Switch pg_test_fsync to use binary mode on Windows

pg_test_fsync has always opened files using the text mode on Windows, as
this is the default mode used if not enforced by _setmode().

This fixes a failure when running pg_test_fsync down to 12 because
O_DSYNC and the text mode are not able to work together nicely.  We
fixed the handling of O_DSYNC in 12~ for the tool by switching to the
concurrent-safe version of fopen() in src/port/ with 0ba06e0.  And
40cfe86, by enforcing the text mode for compatibility reasons if O_TEXT
or O_BINARY are not specified by the caller, broke pg_test_fsync.  For
all versions, this avoids any translation overhead, and pg_test_fsync
should test binary writes, so it is a gain in all cases.

Note that O_DSYNC is still not handled correctly in ~11, leading to
pg_test_fsync to show insanely high numbers for open_datasync() (using
this property it is easy to notice that the binary mode is much
faster).  This would require a backpatch of 0ba06e0 and 40cfe86, which
could potentially break existing applications, so this is left out.

There are no TAP tests for this tool yet, so I have checked all builds
manually using MSVC.  We could invent a new option to run a single
transaction instead of using a duration of 1s to make the tests a
maximum short, but this is left as future work.

Thanks to Bruce Momjian for the discussion.

Reported-by: Jeff Janes
Author: Michael Paquier
Discussion: https://postgr.es/m/16526-279ded30a230d275@postgresql.org
Backpatch-through: 9.5

diff --git a/src/bin/pg_test_fsync/pg_test_fsync.c b/src/bin/pg_test_fsync/pg_test_fsync.c
index 2ca1608bd215d5178ec86b7adf41c70bffb81fb0..6e4729312331849fd8145e6234e4f2704ce58414 100644 (file)
--- a/src/bin/pg_test_fsync/pg_test_fsync.c
+++ b/src/bin/pg_test_fsync/pg_test_fsync.c
@@ -224,7 +224,7 @@ test_open(void)
    /*
     * test if we can open the target file
     */
-   if ((tmpfile = open(filename, O_RDWR | O_CREAT, S_IRUSR | S_IWUSR)) == -1)
+   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) !=
@@ -259,7 +259,7 @@ test_sync(int writes_per_op)
    fflush(stdout);
 
 #ifdef OPEN_DATASYNC_FLAG
-   if ((tmpfile = open(filename, O_RDWR | O_DSYNC | PG_O_DIRECT, 0)) == -1)
+   if ((tmpfile = open(filename, O_RDWR | O_DSYNC | PG_O_DIRECT | PG_BINARY, 0)) == -1)
    {
        printf(NA_FORMAT, _("n/a*"));
        fs_warning = true;
@@ -289,7 +289,7 @@ test_sync(int writes_per_op)
    fflush(stdout);
 
 #ifdef HAVE_FDATASYNC
-   if ((tmpfile = open(filename, O_RDWR, 0)) == -1)
+   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++)
@@ -313,7 +313,7 @@ test_sync(int writes_per_op)
    printf(LABEL_FORMAT, "fsync");
    fflush(stdout);
 
-   if ((tmpfile = open(filename, O_RDWR, 0)) == -1)
+   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++)
@@ -336,7 +336,7 @@ test_sync(int writes_per_op)
    fflush(stdout);
 
 #ifdef HAVE_FSYNC_WRITETHROUGH
-   if ((tmpfile = open(filename, O_RDWR, 0)) == -1)
+   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++)
@@ -362,7 +362,7 @@ test_sync(int writes_per_op)
    fflush(stdout);
 
 #ifdef OPEN_SYNC_FLAG
-   if ((tmpfile = open(filename, O_RDWR | OPEN_SYNC_FLAG | PG_O_DIRECT, 0)) == -1)
+   if ((tmpfile = open(filename, O_RDWR | OPEN_SYNC_FLAG | PG_O_DIRECT | PG_BINARY, 0)) == -1)
    {
        printf(NA_FORMAT, _("n/a*"));
        fs_warning = true;
@@ -429,7 +429,7 @@ test_open_sync(const char *msg, int writes_size)
    fflush(stdout);
 
 #ifdef OPEN_SYNC_FLAG
-   if ((tmpfile = open(filename, O_RDWR | OPEN_SYNC_FLAG | PG_O_DIRECT, 0)) == -1)
+   if ((tmpfile = open(filename, O_RDWR | OPEN_SYNC_FLAG | PG_O_DIRECT | PG_BINARY, 0)) == -1)
        printf(NA_FORMAT, _("n/a*"));
    else
    {
@@ -477,7 +477,7 @@ test_file_descriptor_sync(void)
    START_TIMER;
    for (ops = 0; alarm_triggered == false; ops++)
    {
-       if ((tmpfile = open(filename, O_RDWR, 0)) == -1)
+       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");
@@ -489,7 +489,7 @@ test_file_descriptor_sync(void)
         * open and close the file again to be consistent with the following
         * test
         */
-       if ((tmpfile = open(filename, O_RDWR, 0)) == -1)
+       if ((tmpfile = open(filename, O_RDWR | PG_BINARY, 0)) == -1)
            die("could not open output file");
        close(tmpfile);
    }
@@ -505,13 +505,13 @@ test_file_descriptor_sync(void)
    START_TIMER;
    for (ops = 0; alarm_triggered == false; ops++)
    {
-       if ((tmpfile = open(filename, O_RDWR, 0)) == -1)
+       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, 0)) == -1)
+       if ((tmpfile = open(filename, O_RDWR | PG_BINARY, 0)) == -1)
            die("could not open output file");
        if (fsync(tmpfile) != 0)
            die("fsync failed");
@@ -536,7 +536,7 @@ test_non_sync(void)
    START_TIMER;
    for (ops = 0; alarm_triggered == false; ops++)
    {
-       if ((tmpfile = open(filename, O_RDWR, 0)) == -1)
+       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");