_Interp *, sqlite3 *, int); + +/* +** Handler for events of type EvalEvent. +*/ +static int SQLITE_TCLAPI tclScriptEvent(Tcl_Event *evPtr, int flags){ + int rc; + EvalEvent *p = (EvalEvent *)evPtr; + rc = Tcl_Eval(p->interp, p->zScript); + if( rc!=TCL_OK ){ + Tcl_BackgroundError(p->interp); + } + UNUSED_PARAMETER(flags); + return 1; +} + +/* +** Register an EvalEvent to evaluate the script pScript in the +** parent interpreter/thread of SqlThread p. +*/ +static void postToParent(SqlThread *p, Tcl_Obj *pScript){ + EvalEvent *pEvent; + char *zMsg; + int nMsg; + + zMsg = Tcl_GetStringFromObj(pScript, &nMsg); + pEvent = (EvalEvent *)ckalloc(sizeof(EvalEvent)+nMsg+1); + pEvent->base.nextPtr = 0; + pEvent->base.proc = tclScriptEvent; + pEvent->zScript = (char *)&pEvent[1]; + memcpy(pEvent->zScript, zMsg, nMsg+1); + pEvent->interp = p->interp; + + Tcl_ThreadQueueEvent(p->parent, (Tcl_Event *)pEvent, TCL_QUEUE_TAIL); + Tcl_ThreadAlert(p->parent); +} + +/* +** The main function for threads created with [sqlthread spawn]. +*/ +static Tcl_ThreadCreateType tclScriptThread(ClientData pSqlThread){ + Tcl_Interp *interp; + Tcl_Obj *pRes; + Tcl_Obj *pList; + int rc; + SqlThread *p = (SqlThread *)pSqlThread; + extern int Sqlitetest_mutex_Init(Tcl_Interp*); + + interp = Tcl_CreateInterp(); + Tcl_CreateObjCommand(interp, "clock_seconds", clock_seconds_proc, 0, 0); + Tcl_CreateObjCommand(interp, "sqlthread", sqlthread_proc, pSqlThread, 0); +#if SQLITE_OS_UNIX && defined(SQLITE_ENABLE_UNLOCK_NOTIFY) + Tcl_CreateObjCommand(interp, "sqlite3_blocking_step", blocking_step_proc,0,0); + Tcl_CreateObjCommand(interp, + "sqlite3_blocking_prepare_v2", blocking_prepare_v2_proc, (void *)1, 0); + Tcl_CreateObjCommand(interp, + "sqlite3_nonblocking_prepare_v2", blocking_prepare_v2_proc, 0, 0); +#endif + Sqlitetest1_Init(interp); + Sqlitetest_mutex_Init(interp); + Sqlite3_Init(interp); + + rc = Tcl_Eval(interp, p->zScript); + pRes = Tcl_GetObjResult(interp); + pList = Tcl_NewObj(); + Tcl_IncrRefCount(pList); + Tcl_IncrRefCount(pRes); + + if( rc!=TCL_OK ){ + Tcl_ListObjAppendElement(interp, pList, Tcl_NewStringObj("error", -1)); + Tcl_ListObjAppendElement(interp, pList, pRes); + postToParent(p, pList); + Tcl_DecrRefCount(pList); + pList = Tcl_NewObj(); + } + + Tcl_ListObjAppendElement(interp, pList, Tcl_NewStringObj("set", -1)); + Tcl_ListObjAppendElement(interp, pList, Tcl_NewStringObj(p->zVarname, -1)); + Tcl_ListObjAppendElement(interp, pList, pRes); + postToParent(p, pList); + + ckfree((void *)p); + Tcl_DecrRefCount(pList); + Tcl_DecrRefCount(pRes); + Tcl_DeleteInterp(interp); + while( Tcl_DoOneEvent(TCL_ALL_EVENTS|TCL_DONT_WAIT) ); + Tcl_ExitThread(0); + TCL_THREAD_CREATE_RETURN; +} + +/* +** sqlthread spawn VARNAME SCRIPT +** +** Spawn a new thread with its own Tcl interpreter and run the +** specified SCRIPT(s) in it. The thread terminates after running +** the script. The result of the script is stored in the variable +** VARNAME. +** +** The caller can wait for the script to terminate using [vwait VARNAME]. +*/ +static int SQLITE_TCLAPI sqlthread_spawn( + ClientData clientData, + Tcl_Interp *interp, + int objc, + Tcl_Obj *CONST objv[] +){ + Tcl_ThreadId x; + SqlThread *pNew; + int rc; + + int nVarname; char *zVarname; + int nScript; char *zScript; + + /* Parameters