1 files changed, 652 insertions, 0 deletions

diff --git a/src/bin/pg_test_fsync/pg_test_fsync.c b/src/bin/pg_test_fsync/pg_test_fsync.c
new file mode 100644
index 0000000..f7bc199
--- /dev/null
+++ b/src/bin/pg_test_fsync/pg_test_fsync.c
@@ -0,0 +1,652 @@
+/*
+ *	pg_test_fsync.c
+ *		tests all supported fsync() methods
+ */
+
+#include "postgres_fe.h"
+
+#include <limits.h>
+#include <sys/stat.h>
+#include <sys/time.h>
+#include <fcntl.h>
+#include <time.h>
+#include <unistd.h>
+#include <signal.h>
+
+#include "access/xlogdefs.h"
+#include "common/logging.h"
+#include "common/pg_prng.h"
+#include "getopt_long.h"
+
+/*
+ * put the temp files in the local directory
+ * unless the user specifies otherwise
+ */
+#define FSYNC_FILENAME	"./pg_test_fsync.out"
+
+#define XLOG_BLCKSZ_K	(XLOG_BLCKSZ / 1024)
+
+#define LABEL_FORMAT		"        %-30s"
+#define NA_FORMAT			"%21s\n"
+/* translator: maintain alignment with NA_FORMAT */
+#define OPS_FORMAT			gettext_noop("%13.3f ops/sec  %6.0f usecs/op\n")
+#define USECS_SEC			1000000
+
+/* These are macros to avoid timing the function call overhead. */
+#ifndef WIN32
+#define START_TIMER \
+do { \
+	alarm_triggered = false; \
+	alarm(secs_per_test); \
+	gettimeofday(&start_t, NULL); \
+} while (0)
+#else
+/* WIN32 doesn't support alarm, so we create a thread and sleep there */
+#define START_TIMER \
+do { \
+	alarm_triggered = false; \
+	if (CreateThread(NULL, 0, process_alarm, NULL, 0, NULL) == \
+		INVALID_HANDLE_VALUE) \
+		pg_fatal("could not create thread for alarm"); \
+	gettimeofday(&start_t, NULL); \
+} while (0)
+#endif
+
+#define STOP_TIMER	\
+do { \
+	gettimeofday(&stop_t, NULL); \
+	print_elapse(start_t, stop_t, ops); \
+} while (0)
+
+
+static const char *progname;
+
+static unsigned int secs_per_test = 5;
+static int	needs_unlink = 0;
+static char full_buf[DEFAULT_XLOG_SEG_SIZE],
+		   *buf,
+		   *filename = FSYNC_FILENAME;
+static struct timeval start_t,
+			stop_t;
+static bool alarm_triggered = false;
+
+
+static void handle_args(int argc, char *argv[]);
+static void prepare_buf(void);
+static void test_open(void);
+static void test_non_sync(void);
+static void test_sync(int writes_per_op);
+static void test_open_syncs(void);
+static void test_open_sync(const char *msg, int writes_size);
+static void test_file_descriptor_sync(void);
+
+#ifndef WIN32
+static void process_alarm(int sig);
+#else
+static DWORD WINAPI process_alarm(LPVOID param);
+#endif
+static void signal_cleanup(int sig);
+
+#ifdef HAVE_FSYNC_WRITETHROUGH
+static int	pg_fsync_writethrough(int fd);
+#endif
+static void print_elapse(struct timeval start_t, struct timeval stop_t, int ops);
+
+#define die(msg) pg_fatal("%s: %m", _(msg))
+
+
+int
+main(int argc, char *argv[])
+{
+	pg_logging_init(argv[0]);
+	set_pglocale_pgservice(argv[0], PG_TEXTDOMAIN("pg_test_fsync"));
+	progname = get_progname(argv[0]);
+
+	handle_args(argc, argv);
+
+	/* Prevent leaving behind the test file */
+	pqsignal(SIGINT, signal_cleanup);
+	pqsignal(SIGTERM, signal_cleanup);
+#ifndef WIN32
+	pqsignal(SIGALRM, process_alarm);
+#endif
+#ifdef SIGHUP
