ntdll: Implement NtReleaseMutant().

dlls/ntdll/unix/esync.c

@@ -424,6 +424,40 @@ NTSTATUS esync_create_mutex( HANDLE *handle, ACCESS_MASK access,
     return create_esync( ESYNC_MUTEX, handle, access, attr, initial ? 0 : 1, 0 );
 }
 
+NTSTATUS esync_release_mutex( HANDLE *handle, LONG *prev )
+{
+    struct esync *obj;
+    struct mutex *mutex;
+    static const uint64_t value = 1;
+    NTSTATUS ret;
+
+    TRACE("%p, %p.\n", handle, prev);
+
+    if ((ret = get_object( handle, &obj ))) return ret;
+    mutex = obj->shm;
+
+    /* This is thread-safe, because the only thread that can change the tid to
+     * or from our tid is ours. */
+    if (mutex->tid != GetCurrentThreadId()) return STATUS_MUTANT_NOT_OWNED;
+
+    if (prev) *prev = mutex->count;
+
+    mutex->count--;
+
+    if (!mutex->count)
+    {
+        /* This is also thread-safe, as long as signaling the file is the last
+         * thing we do. Other threads don't care about the tid if it isn't
+         * theirs. */
+        mutex->tid = 0;
+
+        if (write( obj->fd, &value, sizeof(value) ) == -1)
+            return errno_to_status( errno );
+    }
+
+    return STATUS_SUCCESS;
+}
+
 #define TICKSPERSEC        10000000
 #define TICKSPERMSEC       10000
 

dlls/ntdll/unix/esync.h

@@ -33,6 +33,7 @@ extern NTSTATUS esync_set_event( HANDLE handle ) DECLSPEC_HIDDEN;
 
 extern NTSTATUS esync_create_mutex( HANDLE *handle, ACCESS_MASK access,
     const OBJECT_ATTRIBUTES *attr, BOOLEAN initial ) DECLSPEC_HIDDEN;
+extern NTSTATUS esync_release_mutex( HANDLE *handle, LONG *prev ) DECLSPEC_HIDDEN;
 
 extern NTSTATUS esync_wait_objects( DWORD count, const HANDLE *handles, BOOLEAN wait_any,
                                     BOOLEAN alertable, const LARGE_INTEGER *timeout ) DECLSPEC_HIDDEN;

dlls/ntdll/unix/sync.c

@@ -609,6 +609,9 @@ NTSTATUS WINAPI NtReleaseMutant( HANDLE handle, LONG *prev_count )
 {
     NTSTATUS ret;
 
+    if (do_esync())
+        return esync_release_mutex( handle, prev_count );
+
     SERVER_START_REQ( release_mutex )
     {
         req->handle = wine_server_obj_handle( handle );