gpu: Use mojom API for recording log messages to the host.

services/ui/gpu/gpu_service.cc

 // Copyright 2016 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 "services/ui/gpu/gpu_service.h"
 
 #include "base/bind.h"
 #include "base/debug/crash_logging.h"
+#include "base/lazy_instance.h"
 #include "base/memory/shared_memory.h"
 #include "base/message_loop/message_loop.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "build/build_config.h"
 #include "cc/output/in_process_context_provider.h"
 #include "gpu/command_buffer/client/gpu_memory_buffer_manager.h"
 #include "gpu/command_buffer/service/gpu_switches.h"
 #include "gpu/command_buffer/service/sync_point_manager.h"
 #include "gpu/config/gpu_info_collector.h"
 #include "gpu/config/gpu_switches.h"
@@ skipping 17 matching lines @@
 #include "ui/gl/init/gl_factory.h"
 #include "url/gurl.h"
 
 #if defined(OS_ANDROID)
 #include "base/android/throw_uncaught_exception.h"
 #include "media/gpu/avda_codec_allocator.h"
 #endif
 
 namespace ui {
 
+namespace {
+
+static base::LazyInstance<base::Callback<
+    void(int severity, size_t message_start, const std::string& message)>>::
+    Leaky g_log_callback = LAZY_INSTANCE_INITIALIZER;
+
+bool GpuLogMessageHandler(int severity,
+                          const char* file,
+                          int line,
+                          size_t message_start,
+                          const std::string& message) {
+  g_log_callback.Get().Run(severity, message_start, message);
+  return false;
+}
+
+}  // namespace
+
 GpuService::GpuService(const gpu::GPUInfo& gpu_info,
                        std::unique_ptr<gpu::GpuWatchdogThread> watchdog_thread,
                        gpu::GpuMemoryBufferFactory* gpu_memory_buffer_factory,
                        scoped_refptr<base::SingleThreadTaskRunner> io_runner,
                        const gpu::GpuFeatureInfo& gpu_feature_info)
     : io_runner_(std::move(io_runner)),
       shutdown_event_(base::WaitableEvent::ResetPolicy::MANUAL,
                       base::WaitableEvent::InitialState::NOT_SIGNALED),
       watchdog_thread_(std::move(watchdog_thread)),
       gpu_memory_buffer_factory_(gpu_memory_buffer_factory),
       gpu_info_(gpu_info),
       gpu_feature_info_(gpu_feature_info),
       sync_point_manager_(nullptr) {}
 
 GpuService::~GpuService() {
+  logging::SetLogMessageHandler(nullptr);
+  g_log_callback.Get() =
+      base::Callback<void(int, size_t, const std::string&)>();
   bindings_.CloseAllBindings();
   media_gpu_channel_manager_.reset();
   gpu_channel_manager_.reset();
   owned_sync_point_manager_.reset();
 
   // Signal this event before destroying the child process.  That way all
   // background threads can cleanup.
   // For example, in the renderer the RenderThread instances will be able to
   // notice shutdown before the render process begins waiting for them to exit.
   shutdown_event_.Signal();
@@ skipping 10 matching lines @@
   gpu_preferences_ = preferences;
   gpu_info_.video_decode_accelerator_capabilities =
       media::GpuVideoDecodeAccelerator::GetCapabilities(gpu_preferences_);
   gpu_info_.video_encode_accelerator_supported_profiles =
       media::GpuVideoEncodeAccelerator::GetSupportedProfiles(gpu_preferences_);
   gpu_info_.jpeg_decode_accelerator_supported =
       media::GpuJpegDecodeAcceleratorFactoryProvider::
           IsAcceleratedJpegDecodeSupported();
   gpu_host_->DidInitialize(gpu_info_);
 
+  if (!in_host_process_) {
+    // The global callback is reset from the dtor. So Unretained() here is safe.
+    // Note that the callback can be called from any thread. Consequently, the
+    // callback cannot use a WeakPtr.
+    g_log_callback.Get() =
+        base::Bind(&GpuService::RecordLogMessage, base::Unretained(this),
+                   base::ThreadTaskRunnerHandle::Get());

[piman, 2017/03/20 21:20:26]

So, this has different properties than the previous code, which used the
ChildThread's thread_safe_sender() which sent things without hopping to the GPU
main thread. In particular this means that if the GPU main thread is blocked, we
won't get log messages - in particular those coming from the GpuWatchdogThread
before it forces a crash. Is there any way to keep that property?