+	/* Not defined on win32 */
+	pqsignal(SIGHUP, signal_cleanup);
+#endif
+
+	pg_prng_seed(&pg_global_prng_state, (uint64) time(NULL));
+
+	prepare_buf();
+
+	test_open();
+
+	/* Test using 1 XLOG_BLCKSZ write */
+	test_sync(1);
+
+	/* Test using 2 XLOG_BLCKSZ writes */
+	test_sync(2);
+
+	test_open_syncs();
+
+	test_file_descriptor_sync();
+
+	test_non_sync();
+
+	unlink(filename);
+
+	return 0;
+}
+
+static void
+handle_args(int argc, char *argv[])
+{
+	static struct option long_options[] = {
+		{"filename", required_argument, NULL, 'f'},
+		{"secs-per-test", required_argument, NULL, 's'},
+		{NULL, 0, NULL, 0}
+	};
+
+	int			option;			/* Command line option */
+	int			optindex = 0;	/* used by getopt_long */
+	unsigned long optval;		/* used for option parsing */
+	char	   *endptr;
+
+	if (argc > 1)
+	{
+		if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0)
+		{
+			printf(_("Usage: %s [-f FILENAME] [-s SECS-PER-TEST]\n"), progname);
+			exit(0);
+		}
+		if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0)
+		{
+			puts("pg_test_fsync (PostgreSQL) " PG_VERSION);
+			exit(0);
+		}
+	}
+
+	while ((option = getopt_long(argc, argv, "f:s:",
+								 long_options, &optindex)) != -1)
+	{
+		switch (option)
+		{
+			case 'f':
+				filename = pg_strdup(optarg);
+				break;
+
+			case 's':
+				errno = 0;
+				optval = strtoul(optarg, &endptr, 10);
+
+				if (endptr == optarg || *endptr != '\0' ||
+					errno != 0 || optval != (unsigned int) optval)
+				{
+					pg_log_error("invalid argument for option %s", "--secs-per-test");
+					pg_log_error_hint("Try \"%s --help\" for more information.", progname);
+					exit(1);
+				}
+
+				secs_per_test = (unsigned int) optval;
+				if (secs_per_test == 0)
+					pg_fatal("%s must be in range %u..%u",
+							 "--secs-per-test", 1, UINT_MAX);
+				break;
+
+			default:
+				/* getopt_long already emitted a complaint */
+				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
+				exit(1);
+		}
+	}
+
+	if (argc > optind)
+	{
+		pg_log_error("too many command-line arguments (first is \"%s\")",
+					 argv[optind]);
+		pg_log_error_hint("Try \"%s --help\" for more information.", progname);
+		exit(1);
+	}
+
+	printf(ngettext("%u second per test\n",
+					"%u seconds per test\n",
+					secs_per_test),
+		   secs_per_test);
+#if defined(O_DIRECT)
+	printf(_("O_DIRECT supported on this platform for open_datasync and open_sync.\n"));
+#elif defined(F_NOCACHE)
+	printf(_("F_NOCACHE supported on this platform for open_datasync and open_sync.\n"));
+#else
+	printf(_("Direct I/O is not supported on this platform.\n"));
+#endif
+}
+
+static void
+prepare_buf(void)
+{
+	int			ops;
+
+	/* write random data into buffer */
+	for (ops = 0; ops < DEFAULT_XLOG_SEG_SIZE; ops++)
+		full_buf[ops] = (char) pg_prng_int32(&pg_global_prng_state);
+
+	buf = (char *) TYPEALIGN(XLOG_BLCKSZ, full_buf);
+}
+
+static void
+test_open(void)
+{
+	int			tmpfile;
+
+	/*
+	 * test if we can open the target file
+	 */
+	if ((tmpfile = open(filename, O_RDWR | O_CREAT | PG_BINARY, S_IRUSR | S_IWUSR)) == -1)
