Use the GrCacheable ID to eliminate the need for notifications to GrGpuGL when textures and RTs are…

src/gpu/GrCacheable.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "GrCacheable.h"
 
-uint32_t GrCacheable::getGenerationID() const {
-    static int32_t gPathRefGenerationID;
-    while (!fGenID) {
-        fGenID = static_cast<uint32_t>(sk_atomic_inc(&gPathRefGenerationID) + 1);
-    }
-    return fGenID;
+uint32_t GrCacheable::CreateInstanceID() {
+    static int32_t gCacheableID;

[jvanverth1, 2014/07/08 19:35:43]

Since 0 means 'no entry' in fHWBoundRenderTargetInstanceID, etc., shouldn't this
be initialized to 0 just to make sure we (practically) never hit it?

[bsalomon, 2014/07/08 19:39:12]

It is! All static POD types are initialized to 0.

Also, the loop below handles the unlikely case of wrapping back to 0 (though we
might have problems with duplicate IDs at that point).

+    uint32_t id;
+    do {
+        id = static_cast<uint32_t>(sk_atomic_inc(&gCacheableID) + 1);
+    } while (!id);
+    return id;
 }