mojo/edk/system/dispatcher.cc - platform/external/libchrome - Gitiles

 // 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 "mojo/edk/system/dispatcher.h"

 #include "base/logging.h"
 #include "mojo/edk/system/configuration.h"
 #include "mojo/edk/system/data_pipe_consumer_dispatcher.h"
 #include "mojo/edk/system/data_pipe_producer_dispatcher.h"
 #include "mojo/edk/system/message_pipe_dispatcher.h"
 #include "mojo/edk/system/platform_handle_dispatcher.h"
 #include "mojo/edk/system/shared_buffer_dispatcher.h"

 namespace mojo {
 namespace edk {

 namespace test {

 // TODO(vtl): Maybe this should be defined in a test-only file instead.
 DispatcherTransport DispatcherTryStartTransport(Dispatcher* dispatcher) {
   return Dispatcher::HandleTableAccess::TryStartTransport(dispatcher);
 }

 }  // namespace test

 // Dispatcher ------------------------------------------------------------------

 // static
 DispatcherTransport Dispatcher::HandleTableAccess::TryStartTransport(
     Dispatcher* dispatcher) {
   DCHECK(dispatcher);

   // Our dispatcher implementations hop to IO thread on initialization, so it's
   // valid that while their RawChannel os being initialized on IO thread, the
   // dispatcher is being sent. We handle this by just acquiring the lock.

   // See comment in header for why we need this.
   dispatcher->TransportStarted();

   dispatcher->lock_.Acquire();

   // We shouldn't race with things that close dispatchers, since closing can
   // only take place either under |handle_table_lock_| or when the handle is
   // marked as busy.
   DCHECK(!dispatcher->is_closed_);

   return DispatcherTransport(dispatcher);
 }

 // static
 void Dispatcher::TransportDataAccess::StartSerialize(
     Dispatcher* dispatcher,
     size_t* max_size,
     size_t* max_platform_handles) {
   DCHECK(dispatcher);
   dispatcher->StartSerialize(max_size, max_platform_handles);
 }

 // static
 bool Dispatcher::TransportDataAccess::EndSerializeAndClose(
     Dispatcher* dispatcher,
     void* destination,
     size_t* actual_size,
     PlatformHandleVector* platform_handles) {
   DCHECK(dispatcher);
   return dispatcher->EndSerializeAndClose(destination, actual_size,
                                           platform_handles);
 }

 // static
 scoped_refptr<Dispatcher> Dispatcher::TransportDataAccess::Deserialize(
     int32_t type,
     const void* source,
     size_t size,
     PlatformHandleVector* platform_handles) {
   switch (static_cast<Dispatcher::Type>(type)) {
     case Type::UNKNOWN:
       DVLOG(2) << "Deserializing invalid handle";
       return nullptr;
     case Type::MESSAGE_PIPE:
       return scoped_refptr<Dispatcher>(MessagePipeDispatcher::Deserialize(
           source, size, platform_handles));
     case Type::DATA_PIPE_PRODUCER:
       return scoped_refptr<Dispatcher>(
           DataPipeProducerDispatcher::Deserialize(
               source, size, platform_handles));
     case Type::DATA_PIPE_CONSUMER:
       return scoped_refptr<Dispatcher>(
           DataPipeConsumerDispatcher::Deserialize(
               source, size, platform_handles));
     case Type::SHARED_BUFFER:
       return scoped_refptr<Dispatcher>(SharedBufferDispatcher::Deserialize(
           source, size, platform_handles));
     case Type::PLATFORM_HANDLE:
       return scoped_refptr<Dispatcher>(PlatformHandleDispatcher::Deserialize(
           source, size, platform_handles));
   }
   LOG(WARNING) << "Unknown dispatcher type " << type;
   return nullptr;
 }

 MojoResult Dispatcher::Close() {
   base::AutoLock locker(lock_);
   if (is_closed_)
     return MOJO_RESULT_INVALID_ARGUMENT;

