commit 9631337be0f463ede106c5dbca69d726795f6ccf
author commit-bot@chromium.org <commit-bot@chromium.org@2bbb7eff-a529-9590-31e7-b0007b416f81> Wed Apr 16 16:17:39 2014 +0000
committer commit-bot@chromium.org <commit-bot@chromium.org@2bbb7eff-a529-9590-31e7-b0007b416f81> Wed Apr 16 16:17:39 2014 +0000
tree 7751384b75bbf36d7c3d3236b974c7633d494388
parent 6c508885b68e459724984eff6822dac3523fa001

Fix memory leak in SkGradientShader.

Make sure pointer to gradient shader cache is unreffed in SkGradientShaderBase::getGradientTableBitmap.
Rename methods returning a "pre-reffed" object to indicate obligations.

BUG=skia:1976
R=reed@google.com, scroggo@google.com

Author: dominikg@chromium.org

Review URL: https://codereview.chromium.org/240303003

git-svn-id: http://skia.googlecode.com/svn/trunk@14223 2bbb7eff-a529-9590-31e7-b0007b416f81

src/core/SkPictureShader.cpp

diff --git a/src/core/SkPictureShader.cpp b/src/core/SkPictureShader.cpp
index 1e95071..7110a5b 100644
--- a/src/core/SkPictureShader.cpp
+++ b/src/core/SkPictureShader.cpp
@@ -55,7 +55,7 @@
     }
 }
 
-SkShader* SkPictureShader::buildBitmapShader(const SkMatrix& matrix) const {
+SkShader* SkPictureShader::refBitmapShader(const SkMatrix& matrix) const {
     if (!fPicture || (0 == fPicture->width() && 0 == fPicture->height())) {
         return NULL;
     }
@@ -121,17 +121,12 @@
         return NULL;
     }
 
-    SkShader* bitmapShader = this->buildBitmapShader(matrix);
-    if (!bitmapShader) {
+    SkAutoTUnref<SkShader> bitmapShader(this->refBitmapShader(matrix));
+    if (!bitmapShader || !bitmapShader->validContext(device, paint, matrix)) {
         return NULL;
     }
 
-    if (!bitmapShader->validContext(device, paint, matrix)) {
-        bitmapShader->unref();
-        return NULL;
-    }
-
-    return bitmapShader;
+    return bitmapShader.detach();
 }
 
 bool SkPictureShader::validContext(const SkBitmap& device, const SkPaint& paint,
@@ -142,13 +137,13 @@
 
 SkShader::Context* SkPictureShader::createContext(const SkBitmap& device, const SkPaint& paint,
                                                   const SkMatrix& matrix, void* storage) const {
-    SkShader* bitmapShader = this->validInternal(device, paint, matrix, NULL);
+    SkAutoTUnref<SkShader> bitmapShader(this->validInternal(device, paint, matrix, NULL));
     if (!bitmapShader) {
         return NULL;
     }
 
     return SkNEW_PLACEMENT_ARGS(storage, PictureShaderContext,
-                                (*this, device, paint, matrix, bitmapShader));
+                                (*this, device, paint, matrix, bitmapShader.detach()));
 }
 
 size_t SkPictureShader::contextSize() const {
@@ -209,7 +204,7 @@
 
 #if SK_SUPPORT_GPU
 GrEffectRef* SkPictureShader::asNewEffect(GrContext* context, const SkPaint& paint) const {
-    SkAutoTUnref<SkShader> bitmapShader(this->buildBitmapShader(context->getMatrix()));
+    SkAutoTUnref<SkShader> bitmapShader(this->refBitmapShader(context->getMatrix()));
     if (!bitmapShader) {
         return NULL;
     }

src/core/SkPictureShader.h

diff --git a/src/core/SkPictureShader.h b/src/core/SkPictureShader.h
index a0a377d..d1be059 100644
--- a/src/core/SkPictureShader.h
+++ b/src/core/SkPictureShader.h
@@ -69,7 +69,7 @@
     SkShader* validInternal(const SkBitmap& device, const SkPaint& paint,
                             const SkMatrix& matrix, SkMatrix* totalInverse) const;
 
-    SkShader* buildBitmapShader(const SkMatrix&) const;
+    SkShader* refBitmapShader(const SkMatrix&) const;
 
     SkPicture*  fPicture;
     TileMode    fTmx, fTmy;

src/effects/gradients/SkGradientShader.cpp

diff --git a/src/effects/gradients/SkGradientShader.cpp b/src/effects/gradients/SkGradientShader.cpp
index 666204e..3547fbe 100644
--- a/src/effects/gradients/SkGradientShader.cpp
+++ b/src/effects/gradients/SkGradientShader.cpp
@@ -211,7 +211,7 @@
         const SkGradientShaderBase& shader, const SkBitmap& device,
         const SkPaint& paint, const SkMatrix& matrix)
     : INHERITED(shader, device, paint, matrix)
-    , fCache(shader.getCache(getPaintAlpha()))
+    , fCache(shader.refCache(getPaintAlpha()))
 {
     const SkMatrix& inverse = this->getTotalInverse();
 
@@ -558,7 +558,7 @@
  *  The gradient holds a cache for the most recent value of alpha. Successive
  *  callers with the same alpha value will share the same cache.
  */
-SkGradientShaderBase::GradientShaderCache* SkGradientShaderBase::getCache(U8CPU alpha) const {
+SkGradientShaderBase::GradientShaderCache* SkGradientShaderBase::refCache(U8CPU alpha) const {
     SkAutoMutexAcquire ama(fCacheMutex);
     if (!fCache || fCache->getAlpha() != alpha) {
         fCache.reset(SkNEW_ARGS(GradientShaderCache, (alpha, *this)));
@@ -581,7 +581,7 @@
 void SkGradientShaderBase::getGradientTableBitmap(SkBitmap* bitmap) const {
     // our caller assumes no external alpha, so we ensure that our cache is
     // built with 0xFF
-    GradientShaderCache* cache = this->getCache(0xFF);
+    SkAutoTUnref<GradientShaderCache> cache(this->refCache(0xFF));
 
     // don't have a way to put the mapper into our cache-key yet
     if (fMapper) {

src/effects/gradients/SkGradientShaderPriv.h

diff --git a/src/effects/gradients/SkGradientShaderPriv.h b/src/effects/gradients/SkGradientShaderPriv.h
index e016094..1d0f008 100644
--- a/src/effects/gradients/SkGradientShaderPriv.h
+++ b/src/effects/gradients/SkGradientShaderPriv.h
@@ -215,7 +215,7 @@
     SkColor*    fOrigColors; // original colors, before modulation by paint in context.
     bool        fColorsAreOpaque;
 
-    GradientShaderCache* getCache(U8CPU alpha) const;
+    GradientShaderCache* refCache(U8CPU alpha) const;
     mutable SkMutex                           fCacheMutex;
     mutable SkAutoTUnref<GradientShaderCache> fCache;