[resend] wined3d: Make CreateFakeGLContext thread safe.

[Jan Zerebecki]

This adds thread safety to CreateFakeGLContext and it's
corresponding Release function only. This addresses no thread
safety in the rest of wined3d, which AFAIk as a whole is still
not thread safe. When addressing thread safety in wined3d it must
also be taken care that a GL context is not deleted away by a
different thread when execution is between these two functions.

If this patch is rejected from inclusion, please tell me why, as
I would have to ask anyway.

From: Jan Zerebecki <jan.wine at zerebecki.de>
Changelog:
wined3d: Make CreateFakeGLContext thread safe.
---

 dlls/wined3d/directx.c |   23 ++++++++++++++++++++---
 1 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/dlls/wined3d/directx.c b/dlls/wined3d/directx.c
index 3f0aa0a..9e5438b 100644
--- a/dlls/wined3d/directx.c
+++ b/dlls/wined3d/directx.c
@@ -78,11 +78,24 @@ static BOOL            wined3d_fake_gl_context_foreign;
 static BOOL            wined3d_fake_gl_context_available = FALSE;
 static Display*        wined3d_fake_gl_context_display = NULL;
 
+static CRITICAL_SECTION wined3d_fake_gl_context_cs;
+static CRITICAL_SECTION_DEBUG wined3d_fake_gl_context_cs_debug =
+{
+    0, 0, &wined3d_fake_gl_context_cs,
+    { &wined3d_fake_gl_context_cs_debug.ProcessLocksList,
+      &wined3d_fake_gl_context_cs_debug.ProcessLocksList },
+    0, 0, { (DWORD_PTR)(__FILE__ ": wined3d_fake_gl_context_cs") }
+};
+static CRITICAL_SECTION wined3d_fake_gl_context_cs = { &wined3d_fake_gl_context_cs_debug, -1, 0, 0, 0, 0 };
+
 static void WineD3D_ReleaseFakeGLContext(void) {
     GLXContext glCtx;
 
+    EnterCriticalSection(&wined3d_fake_gl_context_cs);
+
     if(!wined3d_fake_gl_context_available) {
         TRACE_(d3d_caps)("context not available\n");
+        LeaveCriticalSection(&wined3d_fake_gl_context_cs);
         return;
     }
 
@@ -95,17 +108,21 @@ static void WineD3D_ReleaseFakeGLContext(void) {
             glXMakeCurrent(wined3d_fake_gl_context_display, None, NULL);
             glXDestroyContext(wined3d_fake_gl_context_display, glCtx);
         }
-        LEAVE_GL();
         wined3d_fake_gl_context_available = FALSE;
     }
     assert(wined3d_fake_gl_context_ref >= 0);
 
+    LeaveCriticalSection(&wined3d_fake_gl_context_cs);
+    LEAVE_GL();
 }
 
 static BOOL WineD3D_CreateFakeGLContext(void) {
     XVisualInfo* visInfo;
     GLXContext   glCtx;
 
+    ENTER_GL();
+    EnterCriticalSection(&wined3d_fake_gl_context_cs);
+
     TRACE_(d3d_caps)("getting context...\n");
     if(wined3d_fake_gl_context_ref > 0) goto ret;
     assert(0 == wined3d_fake_gl_context_ref);
@@ -119,8 +136,6 @@ static BOOL WineD3D_CreateFakeGLContext(void) {
         ReleaseDC(0, device_context);
     }
 
-    ENTER_GL();
-
     visInfo = NULL;
     glCtx = glXGetCurrentContext();
 
@@ -170,10 +185,12 @@ static BOOL WineD3D_CreateFakeGLContext(void) {
     TRACE_(d3d_caps)("incrementing ref from %i\n", wined3d_fake_gl_context_ref);
     wined3d_fake_gl_context_ref++;
     wined3d_fake_gl_context_available = TRUE;
+    LeaveCriticalSection(&wined3d_fake_gl_context_cs);
     return TRUE;
   fail:
     if(visInfo) XFree(visInfo);
     if(glCtx) glXDestroyContext(wined3d_fake_gl_context_display, glCtx);
+    LeaveCriticalSection(&wined3d_fake_gl_context_cs);
     LEAVE_GL();
     return FALSE;
 }