ppapi/proxy/ppb_message_loop_proxy.cc - chromium/src.git - Git at Google

 // 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 "ppapi/proxy/ppb_message_loop_proxy.h"

 #include <stddef.h>

 #include <vector>

 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/compiler_specific.h"
 #include "base/logging.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "ppapi/c/pp_errors.h"
 #include "ppapi/c/ppb_message_loop.h"
 #include "ppapi/proxy/plugin_dispatcher.h"
 #include "ppapi/proxy/plugin_globals.h"
 #include "ppapi/shared_impl/proxy_lock.h"
 #include "ppapi/thunk/enter.h"

 using ppapi::thunk::PPB_MessageLoop_API;

 namespace ppapi {
 namespace proxy {

 namespace {
 typedef thunk::EnterResource<PPB_MessageLoop_API> EnterMessageLoop;
 }

 MessageLoopResource::MessageLoopResource(PP_Instance instance)
     : MessageLoopShared(instance),
       nested_invocations_(0),
       destroyed_(false),
       should_destroy_(false),
       is_main_thread_loop_(false),
       currently_handling_blocking_message_(false) {
 }

 MessageLoopResource::MessageLoopResource(ForMainThread for_main_thread)
     : MessageLoopShared(for_main_thread),
       nested_invocations_(0),
       destroyed_(false),
       should_destroy_(false),
       is_main_thread_loop_(true),
       currently_handling_blocking_message_(false) {
   // We attach the main thread immediately. We can't use AttachToCurrentThread,
   // because the MessageLoop already exists.

   // This must be called only once, so the slot must be empty.
   CHECK(!PluginGlobals::Get()->msg_loop_slot());
   // We don't add a reference for TLS here, so we don't release it. Instead,
   // this loop is owned by PluginGlobals. Contrast with AttachToCurrentThread
   // where we register ReleaseMessageLoop with TLS and call AddRef.
   base::ThreadLocalStorage::Slot* slot = new base::ThreadLocalStorage::Slot();
   PluginGlobals::Get()->set_msg_loop_slot(slot);

   slot->Set(this);

   task_runner_ = base::ThreadTaskRunnerHandle::Get();
 }


 MessageLoopResource::~MessageLoopResource() {
 }

 PPB_MessageLoop_API* MessageLoopResource::AsPPB_MessageLoop_API() {
   return this;
 }

 int32_t MessageLoopResource::AttachToCurrentThread() {
   if (is_main_thread_loop_)
     return PP_ERROR_INPROGRESS;

   PluginGlobals* globals = PluginGlobals::Get();

   base::ThreadLocalStorage::Slot* slot = globals->msg_loop_slot();
   if (!slot) {
     slot = new base::ThreadLocalStorage::Slot(&ReleaseMessageLoop);
     globals->set_msg_loop_slot(slot);
   } else {
     if (slot->Get())
       return PP_ERROR_INPROGRESS;
   }
   // TODO(dmichael) check that the current thread can support a message loop.

   // Take a ref to the MessageLoop on behalf of the TLS. Note that this is an
   // internal ref and not a plugin ref so the plugin can't accidentally
   // release it. This is released by ReleaseMessageLoop().
   AddRef();
   slot->Set(this);

   loop_.reset(new base::MessageLoop);
   task_runner_ = base::ThreadTaskRunnerHandle::Get();

   // Post all pending work to the message loop.
   for (size_t i = 0; i < pending_tasks_.size(); i++) {
     const TaskInfo& info = pending_tasks_[i];
     PostClosure(info.from_here, info.closure, info.delay_ms);
   }
   pending_tasks_.clear();

   return PP_OK;
 }

 int32_t MessageLoopResource::Run() {
   if (!IsCurrent())
     return PP_ERROR_WRONG_THREAD;
   if (is_main_thread_loop_)
     return PP_ERROR_INPROGRESS;

   base::RunLoop* previous_run_loop = run_loop_;
   base::RunLoop run_loop;
   run_loop_ = &run_loop;

