From 93e3f905c8f418ddf0c805fb90a33bf5d7a5b500 Mon Sep 17 00:00:00 2001
From: Francois Boisvert <francois@macadamian.com>
Date: Thu, 25 Feb 1999 17:32:31 +0000
Subject: [PATCH] Adding of new functions to make the wnd struct thread safe.
 Adding of irefCount in wnd struct.

---
 include/win.h |  6 ++++
 windows/win.c | 96 ++++++++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 101 insertions(+), 1 deletion(-)

diff --git a/include/win.h b/include/win.h
index fad66763111..64763f6d927 100644
--- a/include/win.h
+++ b/include/win.h
@@ -79,6 +79,7 @@ typedef struct tagWND
     DWORD          helpContext;   /* Help context ID */
     WORD           flags;         /* Misc. flags (see below) */
     HMENU16        hSysMenu;      /* window's copy of System Menu */
+    int            irefCount;     /* window's reference count*/
     DWORD          userdata;      /* User private data */
     struct _WND_DRIVER *pDriver;  /* Window driver */
     void          *pDriverData;   /* Window driver data */
@@ -133,7 +134,12 @@ typedef struct
 #define BWA_SKIPICONIC		0x0008
 
   /* Window functions */
+extern void   WIN_LockWnds();
+extern void   WIN_UnlockWnds();
+extern int    WIN_SuspendWndsLock();
+extern void   WIN_RestoreWndsLock(int ipreviousLock);
 extern WND*   WIN_FindWndPtr( HWND32 hwnd );
+extern void   WIN_ReleaseWndPtr(WND *wndPtr);
 extern WND*   WIN_GetDesktop(void);
 extern void   WIN_DumpWindow( HWND32 hwnd );
 extern void   WIN_WalkWindows( HWND32 hwnd, int indent );
diff --git a/windows/win.c b/windows/win.c
index f5ef21457ac..408406a0127 100644
--- a/windows/win.c
+++ b/windows/win.c
@@ -52,6 +52,68 @@ static HWND32 hwndSysModal = 0;
 static WORD wDragWidth = 4;
 static WORD wDragHeight= 3;
 
+/* thread safeness */
+static CRITICAL_SECTION WIN_CritSection;
+static int ilockCounter = 0;
+
+/***********************************************************************
+ *           WIN_LockWnds
+ *
+ *   Locks access to all WND structures for thread safeness
+ */
+void WIN_LockWnds()
+{
+    EnterCriticalSection(&WIN_CritSection);
+    ilockCounter++;
+    TRACE(win,"All windows hinstances have been locked (lock #%i)\n",ilockCounter);
+}
+
+/***********************************************************************
+ *           WIN_UnlockWnds
+ *
+ *  Unlocks access to all WND structures
+ */
+void WIN_UnlockWnds()
+{
+
+    TRACE(win,"Lock #%i been unlocked\n",ilockCounter+1);
+    ilockCounter--;
+    if(ilockCounter == 0)
+    {
+        LeaveCriticalSection(&WIN_CritSection);
+        TRACE(win,"All windows hinstances have been unlocked\n");
+    }
+    else if(ilockCounter < 0)
+    {
+        ERR(win,"Negative lock reference ==> missing call to  WIN_Lock!\n");
+    }
+}
+/***********************************************************************
+ *           WIN_SuspendWndsLock
+ *
+ *   Suspend the lock on WND structures.
+ *   Returns the number of locks suspended
+ */
+int WIN_SuspendWndsLock()
+{
+    int isuspendedLocks = ilockCounter;
+    ilockCounter = 0;
+    LeaveCriticalSection(&WIN_CritSection);
+    TRACE(win,"All windows hinstances locks have been suspended\n");
+    return isuspendedLocks;
+
+}
+
+/***********************************************************************
+ *           WIN_RestoreWndsLock
+ *
+ *  Restore the suspended locks on WND structures
+ */
+void WIN_Unlock(int ipreviousLocks)
+{
+    EnterCriticalSection(&WIN_CritSection);
+    ilockCounter = ipreviousLocks;
+}
 /***********************************************************************
  *           WIN_FindWndPtr
  *
@@ -61,8 +123,13 @@ WND * WIN_FindWndPtr( HWND32 hwnd )
 {
     WND * ptr;
     
-    if (!hwnd || HIWORD(hwnd)) goto error;
+    if (!hwnd || HIWORD(hwnd)) goto error2;
     ptr = (WND *) USER_HEAP_LIN_ADDR( hwnd );
+    /* Lock all WND structures for thread safeness
+     WIN_LockWnds();
+     and increment destruction monitoring value
+     ptr->irefCount++;
+     */
     if (ptr->dwMagic != WND_MAGIC) goto error;
     if (ptr->hwndSelf != hwnd)
     {
@@ -72,10 +139,37 @@ WND * WIN_FindWndPtr( HWND32 hwnd )
     }
     return ptr;
  error:
+    /* Unlock all WND structures for thread safeness
+     WIN_UnlockWnds();
+     and decrement destruction monitoring value
+     ptr->irefCount--;
+     */
+error2:
     SetLastError( ERROR_INVALID_WINDOW_HANDLE );
     return NULL;
 }
 
+/***********************************************************************
+ *           WIN_ReleaseWndPtr
+ *
+ * Release the pointer to the WND structure.
+ */
+void WIN_ReleaseWndPtr(WND *wndPtr)
+{
+
+    /*Decrement destruction monitoring value
+     wndPtr->irefCount--;
+     Check if it's time to release the memory
+     if(wndPtr->irefCount == 0)
+     {
+         Add memory releasing code here
+     }
+     unlock all WND structures for thread safeness
+     WIN_UnlockWnds();
+
+     */    
+}
+
 
 /***********************************************************************
  *           WIN_DumpWindow