Add Shutdown() helper to ChildThread and move all destructor logic.

r185551 changed the ordering of events in scoped_ptr<T>::reset();
specifically, callers can no longer rely on get() to return the old
value of the stored pointer during a reset(). This causes issues such as
http://crbug.com/232981. In order to break the dependency on the value
of main_thread_.get() during main_thread_.reset(), destruction of
ChildThread has been split into two parts.

BUG=233761

Review URL: https://codereview.chromium.org/13878020

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@195628 0039d316-1c4b-4281-b951-d872f2087c98

14 files changed, 35 insertions, 1 deletions

diff --git a/content/common/child_process.cc b/content/common/child_process.cc
index c66e4a4..6bfff5c 100644
--- a/content/common/child_process.cc
+++ b/content/common/child_process.cc
@@ -71,7 +71,10 @@ ChildProcess::~ChildProcess() {
 
   // Kill the main thread object before nulling child_process_, since
   // destruction code might depend on it.
-  main_thread_.reset();
+  if (main_thread_) {  // null in unittests.
+    main_thread_->Shutdown();
+    main_thread_.reset();
+  }
 
   child_process_ = NULL;
 }
diff --git a/content/common/child_thread.h b/content/common/child_thread.h
index 6664d34..ee99868 100644
--- a/content/common/child_thread.h
+++ b/content/common/child_thread.h
@@ -43,7 +43,13 @@ class CONTENT_EXPORT ChildThread : public IPC::Listener, public IPC::Sender {
   ChildThread();
   // Used for single-process mode.
   explicit ChildThread(const std::string& channel_name);
+  // ChildProcess::main_thread() is reset after Shutdown(), and before the
+  // destructor, so any subsystem that relies on ChildProcess::main_thread()
+  // must be terminated before Shutdown returns. In particular, if a subsystem
+  // has a thread that post tasks to ChildProcess::main_thread(), that thread
+  // should be joined in Shutdown().
   virtual ~ChildThread();
+  virtual void Shutdown() = 0;
 
   // IPC::Sender implementation:
   virtual bool Send(IPC::Message* msg) OVERRIDE;
diff --git a/content/gpu/gpu_child_thread.cc b/content/gpu/gpu_child_thread.cc
index 165d9dfc..24b0cd6 100644
--- a/content/gpu/gpu_child_thread.cc
+++ b/content/gpu/gpu_child_thread.cc
@@ -82,6 +82,9 @@ GpuChildThread::GpuChildThread(const std::string& channel_id)
 }
 
 GpuChildThread::~GpuChildThread() {
+}
+
+void GpuChildThread::Shutdown() {
   logging::SetLogMessageHandler(NULL);
 }
 
diff --git a/content/gpu/gpu_child_thread.h b/content/gpu/gpu_child_thread.h
index 58c6c10..0d4baeb 100644
--- a/content/gpu/gpu_child_thread.h
+++ b/content/gpu/gpu_child_thread.h
@@ -43,6 +43,8 @@ class GpuChildThread : public ChildThread {
 
   virtual ~GpuChildThread();
 
+  virtual void Shutdown() OVERRIDE;
+
   void Init(const base::Time& process_start_time);
   void StopWatchdog();
 
diff --git a/content/plugin/plugin_thread.cc b/content/plugin/plugin_thread.cc
index 9d3af8c..595bf5b 100644
--- a/content/plugin/plugin_thread.cc
+++ b/content/plugin/plugin_thread.cc
@@ -137,6 +137,9 @@ PluginThread::PluginThread()
 }
 
 PluginThread::~PluginThread() {
+}
+
+void PluginThread::Shutdown() {
   if (preloaded_plugin_module_) {
     base::UnloadNativeLibrary(preloaded_plugin_module_);
     preloaded_plugin_module_ = NULL;
diff --git a/content/plugin/plugin_thread.h b/content/plugin/plugin_thread.h
index f967126..86c9b2d 100644
--- a/content/plugin/plugin_thread.h
+++ b/content/plugin/plugin_thread.h
@@ -25,6 +25,7 @@ class PluginThread : public ChildThread {
  public:
   PluginThread();
   virtual ~PluginThread();
+  virtual void Shutdown() OVERRIDE;
 
   // Returns the one plugin thread.
   static PluginThread* current();
diff --git a/content/ppapi_plugin/ppapi_thread.cc b/content/ppapi_plugin/ppapi_thread.cc
index 006f28c..f321d59 100644
--- a/content/ppapi_plugin/ppapi_thread.cc
+++ b/content/ppapi_plugin/ppapi_thread.cc
@@ -113,6 +113,9 @@ PpapiThread::PpapiThread(const CommandLine& command_line, bool is_broker)
 }
 
