add more tests for discardable caches

BUG=
R=halcanary@google.com

Review URL: https://codereview.chromium.org/112833003

git-svn-id: http://skia.googlecode.com/svn/trunk@12618 2bbb7eff-a529-9590-31e7-b0007b416f81

src/core/SkScaledImageCache.cpp

@@ -209,6 +209,7 @@ private:
     SkDiscardableMemory* fDM;
     size_t               fRB;
     bool                 fFirstTime;
+    bool                 fIsLocked;
 
     typedef SkPixelRef INHERITED;
 };
@@ -224,6 +225,7 @@ SkOneShotDiscardablePixelRef::SkOneShotDiscardablePixelRef(const SkImageInfo& in
 
     SkASSERT(dm->data());
     fFirstTime = true;
+    fIsLocked = false;
 }
 
 SkOneShotDiscardablePixelRef::~SkOneShotDiscardablePixelRef() {
@@ -236,12 +238,18 @@ void* SkOneShotDiscardablePixelRef::onLockPixels(SkColorTable** ctable) {
         fFirstTime = false;
         return fDM->data();
     }
-    return fDM->lock() ? fDM->data() : NULL;
+
+    SkASSERT(!fIsLocked);
+    fIsLocked = fDM->lock();
+    return fIsLocked ? fDM->data() : NULL;
 }
 
 void SkOneShotDiscardablePixelRef::onUnlockPixels() {
     SkASSERT(!fFirstTime);
-    fDM->unlock();
+    if (fIsLocked) {
+        fIsLocked = false;
+        fDM->unlock();
+    }
 }
 
 size_t SkOneShotDiscardablePixelRef::getAllocatedSizeInBytes() const {

src/lazy/SkDiscardableMemoryPool.h

@@ -12,6 +12,8 @@
 #include "SkTInternalLList.h"
 #include "SkThread.h"
 
+class SkPoolDiscardableMemory;
+
 #ifdef SK_DEBUG
     #define LAZY_CACHE_STATS 1
 #elif !defined(LAZY_CACHE_STATS)
@@ -22,20 +24,22 @@
  *  This non-global pool can be used for unit tests to verify that the
  *  pool works.
  */
-class SkPoolDiscardableMemory;
 class SkDiscardableMemoryPool : public SkDiscardableMemory::Factory {
 public:
     /**
      *  Without mutex, will be not be thread safe.
      */
     SkDiscardableMemoryPool(size_t budget, SkBaseMutex* mutex = NULL);
-    ~SkDiscardableMemoryPool();
-    SkDiscardableMemory* create(size_t bytes) SK_OVERRIDE;
+    virtual ~SkDiscardableMemoryPool();
+
+    virtual SkDiscardableMemory* create(size_t bytes) SK_OVERRIDE;
+
     size_t getRAMUsed();
     void setRAMBudget(size_t budget);
+
     /** purges all unlocked DMs */
     void dumpPool();
-    friend class SkPoolDiscardableMemory;
+
     #if LAZY_CACHE_STATS
     int          fCacheHits;
     int          fCacheMisses;
@@ -46,6 +50,7 @@ private:
     size_t       fBudget;
     size_t       fUsed;
     SkTInternalLList<SkPoolDiscardableMemory> fList;
+
     /** Function called to free memory if needed */
     void dumpDownTo(size_t budget);
     /** called by SkDiscardableMemoryPool upon destruction */
@@ -54,6 +59,9 @@ private:
     bool lock(SkPoolDiscardableMemory* dm);
     /** called by SkDiscardableMemoryPool::unlock() */
     void unlock(SkPoolDiscardableMemory* dm);
+
+    friend class SkPoolDiscardableMemory;
+
     typedef SkDiscardableMemory::Factory INHERITED;
 };
 

tests/ImageCacheTest.cpp

@@ -1,4 +1,4 @@
-/*
+ /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
@@ -23,12 +23,15 @@ static void test_cache(skiatest::Reporter* reporter, SkScaledImageCache& cache,
 
     SkBitmap bm[COUNT];
 
-    SkScalar scale = 2;
+    const SkScalar scale = 2;
+    for (int i = 0; i < COUNT; ++i) {
+        make_bm(&bm[i], DIM, DIM);
+    }
+    
     for (int i = 0; i < COUNT; ++i) {
         SkBitmap tmp;
 
-        make_bm(&bm[i], DIM, DIM);
-        id = cache.findAndLock(bm[i], scale, scale, &tmp);
+        SkScaledImageCache::ID* id = cache.findAndLock(bm[i], scale, scale, &tmp);
         REPORTER_ASSERT(reporter, NULL == id);
 
         make_bm(&tmp, DIM, DIM);
@@ -49,26 +52,52 @@ static void test_cache(skiatest::Reporter* reporter, SkScaledImageCache& cache,
 
     if (testPurge) {
         // stress test, should trigger purges
+        float incScale = 2;
         for (size_t i = 0; i < COUNT * 100; ++i) {
-            scale += 1;
+            incScale += 1;
 
             SkBitmap tmp;
-
             make_bm(&tmp, DIM, DIM);
-            id = cache.addAndLock(bm[0], scale, scale, tmp);
+
+            SkScaledImageCache::ID* id = cache.addAndLock(bm[0], incScale,
+                                                          incScale, tmp);
             REPORTER_ASSERT(reporter, NULL != id);
             cache.unlock(id);
         }
     }
+
+    // test the originals after all that purging
+    for (int i = 0; i < COUNT; ++i) {
+        SkBitmap tmp;
+        id = cache.findAndLock(bm[i], scale, scale, &tmp);
+        if (id) {
+            cache.unlock(id);
+        }
+    }
+
     cache.setByteLimit(0);
 }
 
+#include "SkDiscardableMemoryPool.h"
+
+static SkDiscardableMemoryPool* gPool;
+static SkDiscardableMemory* pool_factory(size_t bytes) {
+    return gPool->create(bytes);
+}
+
 static void TestImageCache(skiatest::Reporter* reporter) {
+    static const size_t defLimit = DIM * DIM * 4 * COUNT + 1024;    // 1K slop
+
     {
-        static const size_t defLimit = DIM * DIM * 4 * COUNT + 1024;    // 1K slop
         SkScaledImageCache cache(defLimit);
         test_cache(reporter, cache, true);
     }
+    {
+        SkDiscardableMemoryPool pool(defLimit);
+        gPool = &pool;
+        SkScaledImageCache cache(pool_factory);
+        test_cache(reporter, cache, true);
+    }
     {
         SkScaledImageCache cache(SkDiscardableMemory::Create);
         test_cache(reporter, cache, false);