From 215cbc90f8db3fc8a70af5572b156f49216c2f70 Mon Sep 17 00:00:00 2001
From: Magnus Hagander <magnus@hagander.net>
Date: Tue, 16 Feb 2010 19:26:02 +0000
Subject: [PATCH] Add emulation of non-blocking sockets to the win32
socket/signal layer, and use this in pq_getbyte_if_available.
It's only a limited implementation which swithes the whole emulation layer
no non-blocking mode, but that's enough as long as non-blocking is only
used during a short period of time, and only one socket is accessed during
this time.
---
src/backend/libpq/pqcomm.c | 14 +++++++++++++-
src/backend/port/win32/socket.c | 25 ++++++++++++++++++++++++-
src/include/port/win32.h | 4 +++-
3 files changed, 40 insertions(+), 3 deletions(-)
diff --git a/src/backend/libpq/pqcomm.c b/src/backend/libpq/pqcomm.c
index f4e69742524..8f40c93d892 100644
--- a/src/backend/libpq/pqcomm.c
+++ b/src/backend/libpq/pqcomm.c
@@ -30,7 +30,7 @@
* Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/backend/libpq/pqcomm.c,v 1.202 2010/01/15 09:19:02 heikki Exp $
+ * $PostgreSQL: pgsql/src/backend/libpq/pqcomm.c,v 1.203 2010/02/16 19:26:02 mha Exp $
*
*-------------------------------------------------------------------------
*/
@@ -837,9 +837,13 @@ pq_getbyte_if_available(unsigned char *c)
}
/* Temporarily put the socket into non-blocking mode */
+#ifdef WIN32
+ pgwin32_noblock = 1;
+#else
if (!pg_set_noblock(MyProcPort->sock))
ereport(ERROR,
(errmsg("couldn't put socket to non-blocking mode: %m")));
+#endif
MyProcPort->noblock = true;
PG_TRY();
{
@@ -851,16 +855,24 @@ pq_getbyte_if_available(unsigned char *c)
* The rest of the backend code assumes the socket is in blocking
* mode, so treat failure as FATAL.
*/
+#ifdef WIN32
+ pgwin32_noblock = 0;
+#else
if (!pg_set_block(MyProcPort->sock))
ereport(FATAL,
(errmsg("couldn't put socket to blocking mode: %m")));
+#endif
MyProcPort->noblock = false;
PG_RE_THROW();
}
PG_END_TRY();
+#ifdef WIN32
+ pgwin32_noblock = 0;
+#else
if (!pg_set_block(MyProcPort->sock))
ereport(FATAL,
(errmsg("couldn't put socket to blocking mode: %m")));
+#endif
MyProcPort->noblock = false;
return r;
diff --git a/src/backend/port/win32/socket.c b/src/backend/port/win32/socket.c
index 8076b8caef5..af42576cab5 100644
--- a/src/backend/port/win32/socket.c
+++ b/src/backend/port/win32/socket.c
@@ -6,13 +6,26 @@
* Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/port/win32/socket.c,v 1.23 2010/01/02 16:57:50 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/port/win32/socket.c,v 1.24 2010/02/16 19:26:02 mha Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
+/*
+ * Indicate if pgwin32_recv() should operate in non-blocking mode.
+ *
+ * Since the socket emulation layer always sets the actual socket to
+ * non-blocking mode in order to be able to deliver signals, we must
+ * specify this in a separate flag if we actually need non-blocking
+ * operation.
+ *
+ * This flag changes the behaviour *globally* for all socket operations,
+ * so it should only be set for very short periods of time.
+ */
+int pgwin32_noblock = 0;
+
#undef socket
#undef accept
#undef connect
@@ -310,6 +323,16 @@ pgwin32_recv(SOCKET s, char *buf, int len, int f)
return -1;
}
+ if (pgwin32_noblock)
+ {
+ /*
+ * No data received, and we are in "emulated non-blocking mode", so return
+ * indicating thta we'd block if we were to continue.
+ */
+ errno = EWOULDBLOCK;
+ return -1;
+ }
+
/* No error, zero bytes (win2000+) or error+WSAEWOULDBLOCK (<=nt4) */
for (n = 0; n < 5; n++)
diff --git a/src/include/port/win32.h b/src/include/port/win32.h
index 3ec81c4f7ed..6dbda80f4fb 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 1.92 2010/02/13 02:34:14 tgl Exp $ */
+/* $PostgreSQL: pgsql/src/include/port/win32.h,v 1.93 2010/02/16 19:26:02 mha Exp $ */
#if defined(_MSC_VER) || defined(__BORLANDC__)
#define WIN32_ONLY_COMPILER
@@ -283,6 +283,8 @@ int pgwin32_send(SOCKET s, char *buf, int len, int flags);
const char *pgwin32_socket_strerror(int err);
int pgwin32_waitforsinglesocket(SOCKET s, int what, int timeout);
+extern int pgwin32_noblock;
+
/* in backend/port/win32/security.c */
extern int pgwin32_is_admin(void);
extern int pgwin32_is_service(void);
--
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