   CloseNoLock();
   return MOJO_RESULT_OK;
 }

 MojoResult Dispatcher::WriteMessage(
     const void* bytes,
     uint32_t num_bytes,
     std::vector<DispatcherTransport>* transports,
     MojoWriteMessageFlags flags) {
   DCHECK(!transports ||
          (transports->size() > 0 &&
           transports->size() < GetConfiguration().max_message_num_handles));

   base::AutoLock locker(lock_);
   if (is_closed_)
     return MOJO_RESULT_INVALID_ARGUMENT;

   return WriteMessageImplNoLock(bytes, num_bytes, transports, flags);
 }

 MojoResult Dispatcher::ReadMessage(void* bytes,
                                    uint32_t* num_bytes,
                                    DispatcherVector* dispatchers,
                                    uint32_t* num_dispatchers,
                                    MojoReadMessageFlags flags) {
   DCHECK(!num_dispatchers || *num_dispatchers == 0 ||
          (dispatchers && dispatchers->empty()));

   base::AutoLock locker(lock_);
   if (is_closed_)
     return MOJO_RESULT_INVALID_ARGUMENT;

   return ReadMessageImplNoLock(bytes, num_bytes, dispatchers, num_dispatchers,
                                flags);
 }

 MojoResult Dispatcher::WriteData(const void* elements,
                                  uint32_t* num_bytes,
                                  MojoWriteDataFlags flags) {
   base::AutoLock locker(lock_);
   if (is_closed_)
     return MOJO_RESULT_INVALID_ARGUMENT;

   return WriteDataImplNoLock(elements, num_bytes, flags);
 }

 MojoResult Dispatcher::BeginWriteData(void** buffer,
                                       uint32_t* buffer_num_bytes,
                                       MojoWriteDataFlags flags) {
   base::AutoLock locker(lock_);
   if (is_closed_)
     return MOJO_RESULT_INVALID_ARGUMENT;

   return BeginWriteDataImplNoLock(buffer, buffer_num_bytes, flags);
 }

 MojoResult Dispatcher::EndWriteData(uint32_t num_bytes_written) {
   base::AutoLock locker(lock_);
   if (is_closed_)
     return MOJO_RESULT_INVALID_ARGUMENT;

   return EndWriteDataImplNoLock(num_bytes_written);
 }

 MojoResult Dispatcher::ReadData(void* elements,
                                 uint32_t* num_bytes,
                                 MojoReadDataFlags flags) {
   base::AutoLock locker(lock_);
   if (is_closed_)
     return MOJO_RESULT_INVALID_ARGUMENT;

   return ReadDataImplNoLock(elements, num_bytes, flags);
 }

 MojoResult Dispatcher::BeginReadData(const void** buffer,
                                      uint32_t* buffer_num_bytes,
                                      MojoReadDataFlags flags) {
   base::AutoLock locker(lock_);
   if (is_closed_)
     return MOJO_RESULT_INVALID_ARGUMENT;

   return BeginReadDataImplNoLock(buffer, buffer_num_bytes, flags);
 }

 MojoResult Dispatcher::EndReadData(uint32_t num_bytes_read) {
   base::AutoLock locker(lock_);
   if (is_closed_)
     return MOJO_RESULT_INVALID_ARGUMENT;

   return EndReadDataImplNoLock(num_bytes_read);
 }

 MojoResult Dispatcher::DuplicateBufferHandle(
     const MojoDuplicateBufferHandleOptions* options,
     scoped_refptr<Dispatcher>* new_dispatcher) {
   base::AutoLock locker(lock_);
   if (is_closed_)
     return MOJO_RESULT_INVALID_ARGUMENT;

   return DuplicateBufferHandleImplNoLock(options, new_dispatcher);
 }

 MojoResult Dispatcher::MapBuffer(
     uint64_t offset,
     uint64_t num_bytes,
     MojoMapBufferFlags flags,
     scoped_ptr<PlatformSharedBufferMapping>* mapping) {
   base::AutoLock locker(lock_);
   if (is_closed_)
     return MOJO_RESULT_INVALID_ARGUMENT;

   return MapBufferImplNoLock(offset, num_bytes, flags, mapping);
 }

 HandleSignalsState Dispatcher::GetHandleSignalsState() const {
   base::AutoLock locker(lock_);
   if (is_closed_)
     return HandleSignalsState();

   return GetHandleSignalsStateImplNoLock();
 }

 MojoResult Dispatcher::AddAwakable(Awakable* awakable,
                                    MojoHandleSignals signals,
                                    uintptr_t context,
                                    HandleSignalsState* signals_state) {
   base::AutoLock locker(lock_);
   if (is_closed_) {
     if (signals_state)
       *signals_state = HandleSignalsState();
     return MOJO_RESULT_INVALID_ARGUMENT;
   }

   return AddAwakableImplNoLock(awakable, signals, context, signals_state);
 }

 void Dispatcher::RemoveAwakable(Awakable* awakable,
                                 HandleSignalsState* handle_signals_state) {
   base::AutoLock locker(lock_);
   if (is_closed_) {
     if (handle_signals_state)
       *handle_signals_state = HandleSignalsState();
     return;
   }

