Make GrResourceCache dynamically change between LRU and random replacement strategies.

src/gpu/GrDrawingManager.cpp

Index: src/gpu/GrDrawingManager.cpp
diff --git a/src/gpu/GrDrawingManager.cpp b/src/gpu/GrDrawingManager.cpp
index e8cea756228c210e204ac95bca011071c94a6dfc..4cee34ec7f45e10dc73cd9c0a0dd347eb1b3c086 100644
--- a/src/gpu/GrDrawingManager.cpp
+++ b/src/gpu/GrDrawingManager.cpp
@@ -129,10 +129,12 @@ void GrDrawingManager::internalFlush(GrResourceCache::FlushType type) {
 #endif
 
     fFlushState.reset();
-    // We always have to notify the cache when it requested a flush so it can reset its state.
-    if (flushed || type == GrResourceCache::FlushType::kCacheRequested) {
+    // Avoid notifying the cache about redundant client flushes.

[robertphillips, 2016/09/13 13:05:21]

Should this 'fLastFlushType' be 'type' ?
I guess I'm not groking what's going on here

[bsalomon, 2016/09/13 13:31:32]

Changing it slightly to:

    // Avoid notifying the cache about successive client flushes where no
rendering occurred between
    // them.
    bool skipNotify = false;
    if (!flushed) {
        skipNotify = GrResourceCache::kExternal == fLastFlushType &&
                     GrResourceCache::kExternal == type;
    }


which hopefully is more correct and clear.

[robertphillips, 2016/09/13 13:56:48]

That is far clearer. \o/

+    bool skipNotify = !flushed && GrResourceCache::kExternal != fLastFlushType;
+    if (!skipNotify) {
         fContext->getResourceCache()->notifyFlushOccurred(type);
     }
+    fLastFlushType = type;
     fFlushing = false;
 }
 
@@ -145,6 +147,9 @@ void GrDrawingManager::prepareSurfaceForExternalIO(GrSurface* surface) {
 
     if (surface->surfacePriv().hasPendingIO()) {
         this->flush();
+    } else if (GrResourceCache::kExternal != fLastFlushType) {
+        fContext->getResourceCache()->notifyFlushOccurred(GrResourceCache::kExternal);
+        fLastFlushType = GrResourceCache::kExternal;
     }
 
     GrRenderTarget* rt = surface->asRenderTarget();