   nested_invocations_++;
   CallWhileUnlocked(
       base::Bind(&base::RunLoop::Run, base::Unretained(run_loop_)));
   nested_invocations_--;

   run_loop_ = previous_run_loop;

   if (should_destroy_ && nested_invocations_ == 0) {
     task_runner_ = NULL;
     loop_.reset();
     destroyed_ = true;
   }
   return PP_OK;
 }

 int32_t MessageLoopResource::PostWork(PP_CompletionCallback callback,
                                       int64_t delay_ms) {
   if (!callback.func)
     return PP_ERROR_BADARGUMENT;
   if (destroyed_)
     return PP_ERROR_FAILED;
   PostClosure(FROM_HERE,
               base::Bind(callback.func, callback.user_data,
                          static_cast<int32_t>(PP_OK)),
               delay_ms);
   return PP_OK;
 }

 int32_t MessageLoopResource::PostQuit(PP_Bool should_destroy) {
   if (is_main_thread_loop_)
     return PP_ERROR_WRONG_THREAD;

   if (PP_ToBool(should_destroy))
     should_destroy_ = true;

   if (IsCurrent() && nested_invocations_ > 0) {
     run_loop_->QuitWhenIdle();
   } else {
     PostClosure(FROM_HERE, base::Bind(&MessageLoopResource::QuitRunLoopWhenIdle,
                                       Unretained(this)),
                 0);
   }
   return PP_OK;
 }

 // static
 MessageLoopResource* MessageLoopResource::GetCurrent() {
   PluginGlobals* globals = PluginGlobals::Get();
   if (!globals->msg_loop_slot())
     return NULL;
   return reinterpret_cast<MessageLoopResource*>(
       globals->msg_loop_slot()->Get());
 }

 void MessageLoopResource::DetachFromThread() {
   // Note that the message loop must be destroyed on the thread it was created
   // on.
   task_runner_ = NULL;
   loop_.reset();

   // Cancel out the AddRef in AttachToCurrentThread().
   Release();
   // DANGER: may delete this.
 }

 bool MessageLoopResource::IsCurrent() const {
   PluginGlobals* globals = PluginGlobals::Get();
   if (!globals->msg_loop_slot())
     return false;  // Can't be current if there's nothing in the slot.
   return static_cast<const void*>(globals->msg_loop_slot()->Get()) ==
          static_cast<const void*>(this);
 }

 void MessageLoopResource::PostClosure(
     const tracked_objects::Location& from_here,
     const base::Closure& closure,
     int64_t delay_ms) {
   if (task_runner_.get()) {
     task_runner_->PostDelayedTask(from_here, closure,
                                   base::TimeDelta::FromMilliseconds(delay_ms));
   } else {
     TaskInfo info;
     info.from_here = FROM_HERE;
     info.closure = closure;
     info.delay_ms = delay_ms;
     pending_tasks_.push_back(info);
   }
 }

 base::SingleThreadTaskRunner* MessageLoopResource::GetTaskRunner() {
   return task_runner_.get();
 }

 bool MessageLoopResource::CurrentlyHandlingBlockingMessage() {
   return currently_handling_blocking_message_;
 }

 void MessageLoopResource::QuitRunLoopWhenIdle() {
   DCHECK(IsCurrent());
   DCHECK(run_loop_);
   run_loop_->QuitWhenIdle();
 }

 // static
 void MessageLoopResource::ReleaseMessageLoop(void* value) {
   static_cast<MessageLoopResource*>(value)->DetachFromThread();
 }

 // -----------------------------------------------------------------------------

 PP_Resource Create(PP_Instance instance) {
   ProxyAutoLock lock;
   // Validate the instance.
   PluginDispatcher* dispatcher = PluginDispatcher::GetForInstance(instance);
   if (!dispatcher)
     return 0;
   return (new MessageLoopResource(instance))->GetReference();
 }

 PP_Resource GetForMainThread() {
   ProxyAutoLock lock;
   return PluginGlobals::Get()->loop_for_main_thread()->GetReference();
 }

