Restructure test_fync to use modular C so there is less duplicate code

and it can be enhanced easier.

src/tools/fsync/README

@@ -3,7 +3,7 @@ test_fsync
 
 This program tests fsync.  The tests are described as part of the program output.
 
-	Usage:	test_fsync [-f filename] [loops]
+	Usage:	test_fsync [-f filename] [ops_per_test]
 	
 test_fsync is intended to give you a reasonable idea of what the fastest
 fsync_method is on your specific system, as well as supplying diagnostic
@@ -16,5 +16,6 @@ The output filename defaults to test_fsync.out in the current directory.
 test_fsync should be run in the same filesystem as your transaction log
 directory (pg_xlog).
 
-Loops default to 2000.  Increase this to get more accurate measurements.
+Ops-per-test defaults to 2000.  Increase this to get more accurate
+measurements.
 

src/tools/fsync/test_fsync.c

@@ -22,6 +22,7 @@
 #include <unistd.h>
 #include <string.h>
 
+
 /* 
  * put the temp files in the local directory
  * unless the user specifies otherwise 
@@ -34,21 +35,59 @@
 #define NA_FORMAT		LABEL_FORMAT "%18s"
 
 
-int			loops = 2000;
+int			ops_per_test = 2000;
+char	    full_buf[XLOG_SEG_SIZE], *buf, *filename = FSYNC_FILENAME;
+struct timeval start_t, stop_t;
 
-void		die(char *str);
+
+void		handle_args(int argc, char *argv[]);
+void		prepare_buf(void);
+void		test_open(void);
+void		test_non_sync(void);
+void		test_sync(int writes_per_op);
+void		test_open_syncs(void);
+void		test_file_descriptor_sync(void);
 void		print_elapse(struct timeval start_t, struct timeval stop_t);
+void		die(char *str);
+
 
 int
 main(int argc, char *argv[])
 {
-	struct timeval start_t, stop_t;
-	int			tmpfile, i;
-	char	   *full_buf = (char *) malloc(XLOG_SEG_SIZE),
-			   *buf, *filename = FSYNC_FILENAME;
+	handle_args(argc, argv);
+	
+	prepare_buf();
+
+	test_open();
+	
+	test_non_sync();
+	
+	/* Test using 1 8k write */
+	test_sync(1);
+
+	/* Test using 2 8k writes */
+	test_sync(2);
+	
+	test_open_syncs();
+
+	test_file_descriptor_sync();
+	
+	unlink(filename);
+
+	return 0;
+}
+
+void
+handle_args(int argc, char *argv[])
+{
+	if (argc > 1 && strcmp(argv[1], "-h") == 0)
+	{
+		fprintf(stderr, "test_fsync [-f filename] [ops-per-test]\n");
+		exit(1);
+	}
 	
 	/* 
-	 * arguments: loops and filename (optional) 
+	 * arguments: ops_per_test and filename (optional) 
 	 */
 	if (argc > 2 && strcmp(argv[1], "-f") == 0)
 	{
@@ -58,10 +97,27 @@ main(int argc, char *argv[])
 	}
 
 	if (argc > 1) 
-		loops = atoi(argv[1]);
+		ops_per_test = atoi(argv[1]);
+
+	printf("Ops-per-test = %d\n\n", ops_per_test);
+}
 
-	for (i = 0; i < XLOG_SEG_SIZE; i++)
-		full_buf[i] = random();
+void
+prepare_buf(void)
+{
+	int			ops;
+
+	/* write random data into buffer */
+	for (ops = 0; ops < XLOG_SEG_SIZE; ops++)
+		full_buf[ops] = random();
+
+	buf = (char *) TYPEALIGN(ALIGNOF_XLOG_BUFFER, full_buf);
+}
+
+void
+test_open(void)
+{
+	int			tmpfile;
 
 	/* 
 	 * test if we can open the target file 
@@ -70,25 +126,28 @@ main(int argc, char *argv[])
 		die("Cannot open output file.");
 	if (write(tmpfile, full_buf, XLOG_SEG_SIZE) != XLOG_SEG_SIZE)
 		die("write failed");
-	/*
-	 * fsync now so that dirty buffers don't skew later tests
-	 */
+
+	/* fsync now so that dirty buffers don't skew later tests */
 	if (fsync(tmpfile) != 0)
 		die("fsync failed");
-	close(tmpfile);
 
