notify resource caches when pixelref genID goes stale

src/core/SkPixelRef.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
+#include "SkBitmapCache.h"
 #include "SkPixelRef.h"
 #include "SkThread.h"
 
 #ifdef SK_USE_POSIX_THREADS
 
     static SkBaseMutex gPixelRefMutexRing[] = {
         SK_BASE_MUTEX_INIT, SK_BASE_MUTEX_INIT,
         SK_BASE_MUTEX_INIT, SK_BASE_MUTEX_INIT,
         SK_BASE_MUTEX_INIT, SK_BASE_MUTEX_INIT,
         SK_BASE_MUTEX_INIT, SK_BASE_MUTEX_INIT,
@@ skipping 198 matching lines @@
 
 void SkPixelRef::addGenIDChangeListener(GenIDChangeListener* listener) {
     if (NULL == listener || !fUniqueGenerationID) {
         // No point in tracking this if we're not going to call it.
         SkDELETE(listener);
         return;
     }
     *fGenIDChangeListeners.append() = listener;
 }
 
+// we need to be called *before* the genID gets changed or zerod
 void SkPixelRef::callGenIDChangeListeners() {
     // We don't invalidate ourselves if we think another SkPixelRef is sharing our genID.
     if (fUniqueGenerationID) {
         for (int i = 0; i < fGenIDChangeListeners.count(); i++) {
             fGenIDChangeListeners[i]->onChange();
         }
     }
     // Listeners get at most one shot, so whether these triggered or not, blow them away.
     fGenIDChangeListeners.deleteAll();
+
+    // if fGenerationID is 0, then perhaps we never had one, and we are in the destructor
+    if (fGenerationID) {
+        SkBitmapCache::NotifyGenIDStale(fGenerationID);

[mtklein, 2015/01/07 21:52:43]

Feels weird knowing both these calls really grab and release the same mutex down
under the covers.  No suggested change here though... can't think of anything
that doesn't really slice through the API barriers.

[reed1, 2015/01/07 22:20:41]

Agree on both counts.

*if* we (later) standardize on a genID field, then this problem goes away

[reed1, 2015/02/18 17:30:32]

Captured this comment in a comment.

+        SkMipMapCache::NotifyGenIDStale(fGenerationID);
+    }
 }
 
 void SkPixelRef::notifyPixelsChanged() {
 #ifdef SK_DEBUG
     if (fIsImmutable) {
         SkDebugf("========== notifyPixelsChanged called on immutable pixelref");
     }
 #endif
     this->callGenIDChangeListeners();
     this->needsNewGenID();
@@ skipping 32 matching lines @@
 
 #ifdef SK_BUILD_FOR_ANDROID
 void SkPixelRef::globalRef(void* data) {
     this->ref();
 }
 
 void SkPixelRef::globalUnref() {
     this->unref();
 }
 #endif