+		die("could not open output file");
+	needs_unlink = 1;
+	if (write(tmpfile, full_buf, DEFAULT_XLOG_SEG_SIZE) !=
+		DEFAULT_XLOG_SEG_SIZE)
+		die("write failed");
+
+	/* fsync now so that dirty buffers don't skew later tests */
+	if (fsync(tmpfile) != 0)
+		die("fsync failed");
+
+	close(tmpfile);
+}
+
+static int
+open_direct(const char *path, int flags, mode_t mode)
+{
+	int			fd;
+
+#ifdef O_DIRECT
+	flags |= O_DIRECT;
+#endif
+
+	fd = open(path, flags, mode);
+
+#if !defined(O_DIRECT) && defined(F_NOCACHE)
+	if (fd >= 0 && fcntl(fd, F_NOCACHE, 1) < 0)
+	{
+		int			save_errno = errno;
+
+		close(fd);
+		errno = save_errno;
+		return -1;
+	}
+#endif
+
+	return fd;
+}
+
+static void
+test_sync(int writes_per_op)
+{
+	int			tmpfile,
+				ops,
+				writes;
+	bool		fs_warning = false;
+
+	if (writes_per_op == 1)
+		printf(_("\nCompare file sync methods using one %dkB write:\n"), XLOG_BLCKSZ_K);
+	else
+		printf(_("\nCompare file sync methods using two %dkB writes:\n"), XLOG_BLCKSZ_K);
+	printf(_("(in wal_sync_method preference order, except fdatasync is Linux's default)\n"));
+
+	/*
+	 * Test open_datasync if available
+	 */
+	printf(LABEL_FORMAT, "open_datasync");
+	fflush(stdout);
+
+#ifdef OPEN_DATASYNC_FLAG
+	if ((tmpfile = open_direct(filename, O_RDWR | O_DSYNC | PG_BINARY, 0)) == -1)
+	{
+		printf(NA_FORMAT, _("n/a*"));
+		fs_warning = true;
+	}
+	else
+	{
+		START_TIMER;
+		for (ops = 0; alarm_triggered == false; ops++)
+		{
+			for (writes = 0; writes < writes_per_op; writes++)
+				if (pg_pwrite(tmpfile,
+							  buf,
+							  XLOG_BLCKSZ,
+							  writes * XLOG_BLCKSZ) != XLOG_BLCKSZ)
+					die("write failed");
+		}
+		STOP_TIMER;
+		close(tmpfile);
+	}
+#else
+	printf(NA_FORMAT, _("n/a"));
+#endif
+
+/*
+ * Test fdatasync if available
+ */
+	printf(LABEL_FORMAT, "fdatasync");
+	fflush(stdout);
+
+#ifdef HAVE_FDATASYNC
+	if ((tmpfile = open(filename, O_RDWR | PG_BINARY, 0)) == -1)
+		die("could not open output file");
+	START_TIMER;
+	for (ops = 0; alarm_triggered == false; ops++)
+	{
+		for (writes = 0; writes < writes_per_op; writes++)
+			if (pg_pwrite(tmpfile,
+						  buf,
+						  XLOG_BLCKSZ,
+						  writes * XLOG_BLCKSZ) != XLOG_BLCKSZ)
+				die("write failed");
+		fdatasync(tmpfile);
+	}
+	STOP_TIMER;
+	close(tmpfile);
+#else
+	printf(NA_FORMAT, _("n/a"));
+#endif
+
+/*
+ * Test fsync
+ */
+	printf(LABEL_FORMAT, "fsync");
+	fflush(stdout);
+
+	if ((tmpfile = open(filename, O_RDWR | PG_BINARY, 0)) == -1)
+		die("could not open output file");
+	START_TIMER;
+	for (ops = 0; alarm_triggered == false; ops++)
+	{
+		for (writes = 0; writes < writes_per_op; writes++)
+			if (pg_pwrite(tmpfile,
+						  buf,
+						  XLOG_BLCKSZ,
+						  writes * XLOG_BLCKSZ) != XLOG_BLCKSZ)
+				die("write failed");
+		if (fsync(tmpfile) != 0)
+			die("fsync failed");
+	}
+	STOP_TIMER;
+	close(tmpfile);
+
+/*
+ * If fsync_writethrough is available, test as well
+ */
+	printf(LABEL_FORMAT, "fsync_writethrough");
+	fflush(stdout);
+
+#ifdef HAVE_FSYNC_WRITETHROUGH
+	if ((tmpfile = open(filename, O_RDWR | PG_BINARY, 0)) == -1)
+		die("could not open output file");