-	buf = (char *) TYPEALIGN(ALIGNOF_XLOG_BUFFER, full_buf);
+	close(tmpfile);
+}
 
-	printf("Loops = %d\n\n", loops);
+void
+test_non_sync(void)
+{
+	int			tmpfile, ops;
 
 	/*
 	 * Test a simple write without fsync
 	 */
-	printf("Simple write:\n");
+	printf("Simple non-sync'ed write:\n");
 	printf(LABEL_FORMAT, "8k write");
 	fflush(stdout);
+
 	gettimeofday(&start_t, NULL);
-	for (i = 0; i < loops; i++)
+	for (ops = 0; ops < ops_per_test; ops++)
 	{
 		if ((tmpfile = open(filename, O_RDWR, 0)) == -1)
 			die("Cannot open output file.");
@@ -98,23 +157,35 @@ main(int argc, char *argv[])
 	}
 	gettimeofday(&stop_t, NULL);
 	print_elapse(start_t, stop_t);
+}
 
-	/*
-	 * Test all fsync methods using single 8k writes
-	 */
+void
+test_sync(int writes_per_op)
+{
+	int			tmpfile, ops, writes;
+
+	if (writes_per_op == 1)
 		printf("\nCompare file sync methods using one write:\n");
+	else
+		printf("\nCompare file sync methods using two writes:\n");
+	printf("(in wal_sync_method preference order)\n");
 
 	/*
 	 * Test open_datasync if available
 	 */
 #ifdef OPEN_DATASYNC_FLAG
+	if (writes_per_op == 1)
 		printf(LABEL_FORMAT, "open_datasync 8k write");
+	else
+	 	printf(LABEL_FORMAT, "2 open_datasync 8k writes");
 	fflush(stdout);
+
 	if ((tmpfile = open(filename, O_RDWR | O_DSYNC, 0)) == -1)
 		die("Cannot open output file.");
 	gettimeofday(&start_t, NULL);
-	for (i = 0; i < loops; i++)
+	for (ops = 0; ops < ops_per_test; ops++)
 	{
+		for (writes = 0; writes < writes_per_op; writes++)
 			if (write(tmpfile, buf, WRITE_SIZE) != WRITE_SIZE)
 				die("write failed");
 		if (lseek(tmpfile, 0, SEEK_SET) == -1)
@@ -128,65 +199,20 @@ main(int argc, char *argv[])
 	 * If O_DIRECT is enabled, test that with open_datasync
 	 */
 #if PG_O_DIRECT != 0
-	fflush(stdout);
 	if ((tmpfile = open(filename, O_RDWR | O_DSYNC | PG_O_DIRECT, 0)) == -1)
 		printf(NA_FORMAT, "o_direct", "n/a on this filesystem\n");
 	else
 	{
+		if (writes_per_op == 1)
 			printf(LABEL_FORMAT, "open_datasync 8k direct I/O write");
-		gettimeofday(&start_t, NULL);
-		for (i = 0; i < loops; i++)
-		{
-			if (write(tmpfile, buf, WRITE_SIZE) != WRITE_SIZE)
-				die("write failed");
-			if (lseek(tmpfile, 0, SEEK_SET) == -1)
-				die("seek failed");
-		}
-		gettimeofday(&stop_t, NULL);
-		close(tmpfile);
-		print_elapse(start_t, stop_t);
-	}
-#else
-		printf(NA_FORMAT, "o_direct", "n/a\n");
-#endif
-
-#else
-	printf(NA_FORMAT, "open_datasync", "n/a\n");
-#endif
-
-/*
- * Test open_sync if available
- */
-#ifdef OPEN_SYNC_FLAG
-	printf(LABEL_FORMAT, "open_sync 8k write");
+		else
+			printf(LABEL_FORMAT, "2 open_datasync 8k direct I/O writes");
 		fflush(stdout);
-	if ((tmpfile = open(filename, O_RDWR | OPEN_SYNC_FLAG, 0)) == -1)
-		die("Cannot open output file.");
-	gettimeofday(&start_t, NULL);
-	for (i = 0; i < loops; i++)
-	{
-		if (write(tmpfile, buf, WRITE_SIZE) != WRITE_SIZE)
-			die("write failed");
-		if (lseek(tmpfile, 0, SEEK_SET) == -1)
-			die("seek failed");
-	}
-	gettimeofday(&stop_t, NULL);
-	close(tmpfile);
-	print_elapse(start_t, stop_t);
 
