X-Git-Url: https://pd.if.org/git/?a=blobdiff_plain;f=platform%2Fwin32%2Ffunctions%2Fthreads%2Fmtx_lock.c;h=d16a487b70d26622cb6f6b6eb2dec2340d04e891;hb=875ab9fe96aee3a5fb920163fa0033df8eaae804;hp=70af8ae35bd7cd65c7785527544d7cf7778e2776;hpb=21c5050f9d173dc1ea751cb8d32549d22d01aba8;p=pdclib.old

diff --git a/platform/win32/functions/threads/mtx_lock.c b/platform/win32/functions/threads/mtx_lock.c
index 70af8ae..d16a487 100644
--- a/platform/win32/functions/threads/mtx_lock.c
+++ b/platform/win32/functions/threads/mtx_lock.c
@@ -6,26 +6,20 @@ int mtx_lock(mtx_t *mtx)
 {
     DWORD myId = GetCurrentThreadId();
 
-    if(mtx->_ThreadId == myId) {
+    if(mtx->_ThreadId == (long) myId) {
         mtx->_NestCount++;
         return thrd_success;
     }
 
-    DWORD res = InterlockedIncrement(&mtx->_State);
-    if(res == 0) {
-        mtx->_ThreadId = myId;
-        return thrd_success;
-    }
+    for(;;) {
+        LONG prev = InterlockedCompareExchange(&mtx->_ThreadId, myId, 0);
+        if(prev == 0)
+            return thrd_success;
 
-    // If that increment didn't leave the state == 0, then we have contention
-    //  -> block on the wait event handle
-    DWORD rv = WaitForSingleObject(mtx->_WaitEvHandle, INFINITE);
-    if(rv != WAIT_OBJECT_0) 
-        return thrd_error;
-
-    // We now own the mutex - so set it up for our use
-    mtx->_ThreadId = myId;
-    return thrd_success;
+        DWORD rv = WaitForSingleObject(mtx->_WaitEvHandle, INFINITE);
+        if(rv != WAIT_OBJECT_0)
+            return thrd_error;
+    }
 }
 #endif