+	START_TIMER;
+	for (ops = 0; alarm_triggered == false; ops++)
+	{
+		for (writes = 0; writes < writes_per_op; writes++)
+			if (pg_pwrite(tmpfile,
+						  buf,
+						  XLOG_BLCKSZ,
+						  writes * XLOG_BLCKSZ) != XLOG_BLCKSZ)
+				die("write failed");
+		if (pg_fsync_writethrough(tmpfile) != 0)
+			die("fsync failed");
+	}
+	STOP_TIMER;
+	close(tmpfile);
+#else
+	printf(NA_FORMAT, _("n/a"));
+#endif
+
+/*
+ * Test open_sync if available
+ */
+	printf(LABEL_FORMAT, "open_sync");
+	fflush(stdout);
+
+#ifdef OPEN_SYNC_FLAG
+	if ((tmpfile = open_direct(filename, O_RDWR | OPEN_SYNC_FLAG | PG_BINARY, 0)) == -1)
+	{
+		printf(NA_FORMAT, _("n/a*"));
+		fs_warning = true;
+	}
+	else
+	{
+		START_TIMER;
+		for (ops = 0; alarm_triggered == false; ops++)
+		{
+			for (writes = 0; writes < writes_per_op; writes++)
+				if (pg_pwrite(tmpfile,
+							  buf,
+							  XLOG_BLCKSZ,
+							  writes * XLOG_BLCKSZ) != XLOG_BLCKSZ)
+
+					/*
+					 * This can generate write failures if the filesystem has
+					 * a large block size, e.g. 4k, and there is no support
+					 * for O_DIRECT writes smaller than the file system block
+					 * size, e.g. XFS.
+					 */
+					die("write failed");
+		}
+		STOP_TIMER;
+		close(tmpfile);
+	}
+#else
+	printf(NA_FORMAT, _("n/a"));
+#endif
+
+	if (fs_warning)
+	{
+		printf(_("* This file system and its mount options do not support direct\n"
+				 "  I/O, e.g. ext4 in journaled mode.\n"));
+	}
+}
+
+static void
+test_open_syncs(void)
+{
+	printf(_("\nCompare open_sync with different write sizes:\n"));
+	printf(_("(This is designed to compare the cost of writing 16kB in different write\n"
+			 "open_sync sizes.)\n"));
+
+	test_open_sync(_(" 1 * 16kB open_sync write"), 16);
+	test_open_sync(_(" 2 *  8kB open_sync writes"), 8);
+	test_open_sync(_(" 4 *  4kB open_sync writes"), 4);
+	test_open_sync(_(" 8 *  2kB open_sync writes"), 2);
+	test_open_sync(_("16 *  1kB open_sync writes"), 1);
+}
+
+/*
+ * Test open_sync with different size files
+ */
+static void
+test_open_sync(const char *msg, int writes_size)
+{
+#ifdef OPEN_SYNC_FLAG
+	int			tmpfile,
+				ops,
+				writes;
+#endif
+
+	printf(LABEL_FORMAT, msg);
+	fflush(stdout);
+
+#ifdef OPEN_SYNC_FLAG
+	if ((tmpfile = open_direct(filename, O_RDWR | OPEN_SYNC_FLAG | PG_BINARY, 0)) == -1)
+		printf(NA_FORMAT, _("n/a*"));
+	else
+	{
+		START_TIMER;
+		for (ops = 0; alarm_triggered == false; ops++)
+		{
+			for (writes = 0; writes < 16 / writes_size; writes++)
+				if (pg_pwrite(tmpfile,
+							  buf,
+							  writes_size * 1024,
+							  writes * writes_size * 1024) !=
+					writes_size * 1024)
+					die("write failed");
+		}
+		STOP_TIMER;
+		close(tmpfile);
+	}
+#else
+	printf(NA_FORMAT, _("n/a"));
+#endif
+}
+
+static void
+test_file_descriptor_sync(void)
+{
+	int			tmpfile,
+				ops;
+
+	/*
+	 * Test whether fsync can sync data written on a different descriptor for
+	 * the same file.  This checks the efficiency of multi-process fsyncs
+	 * against the same file. Possibly this should be done with writethrough
+	 * on platforms which support it.