-	/*
-	 * If O_DIRECT is enabled, test that with open_sync
-	 */
-#if PG_O_DIRECT != 0
-	printf(LABEL_FORMAT, "open_sync 8k direct I/O write");
-	fflush(stdout);
-	if ((tmpfile = open(filename, O_RDWR | OPEN_SYNC_FLAG | PG_O_DIRECT, 0)) == -1)
-		printf(NA_FORMAT, "o_direct", "n/a on this filesystem\n");
-	else
-	{
 		gettimeofday(&start_t, NULL);
-		for (i = 0; i < loops; i++)
+		for (ops = 0; ops < ops_per_test; ops++)
 		{
+			for (writes = 0; writes < writes_per_op; writes++)
 				if (write(tmpfile, buf, WRITE_SIZE) != WRITE_SIZE)
 					die("write failed");
 			if (lseek(tmpfile, 0, SEEK_SET) == -1)
@@ -201,20 +227,25 @@ main(int argc, char *argv[])
 #endif
 
 #else
-	printf(NA_FORMAT, "open_sync", "n/a\n");
+	printf(NA_FORMAT, "open_datasync", "n/a\n");
 #endif
 
 /*
  * Test fdatasync if available
  */
 #ifdef HAVE_FDATASYNC
+	if (writes_per_op == 1)
 		printf(LABEL_FORMAT, "8k write, fdatasync");
+	else
+		printf(LABEL_FORMAT, "8k write, 8k write, fdatasync");
 	fflush(stdout);
+
 	if ((tmpfile = open(filename, O_RDWR, 0)) == -1)
 		die("Cannot open output file.");
 	gettimeofday(&start_t, NULL);
-	for (i = 0; i < loops; i++)
+	for (ops = 0; ops < ops_per_test; ops++)
 	{
+		for (writes = 0; writes < writes_per_op; writes++)
 			if (write(tmpfile, buf, WRITE_SIZE) != WRITE_SIZE)
 				die("write failed");
 		fdatasync(tmpfile);
@@ -231,13 +262,18 @@ main(int argc, char *argv[])
 /*
  * Test fsync
  */
+	if (writes_per_op == 1)
 		printf(LABEL_FORMAT, "8k write, fsync");
+	else
+		printf(LABEL_FORMAT, "8k write, 8k write, fsync");
 	fflush(stdout);
+
 	if ((tmpfile = open(filename, O_RDWR, 0)) == -1)
 		die("Cannot open output file.");
 	gettimeofday(&start_t, NULL);
-	for (i = 0; i < loops; i++)
+	for (ops = 0; ops < ops_per_test; ops++)
 	{
+		for (writes = 0; writes < writes_per_op; writes++)
 			if (write(tmpfile, buf, WRITE_SIZE) != WRITE_SIZE)
 				die("write failed");
 		if (fsync(tmpfile) != 0)
@@ -253,13 +289,18 @@ main(int argc, char *argv[])
  * If fsync_writethrough is available, test as well
  */	
 #ifdef HAVE_FSYNC_WRITETHROUGH
+	if (writes_per_op == 1)
 		printf(LABEL_FORMAT, "8k write, fsync_writethrough");
+	else
+		printf(LABEL_FORMAT, "8k write, 8k write, fsync_writethrough");
 	fflush(stdout);
+
 	if ((tmpfile = open(filename, O_RDWR, 0)) == -1)
 		die("Cannot open output file.");
 	gettimeofday(&start_t, NULL);
-	for (i = 0; i < loops; i++)
+	for (ops = 0; ops < ops_per_test; ops++)
 	{
+		for (writes = 0; writes < writes_per_op; writes++)
 			if (write(tmpfile, buf, WRITE_SIZE) != WRITE_SIZE)
 				die("write failed");
 		if (fcntl(tmpfile, F_FULLFSYNC ) != 0)
@@ -274,73 +315,22 @@ main(int argc, char *argv[])
 	printf(NA_FORMAT, "fsync_writethrough", "n/a\n");
 #endif
 