for thread creation */ + const int nStack = TCL_THREAD_STACK_DEFAULT; + const int flags = TCL_THREAD_NOFLAGS; + + assert(objc==4); + UNUSED_PARAMETER(clientData); + UNUSED_PARAMETER(objc); + + zVarname = Tcl_GetStringFromObj(objv[2], &nVarname); + zScript = Tcl_GetStringFromObj(objv[3], &nScript); + + pNew = (SqlThread *)ckalloc(sizeof(SqlThread)+nVarname+nScript+2); + pNew->zVarname = (char *)&pNew[1]; + pNew->zScript = (char *)&pNew->zVarname[nVarname+1]; + memcpy(pNew->zVarname, zVarname, nVarname+1); + memcpy(pNew->zScript, zScript, nScript+1); + pNew->parent = Tcl_GetCurrentThread(); + pNew->interp = interp; + + rc = Tcl_CreateThread(&x, tclScriptThread, (void *)pNew, nStack, flags); + if( rc!=TCL_OK ){ + Tcl_AppendResult(interp, "Error in Tcl_CreateThread()", 0); + ckfree((char *)pNew); + return TCL_ERROR; + } + + return TCL_OK; +} + +/* +** sqlthread parent SCRIPT +** +** This can be called by spawned threads only. It sends the specified +** script back to the parent thread for execution. The result of +** evaluating the SCRIPT is returned. The parent thread must enter +** the event loop for this to work - otherwise the caller will +** block indefinitely. +** +** NOTE: At the moment, this doesn't work. FIXME. +*/ +static int SQLITE_TCLAPI sqlthread_parent( + ClientData clientData, + Tcl_Interp *interp, + int objc, + Tcl_Obj *CONST objv[] +){ + EvalEvent *pEvent; + char *zMsg; + int nMsg; + SqlThread *p = (SqlThread *)clientData; + + assert(objc==3); + UNUSED_PARAMETER(objc); + + if( p==0 ){ + Tcl_AppendResult(interp, "no parent thread", 0); + return TCL_ERROR; + } + + zMsg = Tcl_GetStringFromObj(objv[2], &nMsg); + pEvent = (EvalEvent *)ckalloc(sizeof(EvalEvent)+nMsg+1); + pEvent->base.nextPtr = 0; + pEvent->base.proc = tclScriptEvent; + pEvent->zScript = (char *)&pEvent[1]; + memcpy(pEvent->zScript, zMsg, nMsg+1); + pEvent->interp = p->interp; + Tcl_ThreadQueueEvent(p->parent, (Tcl_Event *)pEvent, TCL_QUEUE_TAIL); + Tcl_ThreadAlert(p->parent); + + return TCL_OK; +} + +static int xBusy(void *pArg, int nBusy){ + UNUSED_PARAMETER(pArg); + UNUSED_PARAMETER(nBusy); + sqlite3_sleep(50); + return 1; /* Try again... */ +} + +/* +** sqlthread open +** +** Open a database handle and return the string representation of +** the pointer value. +*/ +static int SQLITE_TCLAPI sqlthread_open( + ClientData clientData, + Tcl_Interp *interp, + int objc, + Tcl_Obj *CONST objv[] +){ + int sqlite3TestMakePointerStr(Tcl_Interp *interp, char *zPtr, void *p); + + const char *zFilename; + sqlite3 *db; + char zBuf[100]; + extern int Md5_Register(sqlite3*,char**,const sqlite3_api_routines*); + + UNUSED_PARAMETER(clientData); + UNUSED_PARAMETER(objc); + + zFilename = Tcl_GetString(objv[2]); + sqlite3_open(zFilename, &db); + Md5_Register(db, 0, 0); + sqlite3_busy_handler(db, xBusy, 0); + + if( sqlite3TestMakePointerStr(interp, zBuf, db) ) return TCL_ERROR; + Tcl_AppendResult(interp, zBuf, 0); + + return TCL_OK; +} + + +/* +** sqlthread open +** +** Return the current thread-id (Tcl_GetCurrentThread()) cast to +** an integer. +*/ +static int SQLITE_TCLAPI sqlthread_id( + ClientData clientData, + Tcl_Interp *interp, + int objc, + Tcl_Obj *CONST objv[] +){ + Tcl_ThreadId id = Tcl_GetCurrentThread(); + Tcl_SetObjResult(interp, Tcl_NewIntObj(SQLITE_PTR_TO_INT(id))); + UNUSED_PARAMETER(clientData); + UNUSED_PARAMETER(objc); + UNUSED_PARAMETER(objv); + return TCL_OK; +} + + +/* +** Dispatch routine for the sub-commands of [sqlthread]. +*/ +static int SQLITE_TCLAPI sqlthread_proc( + ClientData clientData, + Tcl_Interp *interp, + int objc, + Tcl_Obj *CONST objv[] +){ + struct SubCommand { + char *zName; + Tcl_ObjCmdProc *xProc; + int nArg; + char *zUsage; + } aSub[] = { + {"parent", sqlthread_parent, 1, "SCRIPT"}, + {"spawn", sqlthread_spawn, 2, "VARNAME SCRIPT"}, + {"open", sqlthread_open, 1, "DBNAME"}, + {"id", sqlthread_id, 0, ""}, + {0, 0, 0} + }; + struct SubCommand *pSub; + int rc; + int iIndex; + + if( objc<2 ){ + Tcl_WrongNumArgs(interp, 1, objv, "SUB-COMMAND"); + return TCL_ERROR; + } + + rc = Tcl_GetIndexFromObjStruct( + interp, objv[1], aSub, sizeof(aSub[0]), "sub-command", 0, &iIndex + ); + if( rc!=TCL_OK ) return rc; + pSub = &aSub[iIndex]; + + if( objc<(pSub->nArg+2) ){ + Tcl_WrongNumArgs(interp, 2, objv, pSub->zUsage); + return TCL_ERROR; + } + + return pSub->xProc(clientData, interp, objc, objv); +} + +/* +** The [clock_seconds] command. This is more or less the same as the +** regular tcl [clock seconds], except that it is available in testfixture +** when linked against both Tcl 8.4 and 8.5. Because [clock seconds] is +** implemented as a script in Tcl 8.5, it is not usually available to +** testfixture. +*/ +static int SQLITE_TCLAPI clock_seconds_proc( + ClientData clientData, + Tcl_Interp *interp, + int objc, + Tcl_Obj *CONST objv[] +){ + Tcl_Time now; + Tcl_GetTime(&now); + Tcl_SetObjResult(interp, Tcl_NewIntObj(now.sec)); + UNUSED_PARAMETER(clientData); + UNUSED_PARAMETER(objc); + UNUSED_PARAMETER(objv); + return TCL_OK; +} + +/************************************************************************* +** This block contains the implementation of the [sqlite3_blocking_step] +** command available to threads created by [sqlthread spawn] commands. It +** is only available on UNIX for now. This is because pthread condition +** variables are used. +** +** The source code for the C functions sqlite3_blocking_step(), +** blocking_step_notify() and the structure UnlockNotification is +** automatically extracted from this file and used as part of the +** documentation for the sqlite3_unlock_notify() API function. This +** should be considered if these functions are to be extended (i.e. to +** support windows) in the future. +*/ +#if SQLITE_OS_UNIX && defined(SQLITE_ENABLE_UNLOCK_NOTIFY) + +/* BEGIN_SQLITE_BLOCKING_STEP */ +/* This example uses the pthreads API */ +#include <pthread.h> + +/* +** A pointer to an instance of this structure is passed as the user-context +** pointer when registering for an unlock-notify callback. +*/ +typedef struct UnlockNotification UnlockNotification; +struct UnlockNotification { + int fired; /* True after unlock event has occurred */ + pthread_cond_t cond; /* Condition variable to wait on */ + pthread_mutex_t mutex; /* Mutex to protect structure */ +}; + +/* +** This function is an unlock-notify callback registered with SQLite. +*/ +static void unlock_notify_cb(void **apArg, int nArg){ + int i; + for(i=0; i<nArg; i++){ + UnlockNotification *p = (UnlockNotification *)apArg[i]; + pthread_mutex_lock(&p->mutex); + p->fired = 