+	 */
+	printf(_("\nTest if fsync on non-write file descriptor is honored:\n"));
+	printf(_("(If the times are similar, fsync() can sync data written on a different\n"
+			 "descriptor.)\n"));
+
+	/*
+	 * first write, fsync and close, which is the normal behavior without
+	 * multiple descriptors
+	 */
+	printf(LABEL_FORMAT, "write, fsync, close");
+	fflush(stdout);
+
+	START_TIMER;
+	for (ops = 0; alarm_triggered == false; ops++)
+	{
+		if ((tmpfile = open(filename, O_RDWR | PG_BINARY, 0)) == -1)
+			die("could not open output file");
+		if (write(tmpfile, buf, XLOG_BLCKSZ) != XLOG_BLCKSZ)
+			die("write failed");
+		if (fsync(tmpfile) != 0)
+			die("fsync failed");
+		close(tmpfile);
+
+		/*
+		 * open and close the file again to be consistent with the following
+		 * test
+		 */
+		if ((tmpfile = open(filename, O_RDWR | PG_BINARY, 0)) == -1)
+			die("could not open output file");
+		close(tmpfile);
+	}
+	STOP_TIMER;
+
+	/*
+	 * Now open, write, close, open again and fsync This simulates processes
+	 * fsyncing each other's writes.
+	 */
+	printf(LABEL_FORMAT, "write, close, fsync");
+	fflush(stdout);
+
+	START_TIMER;
+	for (ops = 0; alarm_triggered == false; ops++)
+	{
+		if ((tmpfile = open(filename, O_RDWR | PG_BINARY, 0)) == -1)
+			die("could not open output file");
+		if (write(tmpfile, buf, XLOG_BLCKSZ) != XLOG_BLCKSZ)
+			die("write failed");
+		close(tmpfile);
+		/* reopen file */
+		if ((tmpfile = open(filename, O_RDWR | PG_BINARY, 0)) == -1)
+			die("could not open output file");
+		if (fsync(tmpfile) != 0)
+			die("fsync failed");
+		close(tmpfile);
+	}
+	STOP_TIMER;
+}
+
+static void
+test_non_sync(void)
+{
+	int			tmpfile,
+				ops;
+
+	/*
+	 * Test a simple write without fsync
+	 */
+	printf(_("\nNon-sync'ed %dkB writes:\n"), XLOG_BLCKSZ_K);
+	printf(LABEL_FORMAT, "write");
+	fflush(stdout);
+
+	if ((tmpfile = open(filename, O_RDWR | PG_BINARY, 0)) == -1)
+		die("could not open output file");
+	START_TIMER;
+	for (ops = 0; alarm_triggered == false; ops++)
+	{
+		if (pg_pwrite(tmpfile, buf, XLOG_BLCKSZ, 0) != XLOG_BLCKSZ)
+			die("write failed");
+	}
+	STOP_TIMER;
+	close(tmpfile);
+}
+
+static void
+signal_cleanup(int signum)
+{
+	/* Delete the file if it exists. Ignore errors */
+	if (needs_unlink)
+		unlink(filename);
+	/* Finish incomplete line on stdout */
+	puts("");
+	exit(signum);
+}
+
+#ifdef HAVE_FSYNC_WRITETHROUGH
+
+static int
+pg_fsync_writethrough(int fd)
+{
+#ifdef WIN32
+	return _commit(fd);
+#elif defined(F_FULLFSYNC)
+	return (fcntl(fd, F_FULLFSYNC, 0) == -1) ? -1 : 0;
+#else
+	errno = ENOSYS;
+	return -1;
+#endif
+}
+#endif
+
+/*
+ * print out the writes per second for tests
+ */
+static void
+print_elapse(struct timeval start_t, struct timeval stop_t, int ops)
+{
+	double		total_time = (stop_t.tv_sec - start_t.tv_sec) +
+	(stop_t.tv_usec - start_t.tv_usec) * 0.000001;
+	double		per_second = ops / total_time;
+	double		avg_op_time_us = (total_time / ops) * USECS_SEC;
+
+	printf(_(OPS_FORMAT), per_second, avg_op_time_us);
+}
+
+#ifndef WIN32
+static void
+process_alarm(int sig)
+{
+	alarm_triggered = true;
+}
+#else
+static DWORD WINAPI
+process_alarm(LPVOID param)
+{
+	/* WIN32 doesn't support alarm, so we create a thread and sleep here */
+	Sleep(secs_per_test * 1000);
+	alarm_triggered = true;
+	ExitThread(0);
+}
+#endif