Adjust test_fsync code to be more sane.

Backpatch to 8.4.X.

diff --git a/src/tools/fsync/test_fsync.c b/src/tools/fsync/test_fsync.c
index b87237a689d26aaf9b33abb3ae7be3f11f8dc81b..6b3e939cd4ea6a926a0683bddee7ba0c826bb2b0 100644 (file)
--- a/src/tools/fsync/test_fsync.c
+++ b/src/tools/fsync/test_fsync.c
@@ -1,5 +1,5 @@
 /*
- * $PostgreSQL: pgsql/src/tools/fsync/test_fsync.c,v 1.23 2009/06/11 14:49:15 momjian Exp $
+ * $PostgreSQL: pgsql/src/tools/fsync/test_fsync.c,v 1.24 2009/08/10 18:19:06 momjian Exp $
  *
  *
  * test_fsync.c
@@ -30,7 +30,7 @@
 #define FSYNC_FILENAME "/var/tmp/test_fsync.out"
 #endif
 
-#define WRITE_SIZE (16 * 1024)
+#define WRITE_SIZE (16 * 1024) /* 16k */
 
 void       die(char *str);
 void       print_elapse(struct timeval start_t, struct timeval elapse_t);
@@ -71,6 +71,9 @@ main(int argc, char *argv[])
 
    buf = (char *) TYPEALIGN(ALIGNOF_XLOG_BUFFER, full_buf);
 
+   /*
+    *  Simple write
+    */
    printf("Simple write timing:\n");
    /* write only */
    gettimeofday(&start_t, NULL);
@@ -87,8 +90,11 @@ main(int argc, char *argv[])
    print_elapse(start_t, elapse_t);
    printf("\n");
 
+   /*
+    *  Fsync another file descriptor?
+    */
    printf("\nCompare fsync times on write() and non-write() descriptor:\n");
-   printf("(If the times are similar, fsync() can sync data written\n on a different descriptor.)\n");
+   printf("If the times are similar, fsync() can sync data written\non a different descriptor.\n");
 
    /* write, fsync, close */
    gettimeofday(&start_t, NULL);
@@ -132,6 +138,9 @@ main(int argc, char *argv[])
    print_elapse(start_t, elapse_t);
    printf("\n");
 
+   /*
+    *  Compare 1 to 2 writes
+    */
    printf("\nCompare one o_sync write to two:\n");
 
 #ifdef OPEN_SYNC_FLAG
@@ -148,7 +157,7 @@ main(int argc, char *argv[])
    print_elapse(start_t, elapse_t);
    printf("\n");
 
-   /* 2*8k o_sync writes */
+   /* Two 8k o_sync writes */
    if ((tmpfile = open(filename, O_RDWR | OPEN_SYNC_FLAG, 0)) == -1)
        die("Cannot open output file.");
    gettimeofday(&start_t, NULL);
@@ -163,14 +172,16 @@ main(int argc, char *argv[])
    close(tmpfile);
    printf("\ttwo 8k o_sync writes   ");
    print_elapse(start_t, elapse_t);
-   printf("\n");
-
-   printf("\nCompare file sync methods with one 8k write:\n");
 #else
    printf("\t(o_sync unavailable)  ");
 #endif
    printf("\n");
 
+   /*
+    *  Compare file sync methods with one 8k write
+    */
+   printf("\nCompare file sync methods with one 8k write:\n");
+
 #ifdef OPEN_DATASYNC_FLAG
    /* open_dsync, write */
    if ((tmpfile = open(filename, O_RDWR | O_DSYNC, 0)) == -1)
@@ -183,7 +194,11 @@ main(int argc, char *argv[])
    close(tmpfile);
    printf("\topen o_dsync, write    ");
    print_elapse(start_t, elapse_t);
+#else
+   printf("\t(o_dsync unavailable)  ");
+#endif
    printf("\n");
+
 #ifdef OPEN_SYNC_FLAG
    /* open_fsync, write */
    if ((tmpfile = open(filename, O_RDWR | OPEN_SYNC_FLAG, 0)) == -1)
@@ -196,9 +211,8 @@ main(int argc, char *argv[])
    close(tmpfile);
    printf("\topen o_sync, write     ");
    print_elapse(start_t, elapse_t);
-#endif
 #else
-   printf("\t(o_dsync unavailable)  ");
+   printf("\t(o_sync unavailable)  ");
 #endif
    printf("\n");
 
@@ -235,11 +249,14 @@ main(int argc, char *argv[])
    }
    gettimeofday(&elapse_t, NULL);
    close(tmpfile);
-   printf("\twrite, fsync,          ");
+   printf("\twrite, fsync           ");
    print_elapse(start_t, elapse_t);
    printf("\n");
 
-   printf("\nCompare file sync methods with 2 8k writes:\n");
+   /*
+    *  Compare file sync methods with two 8k write
+    */
+   printf("\nCompare file sync methods with two 8k writes:\n");
 
 #ifdef OPEN_DATASYNC_FLAG
    /* open_dsync, write */
@@ -318,7 +335,7 @@ main(int argc, char *argv[])
    }
    gettimeofday(&elapse_t, NULL);
    close(tmpfile);
-   printf("\twrite, fsync,          ");
+   printf("\twrite, fsync           ");
    print_elapse(start_t, elapse_t);
    printf("\n");