Reimplement gpu message bus for invalidated bitmap gen IDs

include/core/SkTArray.h

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkTArray_DEFINED
 #define SkTArray_DEFINED
 
@@ skipping 252 matching lines @@
     void resize_back(int newCount) {
         SkASSERT(newCount >= 0);
 
         if (newCount > fCount) {
             this->push_back_n(newCount - fCount);
         } else if (newCount < fCount) {
             this->pop_back_n(fCount - newCount);
         }
     }
 
+    /** Swaps the contents of this array with that array. Does a pointer swap if possible,
+        otherwise copies the T values. */
+    void swap(SkTArray* that) {
+        if (this->fPreAllocMemArray != this->fItemArray &&
+            that->fPreAllocMemArray != that->fItemArray) {
+            // If neither is using a preallocated array then just swap.
+            SkTSwap(fItemArray, that->fItemArray);
+            SkTSwap(fCount, that->fCount);
+            SkTSwap(fAllocCount, that->fAllocCount);
+        } else {
+            // This could be more optimal...
+            SkTArray copy(*that);
+            *that = *this;
+            *this = copy;
+        }
+    }
+
     T* begin() {
         return fItemArray;
     }
     const T* begin() const {
         return fItemArray;
     }
     T* end() {
         return fItemArray ? fItemArray + fCount : NULL;
     }
     const T* end() const {
@@ skipping 85 matching lines @@
      * Copy a C array, using preallocated storage if preAllocCount >=
      * count. Otherwise storage will only be used when array shrinks
      * to fit.
      */
     template <int N>
     SkTArray(const T* array, int count, SkAlignedSTStorage<N,T>* storage) {
         this->init(array, count, storage->get(), N);
     }
 
     void init(const T* array, int count,
-               void* preAllocStorage, int preAllocOrReserveCount) {
+              void* preAllocStorage, int preAllocOrReserveCount) {
         SkASSERT(count >= 0);
         SkASSERT(preAllocOrReserveCount >= 0);
         fCount              = count;
         fReserveCount       = (preAllocOrReserveCount > 0) ?
                                     preAllocOrReserveCount :
                                     gMIN_ALLOC_COUNT;
         fPreAllocMemArray   = preAllocStorage;
         if (fReserveCount >= fCount &&
             preAllocStorage) {
             fAllocCount = fReserveCount;
@@ skipping 56 matching lines @@
     friend void* operator new<T>(size_t, SkTArray*, int);
 
     template<typename X> friend void SkTArrayExt::copy(SkTArray<X, true>* that, int dst, int src);
     template<typename X> friend void SkTArrayExt::copy(SkTArray<X, true>* that, const X*);
     template<typename X> friend void SkTArrayExt::copyAndDelete(SkTArray<X, true>* that, char*);
 
     template<typename X> friend void SkTArrayExt::copy(SkTArray<X, false>* that, int dst, int src);
     template<typename X> friend void SkTArrayExt::copy(SkTArray<X, false>* that, const X*);
     template<typename X> friend void SkTArrayExt::copyAndDelete(SkTArray<X, false>* that, char*);
 
-    int fReserveCount;
-    int fCount;
-    int fAllocCount;
-    void*    fPreAllocMemArray;
+    int     fReserveCount;
+    int     fCount;
+    int     fAllocCount;
+    void*   fPreAllocMemArray;
     union {
         T*       fItemArray;
         void*    fMemArray;
     };
 };
 
 // Use the below macro (SkNEW_APPEND_TO_TARRAY) rather than calling this directly
 template <typename T, bool MEM_COPY>
 void* operator new(size_t, SkTArray<T, MEM_COPY>* array, int SkDEBUGCODE(atIndex)) {
     // Currently, we only support adding to the end of the array. When the array class itself
@@ skipping 51 matching lines @@
     SkSTArray& operator= (const INHERITED& array) {
         INHERITED::operator=(array);
         return *this;
     }
 
 private:
     SkAlignedSTStorage<N,T> fStorage;
 };
 
 #endif