WINCE: Add workaround for memory management problem on Windows CE < 6.0

This fixes the "32MB memory limit per process" problem in Windows CE < 6.0

3 files changed, 61 insertions, 8 deletions

diff --git a/backends/platform/wince/README-WinCE.txt b/backends/platform/wince/README-WinCE.txt
index 60bcf710bb..429168c293 100644
--- a/backends/platform/wince/README-WinCE.txt
+++ b/backends/platform/wince/README-WinCE.txt
@@ -1,18 +1,23 @@
 ScummVM Windows CE FAQ
-Last updated: 2011-07-20
-Release version: x.x.x
+Last updated: 2011-10-15
+Release version: 1.4.0
 ------------------------------------------------------------------------
 
 New in this version
 -------------------
-x.x.x:
-- Changed default values for "high_sample_rate" & "FM_high_quality" to "true" as
-  most devices today are fast enough to handle this. It's still possible to set
-  this to "false" if you have a slower device.
+1.4.0:
+- Changed the memory management so that it is finally possible to break the
+  32MB per process barrier on Windows CE. It should be possible now (finally)
+  to play nearly every game with the "big" binary (scummvm.exe, which includes
+  all game engines).
+- Changed default values for "high_sample_rate" & "FM_high_quality" to "true"
+  as most devices today are fast enough to handle this. It's still possible to
+  set this to "false" if you have a slower device.
 - Fix for TeenAgent & Hugo engines (both weren't running at all, crashed right
   at the beginning)
-- Replaced the game mass-adding functionality with the functionality used on all
-  other platforms. It now shows progress while searching for games.
+- Discworld 2 is now playable (works now because of the new memory management)
+- Replaced the game mass-adding functionality with the functionality used on
+  all other platforms. It now shows progress while searching for games.
 
 1.3.1:
 - Fix for Normal2xAspect scaler which was causing screen update issues in some
diff --git a/backends/platform/wince/wince-sdl.cpp b/backends/platform/wince/wince-sdl.cpp
index 1abc3cb350..4e17827e5c 100644
--- a/backends/platform/wince/wince-sdl.cpp
+++ b/backends/platform/wince/wince-sdl.cpp
@@ -72,6 +72,50 @@
 extern "C" _CRTIMP FILE *__cdecl   _wfreopen(const wchar_t *, const wchar_t *, FILE *);
 #endif
 
+#ifdef WRAP_MALLOC
+
+extern "C" void *__real_malloc(size_t size);
+extern "C" void __real_free(void *ptr);
+
+extern "C" void *__wrap_malloc(size_t size) {
+/*
+	void *ptr = __real_malloc(size);
+	printf("malloc(%d) = %p\n", size, ptr);
+	return ptr;
+*/
+	if (size < 64 * 1024) {
+		void *ptr = __real_malloc(size+4);
+//		printf("malloc(%d) = %p\n", size, ptr);
+		if (ptr != NULL) {
+			*((HANDLE*)ptr) = 0;
+			return 4+(char*)ptr;
+		}
+		return NULL;
+	}
+	HANDLE H = CreateFileMapping((HANDLE)INVALID_HANDLE_VALUE, 0, PAGE_READWRITE, 0, size+4, 0);
+	void *ptr = MapViewOfFile(H, FILE_MAP_ALL_ACCESS, 0, 0, 0);
+	*((HANDLE*)ptr) = H;
+	return 4+(char*)ptr;
+}
+
+extern "C" void __wrap_free(void *ptr) {
+/*
+	__real_free(ptr);
+	printf("free(%p)\n", ptr);
+*/
+	if (ptr != NULL) {
+		HANDLE H = *(HANDLE*)((char *)ptr-4);
+		if (H == 0) {
+			__real_free((char*)ptr-4);
+			return;
+		}
+		UnmapViewOfFile((char *)ptr-4);
+		CloseHandle(H);
+	}
+}
+
+#endif
+
 using namespace CEGUI;
 
 // ********************************************************************************************
diff --git a/backends/platform/wince/wince.mk b/backends/platform/wince/wince.mk
index cac3ad4e8f..c5f3274747 100644
--- a/backends/platform/wince/wince.mk
+++ b/backends/platform/wince/wince.mk
@@ -1,3 +1,7 @@
+ifdef WRAP_MALLOC
+	LDFLAGS += -Wl,--wrap,malloc -Wl,--wrap,free
+endif
+
 backends/platform/wince/PocketSCUMM.o: $(srcdir)/backends/platform/wince/PocketSCUMM.rc
 	$(QUIET)$(MKDIR) $(*D)
 	$(WINDRES) $(WINDRESFLAGS) -I$(srcdir)/backends/platform/wince $< $@