 PP_Resource GetCurrent() {
   ProxyAutoLock lock;
   Resource* resource = MessageLoopResource::GetCurrent();
   if (resource)
     return resource->GetReference();
   return 0;
 }

 int32_t AttachToCurrentThread(PP_Resource message_loop) {
   EnterMessageLoop enter(message_loop, true);
   if (enter.succeeded())
     return enter.object()->AttachToCurrentThread();
   return PP_ERROR_BADRESOURCE;
 }

 int32_t Run(PP_Resource message_loop) {
   EnterMessageLoop enter(message_loop, true);
   if (enter.succeeded())
     return enter.object()->Run();
   return PP_ERROR_BADRESOURCE;
 }

 int32_t PostWork(PP_Resource message_loop,
                  PP_CompletionCallback callback,
                  int64_t delay_ms) {
   EnterMessageLoop enter(message_loop, true);
   if (enter.succeeded())
     return enter.object()->PostWork(callback, delay_ms);
   return PP_ERROR_BADRESOURCE;
 }

 int32_t PostQuit(PP_Resource message_loop, PP_Bool should_destroy) {
   EnterMessageLoop enter(message_loop, true);
   if (enter.succeeded())
     return enter.object()->PostQuit(should_destroy);
   return PP_ERROR_BADRESOURCE;
 }

 const PPB_MessageLoop_1_0 ppb_message_loop_interface = {
   &Create,
   &GetForMainThread,
   &GetCurrent,
   &AttachToCurrentThread,
   &Run,
   &PostWork,
   &PostQuit
 };

 PPB_MessageLoop_Proxy::PPB_MessageLoop_Proxy(Dispatcher* dispatcher)
     : InterfaceProxy(dispatcher) {
 }

 PPB_MessageLoop_Proxy::~PPB_MessageLoop_Proxy() {
 }

 // static
 const PPB_MessageLoop_1_0* PPB_MessageLoop_Proxy::GetInterface() {
   return &ppb_message_loop_interface;
 }

 }  // namespace proxy
 }  // namespace ppapi
	// 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 "ppapi/proxy/ppb_message_loop_proxy.h"

	#include <stddef.h>

	#include <vector>

	#include "base/bind.h"
	#include "base/bind_helpers.h"
	#include "base/compiler_specific.h"
	#include "base/logging.h"
	#include "base/threading/thread_task_runner_handle.h"
	#include "ppapi/c/pp_errors.h"
	#include "ppapi/c/ppb_message_loop.h"
	#include "ppapi/proxy/plugin_dispatcher.h"
	#include "ppapi/proxy/plugin_globals.h"
	#include "ppapi/shared_impl/proxy_lock.h"
	#include "ppapi/thunk/enter.h"

	using ppapi::thunk::PPB_MessageLoop_API;

	namespace ppapi {
	namespace proxy {

	namespace {
	typedef thunk::EnterResource<PPB_MessageLoop_API> EnterMessageLoop;
	}

	MessageLoopResource::MessageLoopResource(PP_Instance instance)
	: MessageLoopShared(instance),
	nested_invocations_(0),
	destroyed_(false),
	should_destroy_(false),
	is_main_thread_loop_(false),
	currently_handling_blocking_message_(false) {
	}

	MessageLoopResource::MessageLoopResource(ForMainThread for_main_thread)
	: MessageLoopShared(for_main_thread),
	nested_invocations_(0),
	destroyed_(false),
	should_destroy_(false),
	is_main_thread_loop_(true),
	currently_handling_blocking_message_(false) {
	// We attach the main thread immediately. We can't use AttachToCurrentThread,
	// because the MessageLoop already exists.

