Infrastructure for temportarily relinquishing GPU resources.

content/browser/gpu/gpu_process_host.cc

 // Copyright (c) 2012 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 "content/browser/gpu/gpu_process_host.h"
 
 #include "base/base64.h"
 #include "base/base_switches.h"
 #include "base/basictypes.h"
 #include "base/bind.h"
@@ skipping 138 matching lines @@
                                       ChildProcessHost* host)
 #if defined(OS_WIN)
       : cmd_line_(cmd_line) {}
 #elif defined(OS_POSIX)
       : ipc_fd_(host->TakeClientFileDescriptor()) {}
 #endif
 
   ~GpuSandboxedProcessLauncherDelegate() override {}
 
 #if defined(OS_WIN)
-  virtual bool ShouldSandbox() override {
+  bool ShouldSandbox() override {
     bool sandbox = !cmd_line_->HasSwitch(switches::kDisableGpuSandbox);
-    if(! sandbox) {
+    if (!sandbox) {
       DVLOG(1) << "GPU sandbox is disabled";
     }
     return sandbox;
   }
 
-  virtual void PreSandbox(bool* disable_default_policy,
+  void PreSandbox(bool* disable_default_policy,
                           base::FilePath* exposed_dir) override {
     *disable_default_policy = true;
   }
 
   // For the GPU process we gotten as far as USER_LIMITED. The next level
   // which is USER_RESTRICTED breaks both the DirectX backend and the OpenGL
   // backend. Note that the GPU process is connected to the interactive
   // desktop.
   virtual void PreSpawnTarget(sandbox::TargetPolicy* policy,
                               bool* success) {
@@ skipping 163 matching lines @@
                               CauseForGpuLaunch cause,
                               IPC::Message* message) {
   if (!BrowserThread::PostTask(
           BrowserThread::IO, FROM_HERE,
           base::Bind(
               &SendGpuProcessMessage, kind, cause, message))) {
     delete message;
   }
 }
 
+// static
+void GpuProcessHost::RelinquishResources(const RelinquishCallback& callback) {
+  if (!BrowserThread::CurrentlyOn(BrowserThread::IO)) {
+    BrowserThread::PostTask(
+        BrowserThread::IO,
+        FROM_HERE,
+        base::Bind(&GpuProcessHost::RelinquishResources, callback));
+    return;
+  }
+  GpuProcessHost* host = GpuProcessHost::Get(GPU_PROCESS_KIND_SANDBOXED,
+                                             CAUSE_FOR_GPU_LAUNCH_NO_LAUNCH);
+  if (!host ||
+      !BrowserThread::PostTask(BrowserThread::IO, FROM_HERE,
+          base::Bind(&GpuProcessHost::RelinquishResourcesInternal,
+                     base::Unretained(host),

[jbauman, 2014/11/12 01:47:28]

I don't think this use of base::Unretained is safe. Instead just call
host->RelinquishResourcesInternal directly.

[GusFernandez, 2014/11/15 02:11:56]

This is now completely re-written and simplified in gpu_process_host_ui_shim.cc

+                     callback))) {
+    callback.Run(false);
+  }
+}
+
+void GpuProcessHost::RelinquishResourcesInternal(
+    const RelinquishCallback& callback) {
+  if (gpu_enabled()) {
+    relinquish_callback_ = callback;

[jbauman, 2014/11/12 01:47:28]

DCHECK(relinquish_callback_.is_null()); before this.

[GusFernandez, 2014/11/15 02:11:56]

Done.

+    // We send two messages to the GPU process. the first is handled by
+    // GpuChannelManager to release the default_offscreen_surface which
+    // may hold a pointer to the EGL display which is about to be released.
+    // The second is handled by the Ozone platform to release all remaining
+    // OpenGL and EGL resources. It sendsback a ResourcesRelinquished message
+    // once this is completed and it is safe for an external process to
+    // access the GPU.
+    SendGpuProcessMessage(GPU_PROCESS_KIND_SANDBOXED,
+                          CAUSE_FOR_GPU_LAUNCH_NO_LAUNCH,
+                          new GpuMsg_DeleteDefaultOffscreenSurface);
+#if defined(USE_OZONE)
+    SendGpuProcessMessage(GPU_PROCESS_KIND_SANDBOXED,
+                          CAUSE_FOR_GPU_LAUNCH_NO_LAUNCH,
+                          new GpuMsg_RelinquishDisplay);
+    return;
+#endif
+  }
+  BrowserThread::PostTask(BrowserThread::UI,
+                          FROM_HERE,
+                          base::Bind(callback, false));
+}
+
+void GpuProcessHost::OnResourcesRelinquished(bool success) {
+  BrowserThread::PostTask(BrowserThread::UI,
+                          FROM_HERE,
+                          base::Bind(relinquish_callback_, success));
+}

[jbauman, 2014/11/12 01:47:28]

reset relinquish_callback_ here. Also you should do this in
GpuProcessHost::~GpuProcessHost as well.

[GusFernandez, 2014/11/15 02:11:56]

Done.

+
 GpuMainThreadFactoryFunction g_gpu_main_thread_factory = NULL;
 
 void GpuProcessHost::RegisterGpuMainThreadFactory(
     GpuMainThreadFactoryFunction create) {
   g_gpu_main_thread_factory = create;
 }
 
 // static
 GpuProcessHost* GpuProcessHost::FromID(int host_id) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
@@ skipping 213 matching lines @@
     IPC_MESSAGE_HANDLER(GpuHostMsg_GpuMemoryUmaStats,
                         OnGpuMemoryUmaStatsReceived)
 #if defined(OS_MACOSX)
     IPC_MESSAGE_HANDLER_GENERIC(GpuHostMsg_AcceleratedSurfaceBuffersSwapped,
                                 OnAcceleratedSurfaceBuffersSwapped(message))
 #endif
     IPC_MESSAGE_HANDLER(GpuHostMsg_DestroyChannel,
                         OnDestroyChannel)
     IPC_MESSAGE_HANDLER(GpuHostMsg_CacheShader,
                         OnCacheShader)
+    IPC_MESSAGE_HANDLER(GpuHostMsg_ResourceRelinquished,
+                        OnResourcesRelinquished)
 
     IPC_MESSAGE_UNHANDLED(RouteOnUIThread(message))
   IPC_END_MESSAGE_MAP()
 
   return true;
 }
 
 void GpuProcessHost::OnChannelConnected(int32 peer_pid) {
   TRACE_EVENT0("gpu", "GpuProcessHost::OnChannelConnected");
 
@@ skipping 476 matching lines @@
   TRACE_EVENT0("gpu", "GpuProcessHost::OnCacheShader");
   ClientIdToShaderCacheMap::iterator iter =
       client_id_to_shader_cache_.find(client_id);
   // If the cache doesn't exist then this is an off the record profile.
   if (iter == client_id_to_shader_cache_.end())
     return;
   iter->second->Cache(GetShaderPrefixKey() + ":" + key, shader);
 }
 
 }  // namespace content