Notify resource caches when pixelref genID goes stale

src/core/SkResourceCache.h

Index: src/core/SkResourceCache.h
diff --git a/src/core/SkResourceCache.h b/src/core/SkResourceCache.h
index 88ccb87ed88443ece5f5b6113fe737f142935713..a3c52df422781c113b33a6c39451df85b9783094 100644
--- a/src/core/SkResourceCache.h
+++ b/src/core/SkResourceCache.h
@@ -9,6 +9,7 @@
 #define SkResourceCache_DEFINED
 
 #include "SkBitmap.h"
+#include "SkTDArray.h"
 
 class SkCachedData;
 class SkDiscardableMemory;
@@ -33,7 +34,10 @@ public:
         // must call this after your private data has been written.
         // nameSpace must be unique per Key subclass.
         // length must be a multiple of 4
-        void init(void* nameSpace, size_t length);
+        void init(void* nameSpace, uint64_t sharedID, size_t length);

[mtklein, 2015/02/24 16:43:39]

Why don't we call this uniqueID?  I hate to add another fooID name to think
about.

Let's put the note about 0 being special up here too?

[reed2, 2015/02/24 17:44:52]

I don't think its unique, since it may appear in several entries. I thought
"shared" was an important term here.

+
+        void* getNamespace() const { return fNamespace; }
+        uint64_t getSharedID() const { return fSharedID; }
 
         // This is only valid after having called init().
         uint32_t hash() const { return fHash; }
@@ -52,6 +56,7 @@ public:
     private:
         int32_t  fCount32;   // local + user contents count32
         uint32_t fHash;
+        uint64_t fSharedID;  // 0 means ignore (nothing is shared)
         void*    fNamespace; // A unique namespace tag. This is hashed.
         /* uint32_t fContents32[] */
 
@@ -92,7 +97,7 @@ public:
      *  true, then the Rec is considered "valid". If false is returned, the Rec will be considered
      *  "stale" and will be purged from the cache.
      */
-    typedef bool (*VisitorProc)(const Rec&, void* context);
+    typedef bool (*FindVisitor)(const Rec&, void* context);
 
     /**
      *  Returns a locked/pinned SkDiscardableMemory instance for the specified
@@ -114,7 +119,7 @@ public:
      *      true  : Rec is valid
      *      false : Rec is "stale" -- the cache will purge it.
      */
-    static bool Find(const Key& key, VisitorProc, void* context);
+    static bool Find(const Key& key, FindVisitor, void* context);
     static void Add(Rec*);
 
     static size_t GetTotalBytesUsed();
@@ -125,6 +130,11 @@ public:
     static size_t GetSingleAllocationByteLimit();
     static size_t GetEffectiveSingleAllocationByteLimit();
 
+    /**
+     *  Purge all Recs that match the specified sharedID. Passing 0 does nothing.
+     */
+    static void PurgeSharedID(uint64_t sharedID);

[mtklein, 2015/02/24 16:43:39]

Seems like we don't need both PurgeSharedID and PostPurgeSharedID?

[reed2, 2015/02/24 17:44:52]

Ah, good point. Don't need the purger, just the poster.

+
     static void PurgeAll();
 
     /**
@@ -140,6 +150,8 @@ public:
 
     static SkCachedData* NewCachedData(size_t bytes);
 
+    static void PostPurgeSharedID(uint64_t sharedID);
+
     /**
      *  Call SkDebugf() with diagnostic information about the state of the cache
      */
@@ -174,7 +186,7 @@ public:
      *      true  : Rec is valid
      *      false : Rec is "stale" -- the cache will purge it.
      */
-    bool find(const Key&, VisitorProc, void* context);
+    bool find(const Key&, FindVisitor, void* context);
     void add(Rec*);
 
     size_t getTotalBytesUsed() const { return fTotalBytesUsed; }
@@ -198,6 +210,8 @@ public:
      */
     size_t setTotalByteLimit(size_t newLimit);
 
+    void purgeSharedID(uint64_t sharedID);

[mtklein, 2015/02/24 16:43:39]

Probably can be private?

[reed2, 2015/02/24 17:44:52]

public like the others for testing. (which I need to add :)

+
     void purgeAll() {
         this->purgeAsNeeded(true);
     }
@@ -228,6 +242,7 @@ private:
     size_t  fSingleAllocationByteLimit;
     int     fCount;
 
+    void checkMessages();
     void purgeAsNeeded(bool forcePurge = false);
 
     // linklist management
@@ -238,6 +253,8 @@ private:
 
     void init();    // called by constructors
 
+    static SkTDArray<uint64_t>* DetachPurgeMessages();
+
 #ifdef SK_DEBUG
     void validate() const;
 #else