-	/*
-	 * Compare some of the file sync methods with 
-	 * two 8k writes to see if timing is different
-	 */
-	printf("\nCompare file sync methods using two writes:\n");
-
-/*
- * Test open_datasync with and without o_direct
- */
-#ifdef OPEN_DATASYNC_FLAG
- 	printf(LABEL_FORMAT, "2 open_datasync 8k writes");
-	fflush(stdout);
-	if ((tmpfile = open(filename, O_RDWR | O_DSYNC, 0)) == -1)
-		die("Cannot open output file.");
-	gettimeofday(&start_t, NULL);
-	for (i = 0; i < loops; i++)
-	{
-		if (write(tmpfile, buf, WRITE_SIZE) != WRITE_SIZE)
-			die("write failed");
-		if (write(tmpfile, buf, WRITE_SIZE) != WRITE_SIZE)
-			die("write failed");
-		if (lseek(tmpfile, 0, SEEK_SET) == -1)
-			die("seek failed");
-	}
-	gettimeofday(&stop_t, NULL);
-	close(tmpfile);
-	print_elapse(start_t, stop_t);
-	
-#if PG_O_DIRECT != 0
-	printf(LABEL_FORMAT, "2 open_datasync direct I/O 8k writes");
-	fflush(stdout);
-	if ((tmpfile = open(filename, O_RDWR | O_DSYNC | PG_O_DIRECT, 0)) == -1)
-		die("Cannot open output file.");
-	gettimeofday(&start_t, NULL);
-	for (i = 0; i < loops; i++)
-	{
-		if (write(tmpfile, buf, WRITE_SIZE) != WRITE_SIZE)
-			die("write failed");
-		if (write(tmpfile, buf, WRITE_SIZE) != WRITE_SIZE)
-			die("write failed");
-		if (lseek(tmpfile, 0, SEEK_SET) == -1)
-			die("seek failed");
-	}
-	gettimeofday(&stop_t, NULL);
-	close(tmpfile);
-	print_elapse(start_t, stop_t);
-#else
-		printf(NA_FORMAT, "o_direct" "n/a\n");
-#endif
-
-#else
-	printf(NA_FORMAT, "open_datasync", "n/a\n");
-#endif
-
 /*
- * Test open_sync with and without o_direct
+ * Test open_sync if available
  */
 #ifdef OPEN_SYNC_FLAG
+	if (writes_per_op == 1)
+		printf(LABEL_FORMAT, "open_sync 8k write");
+	else
 		printf(LABEL_FORMAT, "2 open_sync 8k writes");
 	fflush(stdout);
+
 	if ((tmpfile = open(filename, O_RDWR | OPEN_SYNC_FLAG, 0)) == -1)
 		die("Cannot open output file.");
 	gettimeofday(&start_t, NULL);
-	for (i = 0; i < loops; i++)
+	for (ops = 0; ops < ops_per_test; ops++)
 	{
-		if (write(tmpfile, buf, WRITE_SIZE) != WRITE_SIZE)
-			die("write failed");
+		for (writes = 0; writes < writes_per_op; writes++)
 			if (write(tmpfile, buf, WRITE_SIZE) != WRITE_SIZE)
 				die("write failed");
 		if (lseek(tmpfile, 0, SEEK_SET) == -1)
@@ -350,16 +340,24 @@ main(int argc, char *argv[])
 	close(tmpfile);
 	print_elapse(start_t, stop_t);
 
