Fix crash where trim memory resulted in HWUI deleting the surface.

When HWUI is given the TRIM_MEMORY_COMPLETE signal it deletes all
of the associated GPU resources. In doing so it also deleted the
GL/Vk handle to the the ANativeWindow. So if the app attempted to
recover and draw new content it would crash because we no longer
had a surface to reinitialize and render into.

Test: atest hwui_unit_tests
Bug: 233388563
Change-Id: I54f3f0dadc3dfc89d2b1f567d36611f6a966c4f0
(cherry picked from commit b830772f78)

libs/hwui/pipeline/skia/SkiaOpenGLPipeline.cpp

@@ -53,8 +53,12 @@ SkiaOpenGLPipeline::~SkiaOpenGLPipeline() {
 }
 
 MakeCurrentResult SkiaOpenGLPipeline::makeCurrent() {
-    // TODO: Figure out why this workaround is needed, see b/13913604
-    // In the meantime this matches the behavior of GLRenderer, so it is not a regression
+    // In case the surface was destroyed (e.g. a previous trimMemory call) we
+    // need to recreate it here.
+    if (!isSurfaceReady() && mNativeWindow) {
+        setSurface(mNativeWindow.get(), mSwapBehavior);
+    }
+
     EGLint error = 0;
     if (!mEglManager.makeCurrent(mEglSurface, &error)) {
         return MakeCurrentResult::AlreadyCurrent;
@@ -166,6 +170,9 @@ void SkiaOpenGLPipeline::onStop() {
 }
 
 bool SkiaOpenGLPipeline::setSurface(ANativeWindow* surface, SwapBehavior swapBehavior) {
+    mNativeWindow = surface;
+    mSwapBehavior = swapBehavior;
+
     if (mEglSurface != EGL_NO_SURFACE) {
         mEglManager.destroySurface(mEglSurface);
         mEglSurface = EGL_NO_SURFACE;
@@ -182,7 +189,8 @@ bool SkiaOpenGLPipeline::setSurface(ANativeWindow* surface, SwapBehavior swapBeh
 
     if (mEglSurface != EGL_NO_SURFACE) {
         const bool preserveBuffer = (swapBehavior != SwapBehavior::kSwap_discardBuffer);
-        mBufferPreserved = mEglManager.setPreserveBuffer(mEglSurface, preserveBuffer);
+        const bool isPreserved = mEglManager.setPreserveBuffer(mEglSurface, preserveBuffer);
+        ALOGE_IF(preserveBuffer != isPreserved, "Unable to match the desired swap behavior.");
         return true;
     }
 

libs/hwui/pipeline/skia/SkiaOpenGLPipeline.h

@@ -61,7 +61,8 @@ protected:
 private:
     renderthread::EglManager& mEglManager;
     EGLSurface mEglSurface = EGL_NO_SURFACE;
-    bool mBufferPreserved = false;
+    sp<ANativeWindow> mNativeWindow;
+    renderthread::SwapBehavior mSwapBehavior = renderthread::SwapBehavior::kSwap_discardBuffer;
 };
 
 } /* namespace skiapipeline */

libs/hwui/pipeline/skia/SkiaVulkanPipeline.cpp

@@ -55,7 +55,12 @@ VulkanManager& SkiaVulkanPipeline::vulkanManager() {
 }
 
 MakeCurrentResult SkiaVulkanPipeline::makeCurrent() {
-    return MakeCurrentResult::AlreadyCurrent;
+    // In case the surface was destroyed (e.g. a previous trimMemory call) we
+    // need to recreate it here.
+    if (!isSurfaceReady() && mNativeWindow) {
+        setSurface(mNativeWindow.get(), SwapBehavior::kSwap_default);
+    }
+    return isContextReady() ? MakeCurrentResult::AlreadyCurrent : MakeCurrentResult::Failed;
 }
 
 Frame SkiaVulkanPipeline::getFrame() {
@@ -130,7 +135,11 @@ DeferredLayerUpdater* SkiaVulkanPipeline::createTextureLayer() {
 
 void SkiaVulkanPipeline::onStop() {}
 
-bool SkiaVulkanPipeline::setSurface(ANativeWindow* surface, SwapBehavior swapBehavior) {
+// We can safely ignore the swap behavior because VkManager will always operate
+// in a mode equivalent to EGLManager::SwapBehavior::kBufferAge
+bool SkiaVulkanPipeline::setSurface(ANativeWindow* surface, SwapBehavior /*swapBehavior*/) {
+    mNativeWindow = surface;
+
     if (mVkSurface) {
         vulkanManager().destroySurface(mVkSurface);
         mVkSurface = nullptr;

libs/hwui/pipeline/skia/SkiaVulkanPipeline.h

@@ -61,6 +61,7 @@ private:
     renderthread::VulkanManager& vulkanManager();
 
     renderthread::VulkanSurface* mVkSurface = nullptr;
+    sp<ANativeWindow> mNativeWindow;
 };
 
 } /* namespace skiapipeline */

libs/hwui/tests/unit/SkiaPipelineTests.cpp

@@ -404,7 +404,9 @@ RENDERTHREAD_SKIA_PIPELINE_TEST(SkiaPipeline, context_lost) {
     EXPECT_TRUE(pipeline->isSurfaceReady());
     renderThread.destroyRenderingContext();
     EXPECT_FALSE(pipeline->isSurfaceReady());
-    LOG_ALWAYS_FATAL_IF(pipeline->isSurfaceReady());
+
+    pipeline->makeCurrent();
+    EXPECT_TRUE(pipeline->isSurfaceReady());
 }
 
 RENDERTHREAD_SKIA_PIPELINE_TEST(SkiaPipeline, pictureCallback) {