1; + pthread_cond_signal(&p->cond); + pthread_mutex_unlock(&p->mutex); + } +} + +/* +** This function assumes that an SQLite API call (either sqlite3_prepare_v2() +** or sqlite3_step()) has just returned SQLITE_LOCKED. The argument is the +** associated database connection. +** +** This function calls sqlite3_unlock_notify() to register for an +** unlock-notify callback, then blocks until that callback is delivered +** and returns SQLITE_OK. The caller should then retry the failed operation. +** +** Or, if sqlite3_unlock_notify() indicates that to block would deadlock +** the system, then this function returns SQLITE_LOCKED immediately. In +** this case the caller should not retry the operation and should roll +** back the current transaction (if any). +*/ +static int wait_for_unlock_notify(sqlite3 *db){ + int rc; + UnlockNotification un; + + /* Initialize the UnlockNotification structure. */ + un.fired = 0; + pthread_mutex_init(&un.mutex, 0); + pthread_cond_init(&un.cond, 0); + + /* Register for an unlock-notify callback. */ + rc = sqlite3_unlock_notify(db, unlock_notify_cb, (void *)&un); + assert( rc==SQLITE_LOCKED || rc==SQLITE_OK ); + + /* The call to sqlite3_unlock_notify() always returns either SQLITE_LOCKED + ** or SQLITE_OK. + ** + ** If SQLITE_LOCKED was returned, then the system is deadlocked. In this + ** case this function needs to return SQLITE_LOCKED to the caller so + ** that the current transaction can be rolled back. Otherwise, block + ** until the unlock-notify callback is invoked, then return SQLITE_OK. + */ + if( rc==SQLITE_OK ){ + pthread_mutex_lock(&un.mutex); + if( !un.fired ){ + pthread_cond_wait(&un.cond, &un.mutex); + } + pthread_mutex_unlock(&un.mutex); + } + + /* Destroy the mutex and condition variables. */ + pthread_cond_destroy(&un.cond); + pthread_mutex_destroy(&un.mutex); + + return rc; +} + +/* +** This function is a wrapper around the SQLite function sqlite3_step(). +** It functions in the same way as step(), except that if a required +** shared-cache lock cannot be obtained, this function may block waiting for +** the lock to become available. In this scenario the normal API step() +** function always returns SQLITE_LOCKED. +** +** If this function returns SQLITE_LOCKED, the caller should rollback +** the current transaction (if any) and try again later. Otherwise, the +** system may become deadlocked. +*/ +int sqlite3_blocking_step(sqlite3_stmt *pStmt){ + int rc; + while( SQLITE_LOCKED==(rc = sqlite3_step(pStmt)) ){ + rc = wait_for_unlock_notify(sqlite3_db_handle(pStmt)); + if( rc!=SQLITE_OK ) break; + sqlite3_reset(pStmt); + } + return rc; +} + +/* +** This function is a wrapper around the SQLite function sqlite3_prepare_v2(). +** It functions in the same way as prepare_v2(), except that if a required +** shared-cache lock cannot be obtained, this function may block waiting for +** the lock to become available. In this scenario the normal API prepare_v2() +** function always returns SQLITE_LOCKED. +** +** If this function returns SQLITE_LOCKED, the caller should rollback +** the current transaction (if any) and try again later. Otherwise, the +** system may become deadlocked. +*/ +int sqlite3_blocking_prepare_v2( + sqlite3 *db, /* Database handle. */ + const char *zSql, /* UTF-8 encoded SQL statement. */ + int nSql, /* Length of zSql in bytes. */ + sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */ + const char **pz /* OUT: End of parsed string */ +){ + int rc; + while( SQLITE_LOCKED==(rc = sqlite3_prepare_v2(db, zSql, nSql, ppStmt, pz)) ){ + rc = wait_for_unlock_notify(db); + if( rc!