[sadrul, 2017/03/20 21:40:17]

There is ThreadSafeInterfacePtrBase<> that I could use here instead (so I would
create a ThreadSafeGpuHostPtr out of the mojom::GpuHost object I have), but
looking at the doc [1], it looks like it would just do the thread-hop
internally. So we would still have the same issue.

[1]
https://cs.chromium.org/chromium/src/mojo/public/cpp/bindings/thread_safe_int...

[Ken Rockot(use gerrit already), 2017/03/21 00:56:01]

Well one option would be to move the GpuHostPtr to the IO thread and use a
ThreadSafeGpuHostPtr everywhere else. That would be a bummer.

I think we should probably change TSIP to do direct writes from arbitrary
threads.

That does mean existing users of TSIP would need to be updated to use some other
special-case thing, as the existing TSIP was designed to emulate
ThreadSafeSender semantics and thus requires that we PostTask to some target
TaskRunner (typically the IO thread) to preserve ordering guarantees.

+    logging::SetLogMessageHandler(GpuLogMessageHandler);
+  }
+
   sync_point_manager_ = sync_point_manager;
   if (!sync_point_manager_) {
     owned_sync_point_manager_ = base::MakeUnique<gpu::SyncPointManager>();
     sync_point_manager_ = owned_sync_point_manager_.get();
   }
 
   // Defer creation of the render thread. This is to prevent it from handling
   // IPC messages before the sandbox has been enabled and all other necessary
   // initialization has succeeded.
   gpu_channel_manager_.reset(new gpu::GpuChannelManager(
       gpu_preferences_, this, watchdog_thread_.get(),
       base::ThreadTaskRunnerHandle::Get().get(), io_runner_.get(),
       shutdown_event ? shutdown_event : &shutdown_event_, sync_point_manager_,
       gpu_memory_buffer_factory_, gpu_feature_info_,
       std::move(activity_flags)));
 
   media_gpu_channel_manager_.reset(
       new media::MediaGpuChannelManager(gpu_channel_manager_.get()));
 }
 
 void GpuService::Bind(mojom::GpuServiceRequest request) {
   bindings_.AddBinding(this, std::move(request));
 }
 
+void GpuService::RecordLogMessage(
+    scoped_refptr<base::SingleThreadTaskRunner> task_runner,
+    int severity,
+    size_t message_start,
+    const std::string& str) {
+  if (!task_runner->BelongsToCurrentThread()) {
+    task_runner->PostTask(
+        FROM_HERE,
+        base::Bind(base::IgnoreResult(&GpuLogMessageHandler), severity,
+                   nullptr /* file */, 0 /* line */, message_start, str));
+    return;
+  }
+  std::string header = str.substr(0, message_start);
+  std::string message = str.substr(message_start);
+  gpu_host_->RecordLogMessage(severity, header, message);
+}
+
 void GpuService::CreateGpuMemoryBuffer(
     gfx::GpuMemoryBufferId id,
     const gfx::Size& size,
     gfx::BufferFormat format,
     gfx::BufferUsage usage,
     int client_id,
     gpu::SurfaceHandle surface_handle,
     const CreateGpuMemoryBufferCallback& callback) {
   DCHECK(CalledOnValidThread());
   callback.Run(gpu_memory_buffer_factory_->CreateGpuMemoryBuffer(
@@ skipping 195 matching lines @@
   NOTREACHED() << "Java exception not supported on this platform.";
 #endif
 }
 
 void GpuService::Stop(const StopCallback& callback) {
   base::MessageLoop::current()->QuitWhenIdle();
   callback.Run();
 }
 
 }  // namespace ui