	// This must be called only once, so the slot must be empty.
	CHECK(!PluginGlobals::Get()->msg_loop_slot());
	// We don't add a reference for TLS here, so we don't release it. Instead,
	// this loop is owned by PluginGlobals. Contrast with AttachToCurrentThread
	// where we register ReleaseMessageLoop with TLS and call AddRef.
	base::ThreadLocalStorage::Slot* slot = new base::ThreadLocalStorage::Slot();
	PluginGlobals::Get()->set_msg_loop_slot(slot);

	slot->Set(this);

	task_runner_ = base::ThreadTaskRunnerHandle::Get();
	}


	MessageLoopResource::~MessageLoopResource() {
	}

	PPB_MessageLoop_API* MessageLoopResource::AsPPB_MessageLoop_API() {
	return this;
	}

	int32_t MessageLoopResource::AttachToCurrentThread() {
	if (is_main_thread_loop_)
	return PP_ERROR_INPROGRESS;

	PluginGlobals* globals = PluginGlobals::Get();

	base::ThreadLocalStorage::Slot* slot = globals->msg_loop_slot();
	if (!slot) {
	slot = new base::ThreadLocalStorage::Slot(&ReleaseMessageLoop);
	globals->set_msg_loop_slot(slot);
	} else {
	if (slot->Get())
	return PP_ERROR_INPROGRESS;
	}
	// TODO(dmichael) check that the current thread can support a message loop.

	// Take a ref to the MessageLoop on behalf of the TLS. Note that this is an
	// internal ref and not a plugin ref so the plugin can't accidentally
	// release it. This is released by ReleaseMessageLoop().
	AddRef();
	slot->Set(this);

	loop_.reset(new base::MessageLoop);
	task_runner_ = base::ThreadTaskRunnerHandle::Get();

	// Post all pending work to the message loop.
	for (size_t i = 0; i < pending_tasks_.size(); i++) {
	const TaskInfo& info = pending_tasks_[i];
	PostClosure(info.from_here, info.closure, info.delay_ms);
	}
	pending_tasks_.clear();

	return PP_OK;
	}

	int32_t MessageLoopResource::Run() {
	if (!IsCurrent())
	return PP_ERROR_WRONG_THREAD;
	if (is_main_thread_loop_)
	return PP_ERROR_INPROGRESS;

	base::RunLoop* previous_run_loop = run_loop_;
	base::RunLoop run_loop;
	run_loop_ = &run_loop;

	nested_invocations_++;
	CallWhileUnlocked(
	base::Bind(&base::RunLoop::Run, base::Unretained(run_loop_)));
	nested_invocations_--;

	run_loop_ = previous_run_loop;

	if (should_destroy_ && nested_invocations_ == 0) {
	task_runner_ = NULL;
	loop_.reset();
	destroyed_ = true;
	}
	return PP_OK;
	}

	int32_t MessageLoopResource::PostWork(PP_CompletionCallback callback,
	int64_t delay_ms) {
	if (!callback.func)
	return PP_ERROR_BADARGUMENT;
	if (destroyed_)
	return PP_ERROR_FAILED;
	PostClosure(FROM_HERE,
	base::Bind(callback.func, callback.user_data,
	static_cast<int32_t>(PP_OK)),
	delay_ms);
	return PP_OK;
	}

	int32_t MessageLoopResource::PostQuit(PP_Bool should_destroy) {
	if (is_main_thread_loop_)
	return PP_ERROR_WRONG_THREAD;

	if (PP_ToBool(should_destroy))
	should_destroy_ = true;

	if (IsCurrent() && nested_invocations_ > 0) {
	run_loop_->QuitWhenIdle();
	} else {
	PostClosure(FROM_HERE, base::Bind(&MessageLoopResource::QuitRunLoopWhenIdle,
	Unretained(this)),
	0);
	}
	return PP_OK;
	}

	// static
	MessageLoopResource* MessageLoopResource::GetCurrent() {
	PluginGlobals* globals = PluginGlobals::Get();
	if (!globals->msg_loop_slot())
	return NULL;
	return reinterpret_cast<MessageLoopResource*>(
	globals->msg_loop_slot()->Get());
	}

	void MessageLoopResource::DetachFromThread() {
	// Note that the message loop must be destroyed on the thread it was created
	// on.
	task_runner_ = NULL;
	loop_.reset();