   RemoveAwakableImplNoLock(awakable, handle_signals_state);
 }

 Dispatcher::Dispatcher() : is_closed_(false) {
 }

 Dispatcher::~Dispatcher() {
   // Make sure that |Close()| was called.
   DCHECK(is_closed_);
 }

 void Dispatcher::CancelAllAwakablesNoLock() {
   lock_.AssertAcquired();
   DCHECK(is_closed_);
   // By default, waiting isn't supported. Only dispatchers that can be waited on
   // will do something nontrivial.
 }

 void Dispatcher::CloseImplNoLock() {
   lock_.AssertAcquired();
   DCHECK(is_closed_);
   // This may not need to do anything. Dispatchers should override this to do
   // any actual close-time cleanup necessary.
 }

 MojoResult Dispatcher::WriteMessageImplNoLock(
     const void* /*bytes*/,
     uint32_t /*num_bytes*/,
     std::vector<DispatcherTransport>* /*transports*/,
     MojoWriteMessageFlags /*flags*/) {
   lock_.AssertAcquired();
   DCHECK(!is_closed_);
   // By default, not supported. Only needed for message pipe dispatchers.
   return MOJO_RESULT_INVALID_ARGUMENT;
 }

 MojoResult Dispatcher::ReadMessageImplNoLock(
     void* /*bytes*/,
     uint32_t* /*num_bytes*/,
     DispatcherVector* /*dispatchers*/,
     uint32_t* /*num_dispatchers*/,
     MojoReadMessageFlags /*flags*/) {
   lock_.AssertAcquired();
   DCHECK(!is_closed_);
   // By default, not supported. Only needed for message pipe dispatchers.
   return MOJO_RESULT_INVALID_ARGUMENT;
 }

 MojoResult Dispatcher::WriteDataImplNoLock(const void* /*elements*/,
                                            uint32_t* /*num_bytes*/,
                                            MojoWriteDataFlags /*flags*/) {
   lock_.AssertAcquired();
   DCHECK(!is_closed_);
   // By default, not supported. Only needed for data pipe dispatchers.
   return MOJO_RESULT_INVALID_ARGUMENT;
 }

 MojoResult Dispatcher::BeginWriteDataImplNoLock(
     void** /*buffer*/,
     uint32_t* /*buffer_num_bytes*/,
     MojoWriteDataFlags /*flags*/) {
   lock_.AssertAcquired();
   DCHECK(!is_closed_);
   // By default, not supported. Only needed for data pipe dispatchers.
   return MOJO_RESULT_INVALID_ARGUMENT;
 }

 MojoResult Dispatcher::EndWriteDataImplNoLock(uint32_t /*num_bytes_written*/) {
   lock_.AssertAcquired();
   DCHECK(!is_closed_);
   // By default, not supported. Only needed for data pipe dispatchers.
   return MOJO_RESULT_INVALID_ARGUMENT;
 }

 MojoResult Dispatcher::ReadDataImplNoLock(void* /*elements*/,
                                           uint32_t* /*num_bytes*/,
                                           MojoReadDataFlags /*flags*/) {
   lock_.AssertAcquired();
   DCHECK(!is_closed_);
   // By default, not supported. Only needed for data pipe dispatchers.
   return MOJO_RESULT_INVALID_ARGUMENT;
 }

 MojoResult Dispatcher::BeginReadDataImplNoLock(
     const void** /*buffer*/,
     uint32_t* /*buffer_num_bytes*/,
     MojoReadDataFlags /*flags*/) {
   lock_.AssertAcquired();
   DCHECK(!is_closed_);
   // By default, not supported. Only needed for data pipe dispatchers.
   return MOJO_RESULT_INVALID_ARGUMENT;
 }

 MojoResult Dispatcher::EndReadDataImplNoLock(uint32_t /*num_bytes_read*/) {
   lock_.AssertAcquired();
   DCHECK(!is_closed_);
   // By default, not supported. Only needed for data pipe dispatchers.
   return MOJO_RESULT_INVALID_ARGUMENT;
 }