=SQLITE_OK ) break; + } + return rc; +} +/* END_SQLITE_BLOCKING_STEP */ + +/* +** Usage: sqlite3_blocking_step STMT +** +** Advance the statement to the next row. +*/ +static int SQLITE_TCLAPI blocking_step_proc( + void * clientData, + Tcl_Interp *interp, + int objc, + Tcl_Obj *CONST objv[] +){ + + sqlite3_stmt *pStmt; + int rc; + + if( objc!=2 ){ + Tcl_WrongNumArgs(interp, 1, objv, "STMT"); + return TCL_ERROR; + } + + pStmt = (sqlite3_stmt*)sqlite3TestTextToPtr(Tcl_GetString(objv[1])); + rc = sqlite3_blocking_step(pStmt); + + Tcl_SetResult(interp, (char *)sqlite3ErrName(rc), 0); + return TCL_OK; +} + +/* +** Usage: sqlite3_blocking_prepare_v2 DB sql bytes ?tailvar? +** Usage: sqlite3_nonblocking_prepare_v2 DB sql bytes ?tailvar? +*/ +static int SQLITE_TCLAPI blocking_prepare_v2_proc( + void * clientData, + Tcl_Interp *interp, + int objc, + Tcl_Obj *CONST objv[] +){ + sqlite3 *db; + const char *zSql; + int bytes; + const char *zTail = 0; + sqlite3_stmt *pStmt = 0; + char zBuf[50]; + int rc; + int isBlocking = !(clientData==0); + + if( objc!=5 && objc!=4 ){ + Tcl_AppendResult(interp, "wrong # args: should be \"", + Tcl_GetString(objv[0]), " DB sql bytes tailvar", 0); + return TCL_ERROR; + } + if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR; + zSql = Tcl_GetString(objv[2]); + if( Tcl_GetIntFromObj(interp, objv[3], &bytes) ) return TCL_ERROR; + + if( isBlocking ){ + rc = sqlite3_blocking_prepare_v2(db, zSql, bytes, &pStmt, &zTail); + }else{ + rc = sqlite3_prepare_v2(db, zSql, bytes, &pStmt, &zTail); + } + + assert(rc==SQLITE_OK || pStmt==0); + if( zTail && objc>=5 ){ + if( bytes>=0 ){ + bytes = bytes - (zTail-zSql); + } + Tcl_ObjSetVar2(interp, objv[4], 0, Tcl_NewStringObj(zTail, bytes), 0); + } + if( rc!=SQLITE_OK ){ + assert( pStmt==0 ); + sqlite3_snprintf(sizeof(zBuf), zBuf, "%s ", (char *)sqlite3ErrName(rc)); + Tcl_AppendResult(interp, zBuf, sqlite3_errmsg(db), 0); + return TCL_ERROR; + } + + if( pStmt ){ + if( sqlite3TestMakePointerStr(interp, zBuf, pStmt) ) return TCL_ERROR; + Tcl_AppendResult(interp, zBuf, 0); + } + return TCL_OK; +} + +#endif /* SQLITE_OS_UNIX && SQLITE_ENABLE_UNLOCK_NOTIFY */ +/* +** End of implementation of [sqlite3_blocking_step]. +************************************************************************/ + +/* +** Register commands with the TCL interpreter. +*/ +int SqlitetestThread_Init(Tcl_Interp *interp){ + Tcl_CreateObjCommand(interp, "sqlthread", sqlthread_proc, 0, 0); + Tcl_CreateObjCommand(interp, "clock_seconds", clock_seconds_proc, 0, 0); +#if SQLITE_OS_UNIX && defined(SQLITE_ENABLE_UNLOCK_NOTIFY) + Tcl_CreateObjCommand(interp, "sqlite3_blocking_step", blocking_step_proc,0,0); + Tcl_CreateObjCommand(interp, + "sqlite3_blocking_prepare_v2", blocking_prepare_v2_proc, (void *)1, 0); + Tcl_CreateObjCommand(interp, + "sqlite3_nonblocking_prepare_v2", blocking_prepare_v2_proc, 0, 0); +#endif + return TCL_OK; +} +#else +int SqlitetestThread_Init(Tcl_Interp *interp){ + return TCL_OK; +} +#endif |