	// Cancel out the AddRef in AttachToCurrentThread().
	Release();
	// DANGER: may delete this.
	}

	bool MessageLoopResource::IsCurrent() const {
	PluginGlobals* globals = PluginGlobals::Get();
	if (!globals->msg_loop_slot())
	return false; // Can't be current if there's nothing in the slot.
	return static_cast<const void*>(globals->msg_loop_slot()->Get()) ==
	static_cast<const void*>(this);
	}

	void MessageLoopResource::PostClosure(
	const tracked_objects::Location& from_here,
	const base::Closure& closure,
	int64_t delay_ms) {
	if (task_runner_.get()) {
	task_runner_->PostDelayedTask(from_here, closure,
	base::TimeDelta::FromMilliseconds(delay_ms));
	} else {
	TaskInfo info;
	info.from_here = FROM_HERE;
	info.closure = closure;
	info.delay_ms = delay_ms;
	pending_tasks_.push_back(info);
	}
	}

	base::SingleThreadTaskRunner* MessageLoopResource::GetTaskRunner() {
	return task_runner_.get();
	}

	bool MessageLoopResource::CurrentlyHandlingBlockingMessage() {
	return currently_handling_blocking_message_;
	}

	void MessageLoopResource::QuitRunLoopWhenIdle() {
	DCHECK(IsCurrent());
	DCHECK(run_loop_);
	run_loop_->QuitWhenIdle();
	}

	// static
	void MessageLoopResource::ReleaseMessageLoop(void* value) {
	static_cast<MessageLoopResource*>(value)->DetachFromThread();
	}

	// -----------------------------------------------------------------------------

	PP_Resource Create(PP_Instance instance) {
	ProxyAutoLock lock;
	// Validate the instance.
	PluginDispatcher* dispatcher = PluginDispatcher::GetForInstance(instance);
	if (!dispatcher)
	return 0;
	return (new MessageLoopResource(instance))->GetReference();
	}

	PP_Resource GetForMainThread() {
	ProxyAutoLock lock;
	return PluginGlobals::Get()->loop_for_main_thread()->GetReference();
	}

	PP_Resource GetCurrent() {
	ProxyAutoLock lock;
	Resource* resource = MessageLoopResource::GetCurrent();
	if (resource)
	return resource->GetReference();
	return 0;
	}

	int32_t AttachToCurrentThread(PP_Resource message_loop) {
	EnterMessageLoop enter(message_loop, true);
	if (enter.succeeded())
	return enter.object()->AttachToCurrentThread();
	return PP_ERROR_BADRESOURCE;
	}

	int32_t Run(PP_Resource message_loop) {
	EnterMessageLoop enter(message_loop, true);
	if (enter.succeeded())
	return enter.object()->Run();
	return PP_ERROR_BADRESOURCE;
	}

	int32_t PostWork(PP_Resource message_loop,
	PP_CompletionCallback callback,
	int64_t delay_ms) {
	EnterMessageLoop enter(message_loop, true);
	if (enter.succeeded())
	return enter.object()->PostWork(callback, delay_ms);
	return PP_ERROR_BADRESOURCE;
	}

	int32_t PostQuit(PP_Resource message_loop, PP_Bool should_destroy) {
	EnterMessageLoop enter(message_loop, true);
	if (enter.succeeded())
	return enter.object()->PostQuit(should_destroy);
	return PP_ERROR_BADRESOURCE;
	}

	const PPB_MessageLoop_1_0 ppb_message_loop_interface = {
	&Create,
	&GetForMainThread,
	&GetCurrent,
	&AttachToCurrentThread,
	&Run,
	&PostWork,
	&PostQuit
	};

	PPB_MessageLoop_Proxy::PPB_MessageLoop_Proxy(Dispatcher* dispatcher)
	: InterfaceProxy(dispatcher) {
	}

	PPB_MessageLoop_Proxy::~PPB_MessageLoop_Proxy() {
	}

	// static
	const PPB_MessageLoop_1_0* PPB_MessageLoop_Proxy::GetInterface() {
	return &ppb_message_loop_interface;
	}

	} // namespace proxy
	} // namespace ppapi