+	/*
+	 * If O_DIRECT is enabled, test that with open_sync
+	 */
 #if PG_O_DIRECT != 0
-	printf(LABEL_FORMAT, "2 open_sync direct I/O 8k writes");
+	if (writes_per_op == 1)
+		printf(LABEL_FORMAT, "open_sync 8k direct I/O write");
+	else
+		printf(LABEL_FORMAT, "2 open_sync 8k direct I/O writes");
 	fflush(stdout);
+
 	if ((tmpfile = open(filename, O_RDWR | OPEN_SYNC_FLAG | PG_O_DIRECT, 0)) == -1)
-		die("Cannot open output file.");
+		printf(NA_FORMAT, "o_direct", "n/a on this filesystem\n");
+	else
+	{
 		gettimeofday(&start_t, NULL);
-	for (i = 0; i < loops; i++)
+		for (ops = 0; ops < ops_per_test; ops++)
 		{
-		if (write(tmpfile, buf, WRITE_SIZE) != WRITE_SIZE)
-			die("write failed");
+			for (writes = 0; writes < writes_per_op; writes++)
 				if (write(tmpfile, buf, WRITE_SIZE) != WRITE_SIZE)
 					die("write failed");
 			if (lseek(tmpfile, 0, SEEK_SET) == -1)
@@ -368,6 +366,7 @@ main(int argc, char *argv[])
 		gettimeofday(&stop_t, NULL);
 		close(tmpfile);
 		print_elapse(start_t, stop_t);
+	}
 #else
 	printf(NA_FORMAT, "o_direct", "n/a\n");
 #endif
@@ -375,82 +374,12 @@ main(int argc, char *argv[])
 #else
 	printf(NA_FORMAT, "open_sync", "n/a\n");
 #endif
+}
 
-/*
- *	Test fdatasync
- */
-#ifdef HAVE_FDATASYNC
-	printf(LABEL_FORMAT, "8k write, 8k write, fdatasync");
-	fflush(stdout);
-	if ((tmpfile = open(filename, O_RDWR, 0)) == -1)
-		die("Cannot open output file.");
-	gettimeofday(&start_t, NULL);
-	for (i = 0; i < loops; i++)
-	{
-		if (write(tmpfile, buf, WRITE_SIZE) != WRITE_SIZE)
-			die("write failed");
-		if (write(tmpfile, buf, WRITE_SIZE) != WRITE_SIZE)
-			die("write failed");
-		fdatasync(tmpfile);
-		if (lseek(tmpfile, 0, SEEK_SET) == -1)
-			die("seek failed");
-	}
-	gettimeofday(&stop_t, NULL);
-	close(tmpfile);
-	print_elapse(start_t, stop_t);
-#else
-	printf(NA_FORMAT, "fdatasync", "n/a\n");
-#endif
-
-/*
- * Test basic fsync
- */
-	printf(LABEL_FORMAT, "8k write, 8k write, fsync");
-	fflush(stdout);
-	if ((tmpfile = open(filename, O_RDWR, 0)) == -1)
-		die("Cannot open output file.");
-	gettimeofday(&start_t, NULL);
-	for (i = 0; i < loops; i++)
-	{
-		if (write(tmpfile, buf, WRITE_SIZE) != WRITE_SIZE)
-			die("write failed");
-		if (write(tmpfile, buf, WRITE_SIZE) != WRITE_SIZE)
-			die("write failed");
-		if (fsync(tmpfile) != 0)
-			die("fsync failed");
-		if (lseek(tmpfile, 0, SEEK_SET) == -1)
-			die("seek failed");
-	}
-	gettimeofday(&stop_t, NULL);
-	close(tmpfile);
-	print_elapse(start_t, stop_t);
-	
-/*
- * Test fsync_writethrough if available
- */	
-#ifdef HAVE_FSYNC_WRITETHROUGH
-	printf(LABEL_FORMAT, "8k write, 8k write, fsync_writethrough");
-	fflush(stdout);
-	if ((tmpfile = open(filename, O_RDWR, 0)) == -1)
-		die("Cannot open output file.");
-	gettimeofday(&start_t, NULL);
-	for (i = 0; i < loops; i++)
-	{
-		if (write(tmpfile, buf, WRITE_SIZE) != WRITE_SIZE)
-			die("write failed");
-		if (write(tmpfile, buf, WRITE_SIZE) != WRITE_SIZE)
-			die("write failed");
-		if (fcntl(tmpfile, F_FULLFSYNC) != 0)
-			die("fsync failed");
-		if (lseek(tmpfile, 0, SEEK_SET) == -1)
-			die("seek failed");
-	}
-	gettimeofday(&stop_t, NULL);
-	close(tmpfile);
-	print_elapse(start_t, stop_t);
-#else
-	printf(NA_FORMAT, "fsync_writethrough", "n/a\n");
-#endif
+void
+test_open_syncs(void)
+{
+	int			tmpfile, ops;
 