 PpapiThread::~PpapiThread() {
+}
+
+void PpapiThread::Shutdown() {
   ppapi::proxy::PluginGlobals::Get()->set_plugin_proxy_delegate(NULL);
   if (plugin_entry_points_.shutdown_module)
     plugin_entry_points_.shutdown_module();
diff --git a/content/ppapi_plugin/ppapi_thread.h b/content/ppapi_plugin/ppapi_thread.h
index 5203ce1..7faff6b 100644
--- a/content/ppapi_plugin/ppapi_thread.h
+++ b/content/ppapi_plugin/ppapi_thread.h
@@ -47,6 +47,7 @@ class PpapiThread : public ChildThread,
  public:
   PpapiThread(const CommandLine& command_line, bool is_broker);
   virtual ~PpapiThread();
+  virtual void Shutdown() OVERRIDE;
 
  private:
   // Make sure the enum list in tools/histogram/histograms.xml is updated with
diff --git a/content/renderer/render_thread_impl.cc b/content/renderer/render_thread_impl.cc
index 81613eb..5d43940 100644
--- a/content/renderer/render_thread_impl.cc
+++ b/content/renderer/render_thread_impl.cc
@@ -413,6 +413,9 @@ void RenderThreadImpl::Init() {
 }
 
 RenderThreadImpl::~RenderThreadImpl() {
+}
+
+void RenderThreadImpl::Shutdown() {
   FOR_EACH_OBSERVER(
       RenderProcessObserver, observers_, OnRenderProcessShutdown());
 
diff --git a/content/renderer/render_thread_impl.h b/content/renderer/render_thread_impl.h
index 4708c22..a92ec60 100644
--- a/content/renderer/render_thread_impl.h
+++ b/content/renderer/render_thread_impl.h
@@ -108,6 +108,7 @@ class CONTENT_EXPORT RenderThreadImpl : public RenderThread,
   // Constructor that's used when running in single process mode.
   explicit RenderThreadImpl(const std::string& channel_name);
   virtual ~RenderThreadImpl();
+  virtual void Shutdown() OVERRIDE;
 
   // When initializing WebKit, ensure that any schemes needed for the content
   // module are registered properly.  Static to allow sharing with tests.
diff --git a/content/utility/utility_thread_impl.cc b/content/utility/utility_thread_impl.cc
index 4febffa..eed1704 100644
--- a/content/utility/utility_thread_impl.cc
+++ b/content/utility/utility_thread_impl.cc
@@ -45,6 +45,9 @@ UtilityThreadImpl::UtilityThreadImpl()
 }
 
 UtilityThreadImpl::~UtilityThreadImpl() {
+}
+
+void UtilityThreadImpl::Shutdown() {
   WebKit::shutdown();
 }
 
diff --git a/content/utility/utility_thread_impl.h b/content/utility/utility_thread_impl.h
index da2ffbd..31c51a1 100644
--- a/content/utility/utility_thread_impl.h
+++ b/content/utility/utility_thread_impl.h
@@ -27,6 +27,7 @@ class UtilityThreadImpl : public UtilityThread,
  public:
   UtilityThreadImpl();
   virtual ~UtilityThreadImpl();
+  virtual void Shutdown() OVERRIDE;
 
   virtual bool Send(IPC::Message* msg) OVERRIDE;
   virtual void ReleaseProcessIfNeeded() OVERRIDE;
diff --git a/content/worker/worker_thread.cc b/content/worker/worker_thread.cc
index 540212a..65083b3 100644
--- a/content/worker/worker_thread.cc
+++ b/content/worker/worker_thread.cc
@@ -73,6 +73,9 @@ WorkerThread::WorkerThread() {
 }
 
 WorkerThread::~WorkerThread() {
+}
+
+void WorkerThread::Shutdown() {
   // Shutdown in reverse of the initialization order.
   channel()->RemoveFilter(indexed_db_message_filter_.get());
   indexed_db_message_filter_ = NULL;
diff --git a/content/worker/worker_thread.h b/content/worker/worker_thread.h
index aaa78a3..bc51f49 100644
--- a/content/worker/worker_thread.h
+++ b/content/worker/worker_thread.h
@@ -23,6 +23,7 @@ class WorkerThread : public ChildThread {
  public:
   WorkerThread();
   virtual ~WorkerThread();
+  virtual void Shutdown() OVERRIDE;
 
   // Returns the one worker thread.
   static WorkerThread* current();