Re-initialize the 9patch cache if cleared with onTrimMemory

The 9aptch cache was reinitialized after destroying/recreating
the EGL context but not after clearing it during a normal
memory trim.

Change-Id: If6155bfc8a62439e9878bc742a4766b3bd6c6aec

2 files changed, 21 insertions, 8 deletions

diff --git a/libs/hwui/PatchCache.cpp b/libs/hwui/PatchCache.cpp
index c2b28d1..c6ed275 100644
--- a/libs/hwui/PatchCache.cpp
+++ b/libs/hwui/PatchCache.cpp
@@ -40,6 +40,7 @@ PatchCache::PatchCache(): mCache(LruCache<PatchDescription, Patch*>::kUnlimitedC
         mMaxSize = KB(DEFAULT_PATCH_CACHE_SIZE);
     }
     mSize = 0;
+    mMeshBuffer = 0;
 }
 
 PatchCache::~PatchCache() {
@@ -47,11 +48,18 @@ PatchCache::~PatchCache() {
 }
 
 void PatchCache::init(Caches& caches) {
-    glGenBuffers(1, &mMeshBuffer);
+    bool created = false;
+    if (!mMeshBuffer) {
+        glGenBuffers(1, &mMeshBuffer);
+        created = true;
+    }
+
     caches.bindMeshBuffer(mMeshBuffer);
     caches.resetVertexPointers();
 
-    glBufferData(GL_ARRAY_BUFFER, mMaxSize, NULL, GL_DYNAMIC_DRAW);
+    if (created) {
+        glBufferData(GL_ARRAY_BUFFER, mMaxSize, NULL, GL_DYNAMIC_DRAW);
+    }
 }
 
 ///////////////////////////////////////////////////////////////////////////////
@@ -73,9 +81,14 @@ int PatchCache::PatchDescription::compare(const PatchCache::PatchDescription& lh
 }
 
 void PatchCache::clear() {
-    glDeleteBuffers(1, &mMeshBuffer);
     clearCache();
-    mSize = 0;
+
+    if (mMeshBuffer) {
+        Caches::getInstance().unbindMeshBuffer();
+        glDeleteBuffers(1, &mMeshBuffer);
+        mMeshBuffer = 0;
+        mSize = 0;
+    }
 }
 
 void PatchCache::clearCache() {
@@ -106,9 +119,8 @@ const Patch* PatchCache::get(const AssetAtlas::Entry* entry,
         }
 
         if (vertices) {
-            Caches& caches = Caches::getInstance();
-            caches.bindMeshBuffer(mMeshBuffer);
-            caches.resetVertexPointers();
+            // This call ensures the VBO exists and that it is bound
+            init(Caches::getInstance());
 
             // TODO: Simply remove the oldest items until we have enough room
             // This will require to keep a list of free blocks in the VBO
diff --git a/libs/hwui/PatchCache.h b/libs/hwui/PatchCache.h
index 129a0dc..530dad0 100644
--- a/libs/hwui/PatchCache.h
+++ b/libs/hwui/PatchCache.h
@@ -121,9 +121,10 @@ private:
 
     uint32_t mMaxSize;
     uint32_t mSize;
-    LruCache<PatchDescription, Patch*> mCache;
 
     GLuint mMeshBuffer;
+
+    LruCache<PatchDescription, Patch*> mCache;
 }; // class PatchCache
 
 }; // namespace uirenderer