 	/*
 	 * Compare 1 to 2 writes
@@ -465,10 +394,11 @@ main(int argc, char *argv[])
 #ifdef OPEN_SYNC_FLAG
 	printf(LABEL_FORMAT, "open_sync 16k write");
 	fflush(stdout);
+
 	if ((tmpfile = open(filename, O_RDWR | OPEN_SYNC_FLAG, 0)) == -1)
 		die("Cannot open output file.");
 	gettimeofday(&start_t, NULL);
-	for (i = 0; i < loops; i++)
+	for (ops = 0; ops < ops_per_test; ops++)
 	{
 		if (write(tmpfile, buf, WRITE_SIZE * 2) != WRITE_SIZE * 2)
 			die("write failed");
@@ -481,10 +411,11 @@ main(int argc, char *argv[])
 
 	printf(LABEL_FORMAT, "2 open_sync 8k writes");
 	fflush(stdout);
+
 	if ((tmpfile = open(filename, O_RDWR | OPEN_SYNC_FLAG, 0)) == -1)
 		die("Cannot open output file.");
 	gettimeofday(&start_t, NULL);
-	for (i = 0; i < loops; i++)
+	for (ops = 0; ops < ops_per_test; ops++)
 	{
 		if (write(tmpfile, buf, WRITE_SIZE) != WRITE_SIZE)
 			die("write failed");
@@ -499,6 +430,12 @@ main(int argc, char *argv[])
 #else
 	printf(NA_FORMAT, "open_sync", "n/a\n");
 #endif
+}
+
+void
+test_file_descriptor_sync(void)
+{
+	int			tmpfile, ops;
 
 	/*
 	 * Test whether fsync can sync data written on a different
@@ -517,8 +454,9 @@ main(int argc, char *argv[])
 	 */
 	printf(LABEL_FORMAT, "8k write, fsync, close");
 	fflush(stdout);
+
 	gettimeofday(&start_t, NULL);
-	for (i = 0; i < loops; i++)
+	for (ops = 0; ops < ops_per_test; ops++)
 	{
 		if ((tmpfile = open(filename, O_RDWR, 0)) == -1)
 			die("Cannot open output file.");
@@ -545,8 +483,9 @@ main(int argc, char *argv[])
 	 */
  	printf(LABEL_FORMAT, "8k write, close, fsync");
  	fflush(stdout);
+
 	gettimeofday(&start_t, NULL);
-	for (i = 0; i < loops; i++)
+	for (ops = 0; ops < ops_per_test; ops++)
 	{
 		if ((tmpfile = open(filename, O_RDWR, 0)) == -1)
 			die("Cannot open output file.");
@@ -563,13 +502,6 @@ main(int argc, char *argv[])
 	gettimeofday(&stop_t, NULL);
 	print_elapse(start_t, stop_t);
 
-	/* 
-	 * cleanup 
-	 */
-	free(full_buf);
-	unlink(filename);
-
-	return 0;
 }
 
 /* 
@@ -580,7 +512,7 @@ print_elapse(struct timeval start_t, struct timeval stop_t)
 {
 	double		total_time = (stop_t.tv_sec - start_t.tv_sec) +
 	(stop_t.tv_usec - start_t.tv_usec) * 0.000001;
-	double		per_second = loops / total_time;
+	double		per_second = ops_per_test / total_time;
 
 	printf("%9.3f ops/sec\n", per_second);
 }