From b1f57d88f56e0fbb49e4e5c8839cd3fb3a580a14 Mon Sep 17 00:00:00 2001
From: Bruce Momjian <bruce@momjian.us>
Date: Thu, 24 Mar 2005 04:36:20 +0000
Subject: [PATCH] Change Win32 O_SYNC method to O_DSYNC because that is what
the method currently does. This is now the default Win32 wal sync method
because we perfer o_datasync to fsync.
Also, change Win32 fsync to a new wal sync method called
fsync_writethrough because that is the behavior of _commit, which is
what is used for fsync on Win32.
Backpatch to 8.0.X.
---
doc/src/sgml/runtime.sgml | 3 ++-
src/backend/access/transam/xlog.c | 18 ++++++++++++++++--
src/backend/utils/misc/postgresql.conf.sample | 3 ++-
src/include/port/win32.h | 5 +++--
src/port/open.c | 6 +++---
5 files changed, 26 insertions(+), 9 deletions(-)
diff --git a/doc/src/sgml/runtime.sgml b/doc/src/sgml/runtime.sgml
index 33c661dd5cb..408418ee33a 100644
--- a/doc/src/sgml/runtime.sgml
+++ b/doc/src/sgml/runtime.sgml
@@ -1,5 +1,5 @@
<!--
-$PostgreSQL: pgsql/doc/src/sgml/runtime.sgml,v 1.310 2005/03/19 23:27:04 tgl Exp $
+$PostgreSQL: pgsql/doc/src/sgml/runtime.sgml,v 1.311 2005/03/24 04:36:17 momjian Exp $
-->
<chapter Id="runtime">
@@ -1587,6 +1587,7 @@ SET ENABLE_SEQSCAN TO OFF;
values are
<literal>fsync</> (call <function>fsync()</> at each commit),
<literal>fdatasync</> (call <function>fdatasync()</> at each commit),
+ <literal>fsync_writethrough</> (call <function>_commit()</> at each commit on Windows),
<literal>open_sync</> (write WAL files with <function>open()</> option <symbol>O_SYNC</>), and
<literal>open_datasync</> (write WAL files with <function>open()</> option <symbol>O_DSYNC</>).
Not all of these choices are available on all platforms.
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 1a5772798b7..6bc5b78780c 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/backend/access/transam/xlog.c,v 1.181 2005/02/12 23:53:37 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/access/transam/xlog.c,v 1.182 2005/03/24 04:36:17 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@@ -63,8 +63,13 @@
#endif
#endif
+#if defined(O_DSYNC)
#if defined(OPEN_SYNC_FLAG)
-#if defined(O_DSYNC) && (O_DSYNC != OPEN_SYNC_FLAG)
+#if O_DSYNC != OPEN_SYNC_FLAG
+#define OPEN_DATASYNC_FLAG O_DSYNC
+#endif
+#else /* !defined(OPEN_SYNC_FLAG) */
+/* Win32 only has O_DSYNC */
#define OPEN_DATASYNC_FLAG O_DSYNC
#endif
#endif
@@ -79,7 +84,11 @@
#define DEFAULT_SYNC_METHOD SYNC_METHOD_FDATASYNC
#define DEFAULT_SYNC_FLAGBIT 0
#else
+#ifndef FSYNC_IS_WRITE_THROUGH
#define DEFAULT_SYNC_METHOD_STR "fsync"
+#else
+#define DEFAULT_SYNC_METHOD_STR "fsync_writethrough"
+#endif
#define DEFAULT_SYNC_METHOD SYNC_METHOD_FSYNC
#define DEFAULT_SYNC_FLAGBIT 0
#endif
@@ -5154,7 +5163,12 @@ assign_xlog_sync_method(const char *method, bool doit, GucSource source)
int new_sync_method;
int new_sync_bit;
+#ifndef FSYNC_IS_WRITE_THROUGH
if (pg_strcasecmp(method, "fsync") == 0)
+#else
+ /* Win32 fsync() == _commit(0, which writes through a write cache */
+ if (pg_strcasecmp(method, "fsync_writethrough") == 0)
+#endif
{
new_sync_method = SYNC_METHOD_FSYNC;
new_sync_bit = 0;
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index b68cd2f8cf9..113021fd79f 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -114,7 +114,8 @@
#fsync = true # turns forced synchronization on or off
#wal_sync_method = fsync # the default varies across platforms:
- # fsync, fdatasync, open_sync, or open_datasync
+ # fsync, fdatasync, fsync_writethrough,
+ # open_sync, open_datasync
#wal_buffers = 8 # min 4, 8KB each
#commit_delay = 0 # range 0-100000, in microseconds
#commit_siblings = 5 # range 1-1000
diff --git a/src/include/port/win32.h b/src/include/port/win32.h
index c3c7da737bc..de2483add01 100644
--- a/src/include/port/win32.h
+++ b/src/include/port/win32.h
@@ -1,4 +1,4 @@
-/* $PostgreSQL: pgsql/src/include/port/win32.h,v 1.43 2005/02/27 00:53:29 momjian Exp $ */
+/* $PostgreSQL: pgsql/src/include/port/win32.h,v 1.44 2005/03/24 04:36:19 momjian Exp $ */
/* undefine and redefine after #include */
#undef mkdir
@@ -17,6 +17,7 @@
#define fsync(a) _commit(a)
+#define FSYNC_IS_WRITE_THROUGH
#define ftruncate(a,b) chsize(a,b)
#define USES_WINSOCK
@@ -189,7 +190,7 @@ typedef int pid_t;
* to ensure that we don't collide with a future definition. It means
* we cannot use _O_NOINHERIT ourselves.
*/
-#define O_SYNC 0x0080
+#define O_DSYNC 0x0080
/*
* Supplement to <errno.h>.
diff --git a/src/port/open.c b/src/port/open.c
index cd17f4164f4..6e1d37d3cba 100644
--- a/src/port/open.c
+++ b/src/port/open.c
@@ -6,7 +6,7 @@
*
* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
*
- * $PostgreSQL: pgsql/src/port/open.c,v 1.8 2005/02/27 00:53:29 momjian Exp $
+ * $PostgreSQL: pgsql/src/port/open.c,v 1.9 2005/03/24 04:36:20 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@@ -63,7 +63,7 @@ win32_open(const char *fileName, int fileFlags,...)
/* Check that we can handle the request */
assert((fileFlags & ((O_RDONLY | O_WRONLY | O_RDWR) | O_APPEND |
(O_RANDOM | O_SEQUENTIAL | O_TEMPORARY) |
- _O_SHORT_LIVED | O_SYNC |
+ _O_SHORT_LIVED | O_DSYNC |
(O_CREAT | O_TRUNC | O_EXCL) | (O_TEXT | O_BINARY))) == fileFlags);
sa.nLength = sizeof(sa);
@@ -83,7 +83,7 @@ win32_open(const char *fileName, int fileFlags,...)
((fileFlags & O_SEQUENTIAL) ? FILE_FLAG_SEQUENTIAL_SCAN : 0) |
((fileFlags & _O_SHORT_LIVED) ? FILE_ATTRIBUTE_TEMPORARY : 0) |
((fileFlags & O_TEMPORARY) ? FILE_FLAG_DELETE_ON_CLOSE : 0)|
- ((fileFlags & O_SYNC) ? FILE_FLAG_WRITE_THROUGH : 0),
+ ((fileFlags & O_DSYNC) ? FILE_FLAG_WRITE_THROUGH : 0),
NULL)) == INVALID_HANDLE_VALUE)
{
switch (GetLastError())
--
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