Fix gpu command buffer use after free by GrContext

content/browser/gpu/gpu_ipc_browsertests.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/command_line.h"
 #include "base/run_loop.h"
 #include "content/browser/gpu/browser_gpu_channel_host_factory.h"
 #include "content/browser/gpu/gpu_process_host_ui_shim.h"
 #include "content/common/gpu/client/context_provider_command_buffer.h"
 #include "content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.h"
 #include "content/common/gpu/gpu_process_launch_causes.h"
 #include "content/public/browser/gpu_data_manager.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/test/content_browser_test.h"
 #include "gpu/blink/webgraphicscontext3d_in_process_command_buffer_impl.h"
+#include "third_party/skia/include/core/SkCanvas.h"
+#include "third_party/skia/include/core/SkSurface.h"
+#include "third_party/skia/include/gpu/GrContext.h"
 #include "ui/gl/gl_switches.h"
 
 namespace {
 
 using content::WebGraphicsContext3DCommandBufferImpl;
 
 const content::CauseForGpuLaunch kInitCause =
     content::
         CAUSE_FOR_GPU_LAUNCH_WEBGRAPHICSCONTEXT3DCOMMANDBUFFERIMPL_INITIALIZE;
 
@@ skipping 164 matching lines @@
       kInitCause,
       base::Bind(&BrowserGpuChannelHostFactoryTest::Signal, &event));
   EXPECT_TRUE(event);
   EXPECT_EQ(gpu_channel.get(), GetGpuChannel());
 }
 #endif
 
 // Test fails on Chromeos + Mac, flaky on Windows because UI Compositor
 // establishes a GPU channel.
 #if defined(OS_LINUX) && !defined(OS_CHROMEOS)
+#define MAYBE_GrContextKeepsGpuChannelAlive GrContextKeepsGpuChannelAlive
+#else
+#define MAYBE_GrContextKeepsGpuChannelAlive \
+    DISABLED_GrContextKeepsGpuChannelAlive
+#endif
+IN_PROC_BROWSER_TEST_F(BrowserGpuChannelHostFactoryTest,
+                       MAYBE_GrContextKeepsGpuChannelAlive) {

[Ken Russell (switch to Gerrit), 2015/11/11 19:16:51]

It looks like this new test's failing on some of the trybots.

+  // Test for crbug.com/551143
+  // This test verifies that holding a reference to the GrContext created by
+  // a ContextProviderCommandBuffer will keep the gpu channel alive after the
+  // provider has been destroyed. Without this behavior, user code would have
+  // to be careful to destroy objects in the right order to avoid using freed
+  // memory as a function pointer in the GrContext's GrGLInterface instance.
+  DCHECK(!IsChannelEstablished());
+  EstablishAndWait();
+
+  // Step 2: verify that holding onto the provider's GrContext will
+  // retain the host after provider is destroyed.
+  scoped_refptr<ContextProviderCommandBuffer> provider =
+      ContextProviderCommandBuffer::Create(CreateContext(),
+                                           OFFSCREEN_CONTEXT_FOR_TESTING);
+  EXPECT_TRUE(provider->BindToCurrentThread());
+
+  skia::RefPtr<GrContext> gr_context = skia::SharePtr(provider->GrContext());
+  provider = nullptr;
+
+  SkImageInfo info = SkImageInfo::MakeN32Premul(1, 1);
+  skia::RefPtr<SkSurface> surface = skia::AdoptRef(SkSurface::NewRenderTarget(
+      gr_context.get(), SkSurface::kNo_Budgeted, info));
+  gr_context = nullptr;
+
+  // use the canvas after the provider and grcontext have been locally
+  // unref'ed. This should work just fine thanks to SkSurface_Gpu ref'ing
+  // the GrContext, which is ref'ing the GrGLInterfaceForWebGraphicsContext3D,
+  // which owns the commandbuffer instance.
+  surface->getCanvas()->clear(SK_ColorGREEN);
+  SkColor readback;
+  surface->getCanvas()->readPixels(info, &readback, sizeof(SkColor), 0, 0);
+  EXPECT_EQ(SK_ColorGREEN, readback);
+}
+
+// Test fails on Chromeos + Mac, flaky on Windows because UI Compositor
+// establishes a GPU channel.
+#if defined(OS_LINUX) && !defined(OS_CHROMEOS)
 #define MAYBE_CrashAndRecover
 #else
 #define MAYBE_CrashAndRecover DISABLED_CrashAndRecover
 #endif
 IN_PROC_BROWSER_TEST_F(BrowserGpuChannelHostFactoryTest,
                        MAYBE_CrashAndRecover) {
   DCHECK(!IsChannelEstablished());
   EstablishAndWait();
   scoped_refptr<GpuChannelHost> host = GetGpuChannel();
 
@@ skipping 12 matching lines @@
   shim->SimulateCrash();
   run_loop.Run();
 
   EXPECT_EQ(1, counter);
   EXPECT_FALSE(IsChannelEstablished());
   EstablishAndWait();
   EXPECT_TRUE(IsChannelEstablished());
 }
 
 }  // namespace content