From e7d2295c06ef9b9df6336cbff23007a13fb3f6e4 Mon Sep 17 00:00:00 2001
From: Chet Haase <chet@google.com>
Date: Thu, 11 Nov 2010 16:30:16 -0800
Subject: make ResourceCache for display lists thread-safe

Change-Id: I41885b4ae249d7d7c000bab17bf32340ba85ab3a
---
 libs/hwui/ResourceCache.cpp | 13 +++++++++++++
 libs/hwui/ResourceCache.h   |  7 +++++++
 2 files changed, 20 insertions(+)

(limited to 'libs')

diff --git a/libs/hwui/ResourceCache.cpp b/libs/hwui/ResourceCache.cpp
index 9f18948..5ebd2c0 100644
--- a/libs/hwui/ResourceCache.cpp
+++ b/libs/hwui/ResourceCache.cpp
@@ -37,14 +37,17 @@ void ResourceCache::logCache() {
 }
 
 ResourceCache::ResourceCache() {
+    Mutex::Autolock _l(mLock);
     mCache = new KeyedVector<void *, ResourceReference *>();
 }
 
 ResourceCache::~ResourceCache() {
+    Mutex::Autolock _l(mLock);
     delete mCache;
 }
 
 void ResourceCache::incrementRefcount(void* resource, ResourceType resourceType) {
+    Mutex::Autolock _l(mLock);
     for (size_t i = 0; i < mCache->size(); ++i) {
         void* ref = mCache->valueAt(i);
     }
@@ -73,6 +76,7 @@ void ResourceCache::incrementRefcount(SkiaColorFilter* filterResource) {
 }
 
 void ResourceCache::decrementRefcount(void* resource) {
+    Mutex::Autolock _l(mLock);
     ResourceReference* ref = mCache->indexOfKey(resource) >= 0 ? mCache->valueFor(resource) : NULL;
     if (ref == NULL) {
         // Should not get here - shouldn't get a call to decrement if we're not yet tracking it
@@ -101,6 +105,7 @@ void ResourceCache::decrementRefcount(SkiaColorFilter* filterResource) {
 }
 
 void ResourceCache::recycle(SkBitmap* resource) {
+    Mutex::Autolock _l(mLock);
     if (mCache->indexOfKey(resource) < 0) {
         // not tracking this resource; just recycle the pixel data
         resource->setPixels(NULL, NULL);
@@ -110,6 +115,7 @@ void ResourceCache::recycle(SkBitmap* resource) {
 }
 
 void ResourceCache::recycle(void* resource) {
+    Mutex::Autolock _l(mLock);
     ResourceReference* ref = mCache->indexOfKey(resource) >= 0 ? mCache->valueFor(resource) : NULL;
     if (ref == NULL) {
         // Should not get here - shouldn't get a call to recycle if we're not yet tracking it
@@ -122,6 +128,7 @@ void ResourceCache::recycle(void* resource) {
 }
 
 void ResourceCache::destructor(SkBitmap* resource) {
+    Mutex::Autolock _l(mLock);
     ResourceReference* ref = mCache->indexOfKey(resource) >= 0 ? mCache->valueFor(resource) : NULL;
     if (ref == NULL) {
         // If we're not tracking this resource, just delete it
@@ -139,6 +146,7 @@ void ResourceCache::destructor(SkBitmap* resource) {
 }
 
 void ResourceCache::destructor(SkiaShader* resource) {
+    Mutex::Autolock _l(mLock);
     ResourceReference* ref = mCache->indexOfKey(resource) >= 0 ? mCache->valueFor(resource) : NULL;
     if (ref == NULL) {
         // If we're not tracking this resource, just delete it
@@ -156,6 +164,7 @@ void ResourceCache::destructor(SkiaShader* resource) {
 }
 
 void ResourceCache::destructor(SkiaColorFilter* resource) {
+    Mutex::Autolock _l(mLock);
     ResourceReference* ref = mCache->indexOfKey(resource) >= 0 ? mCache->valueFor(resource) : NULL;
     if (ref == NULL) {
         // If we're not tracking this resource, just delete it
@@ -169,6 +178,10 @@ void ResourceCache::destructor(SkiaColorFilter* resource) {
     }
 }
 
+/**
+ * This method should only be called while the mLock mutex is held (that mutex is grabbed
+ * by the various destructor() and recycle() methods which call this method).
+ */
 void ResourceCache::deleteResourceReference(void* resource, ResourceReference* ref) {
     if (ref->recycled && ref->resourceType == kBitmap) {
         ((SkBitmap*) resource)->setPixels(NULL, NULL);
diff --git a/libs/hwui/ResourceCache.h b/libs/hwui/ResourceCache.h
index 2256fd1..b0abe2c 100644
--- a/libs/hwui/ResourceCache.h
+++ b/libs/hwui/ResourceCache.h
@@ -70,6 +70,13 @@ private:
     void deleteResourceReference(void* resource, ResourceReference* ref);
     void incrementRefcount(void* resource, ResourceType resourceType);
     void logCache();
+
+    /**
+     * Used to increment, decrement, and destroy. Incrementing is generally accessed on the UI
+     * thread, but destroying resources may be called from the GC thread, the finalizer thread,
+     * or a reference queue finalization thread.
+     */
+    mutable Mutex mLock;
 };
 
 }; // namespace uirenderer
-- 
cgit v1.1