From 811be893fa743ef553950a5d31b7e68230d3cf11 Mon Sep 17 00:00:00 2001
From: Magnus Hagander <magnus@hagander.net>
Date: Mon, 29 Oct 2007 12:35:41 +0000
Subject: [PATCH] Add compat file for dynamically loading the functions that
 MinGW is missing the imports for. Add RegisterWaitForSingleObject() to the
 list of such functions, which should take care of the current buildfarm
 breakage.

---
 src/backend/port/win32/Makefile      |  4 +-
 src/backend/port/win32/mingwcompat.c | 77 ++++++++++++++++++++++++++++++++++++
 2 files changed, 79 insertions(+), 2 deletions(-)
 create mode 100644 src/backend/port/win32/mingwcompat.c

diff --git a/src/backend/port/win32/Makefile b/src/backend/port/win32/Makefile
index 620d921edd..6aabc21239 100644
--- a/src/backend/port/win32/Makefile
+++ b/src/backend/port/win32/Makefile
@@ -4,7 +4,7 @@
 #    Makefile for backend/port/win32
 #
 # IDENTIFICATION
-#    $PostgreSQL: pgsql/src/backend/port/win32/Makefile,v 1.10 2007/03/21 14:39:23 mha Exp $
+#    $PostgreSQL: pgsql/src/backend/port/win32/Makefile,v 1.11 2007/10/29 12:35:41 mha Exp $
 #
 #-------------------------------------------------------------------------
 
@@ -12,7 +12,7 @@ subdir = src/backend/port/win32
 top_builddir = ../../../..
 include $(top_builddir)/src/Makefile.global
 
-OBJS = timer.o socket.o signal.o security.o
+OBJS = timer.o socket.o signal.o security.o mingwcompat.o
 
 all: SUBSYS.o
 
diff --git a/src/backend/port/win32/mingwcompat.c b/src/backend/port/win32/mingwcompat.c
new file mode 100644
index 0000000000..da45854ef9
--- /dev/null
+++ b/src/backend/port/win32/mingwcompat.c
@@ -0,0 +1,77 @@
+/*-------------------------------------------------------------------------
+ *
+ * mingwcompat.c
+ *	  MinGW compatibility functions
+ *
+ * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *	  $PostgreSQL: pgsql/src/backend/port/win32/mingwcompat.c,v 1.1 2007/10/29 12:35:41 mha Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+/*
+ * This file contains loaders for functions that are missing in the MinGW 
+ * import libraries. It's only for actual Win32 API functions, so they are
+ * all present in proper Win32 compilers.
+ */
+#ifndef WIN32_ONLY_COMPILER
+
+static HMODULE kernel32 = NULL;
+
+/*
+ * Load DLL file just once regardless of how many functions
+ * we load/call in it.
+ */
+static void
+LoadKernel32()
+{
+	if (kernel32 != NULL)
+		return;
+
+	kernel32 = LoadLibraryEx("kernel32.dll", NULL, 0);
+	if (kernel32 == NULL)
+		ereport(FATAL,
+				(errmsg_internal("could not load kernel32.dll: %d",
+								 (int)GetLastError())));
+}
+
+
+/*
+ * Replacement for RegisterWaitForSingleObject(), which lives in
+ * kernel32.dll·
+ */
+typedef BOOL (WINAPI * __RegisterWaitForSingleObject)
+	(PHANDLE, HANDLE, WAITORTIMERCALLBACK, PVOID, ULONG, ULONG);
+__RegisterWaitForSingleObject _RegisterWaitForSingleObject = NULL;
+
+BOOL WINAPI 
+RegisterWaitForSingleObject(PHANDLE phNewWaitObject,
+							HANDLE hObject,
+							WAITORTIMERCALLBACK Callback,
+							PVOID Context,
+							ULONG dwMilliseconds,
+							ULONG dwFlags)
+{
+	if (_RegisterWaitForSingleObject == NULL)
+	{
+		LoadKernel32();
+
+		_RegisterWaitForSingleObject = (__RegisterWaitForSingleObject)
+			GetProcAddress(kernel32, "RegisterWaitForSingleObject");
+
+		if (_RegisterWaitForSingleObject == NULL)
+			ereport(FATAL,
+					(errmsg_internal("could not locate RegisterWaitForSingleObject in kernel32.dll: %d",
+									 (int)GetLastError())));
+	}
+
+	return (_RegisterWaitForSingleObject)
+		(phNewWaitObject, hObject, Callback, Context, dwMilliseconds, dwFlags);
+}
+
+#endif
+
-- 
2.11.0