 MojoResult Dispatcher::DuplicateBufferHandleImplNoLock(
     const MojoDuplicateBufferHandleOptions* /*options*/,
     scoped_refptr<Dispatcher>* /*new_dispatcher*/) {
   lock_.AssertAcquired();
   DCHECK(!is_closed_);
   // By default, not supported. Only needed for buffer dispatchers.
   return MOJO_RESULT_INVALID_ARGUMENT;
 }

 MojoResult Dispatcher::MapBufferImplNoLock(
     uint64_t /*offset*/,
     uint64_t /*num_bytes*/,
     MojoMapBufferFlags /*flags*/,
     scoped_ptr<PlatformSharedBufferMapping>* /*mapping*/) {
   lock_.AssertAcquired();
   DCHECK(!is_closed_);
   // By default, not supported. Only needed for buffer dispatchers.
   return MOJO_RESULT_INVALID_ARGUMENT;
 }

 HandleSignalsState Dispatcher::GetHandleSignalsStateImplNoLock() const {
   lock_.AssertAcquired();
   DCHECK(!is_closed_);
   // By default, waiting isn't supported. Only dispatchers that can be waited on
   // will do something nontrivial.
   return HandleSignalsState();
 }

 MojoResult Dispatcher::AddAwakableImplNoLock(
     Awakable* /*awakable*/,
     MojoHandleSignals /*signals*/,
     uintptr_t /*context*/,
     HandleSignalsState* signals_state) {
   lock_.AssertAcquired();
   DCHECK(!is_closed_);
   // By default, waiting isn't supported. Only dispatchers that can be waited on
   // will do something nontrivial.
   if (signals_state)
     *signals_state = HandleSignalsState();
   return MOJO_RESULT_FAILED_PRECONDITION;
 }

 void Dispatcher::RemoveAwakableImplNoLock(Awakable* /*awakable*/,
                                           HandleSignalsState* signals_state) {
   lock_.AssertAcquired();
   DCHECK(!is_closed_);
   // By default, waiting isn't supported. Only dispatchers that can be waited on
   // will do something nontrivial.
   if (signals_state)
     *signals_state = HandleSignalsState();
 }

 void Dispatcher::StartSerializeImplNoLock(size_t* max_size,
                                           size_t* max_platform_handles) {
   DCHECK(!is_closed_);
   *max_size = 0;
   *max_platform_handles = 0;
 }

 bool Dispatcher::EndSerializeAndCloseImplNoLock(
     void* /*destination*/,
     size_t* /*actual_size*/,
     PlatformHandleVector* /*platform_handles*/) {
   DCHECK(is_closed_);
   // By default, serializing isn't supported, so just close.
   CloseImplNoLock();
   return false;
 }

 bool Dispatcher::IsBusyNoLock() const {
   lock_.AssertAcquired();
   DCHECK(!is_closed_);
   // Most dispatchers support only "atomic" operations, so they are never busy
   // (in this sense).
   return false;
 }

 void Dispatcher::CloseNoLock() {
   lock_.AssertAcquired();
   DCHECK(!is_closed_);

   is_closed_ = true;
   CancelAllAwakablesNoLock();
   CloseImplNoLock();
 }

 scoped_refptr<Dispatcher>
 Dispatcher::CreateEquivalentDispatcherAndCloseNoLock() {
   lock_.AssertAcquired();
   DCHECK(!is_closed_);

   is_closed_ = true;
   CancelAllAwakablesNoLock();
   return CreateEquivalentDispatcherAndCloseImplNoLock();
 }

 void Dispatcher::StartSerialize(size_t* max_size,
                                 size_t* max_platform_handles) {
   DCHECK(max_size);
   DCHECK(max_platform_handles);
   DCHECK(!is_closed_);
   base::AutoLock locker(lock_);
   StartSerializeImplNoLock(max_size, max_platform_handles);
 }

 bool Dispatcher::EndSerializeAndClose(void* destination,
                                       size_t* actual_size,
                                       PlatformHandleVector* platform_handles) {
   DCHECK(actual_size);
   DCHECK(!is_closed_);

   // Like other |...Close()| methods, we mark ourselves as closed before calling
   // the impl. But there's no need to cancel waiters: we shouldn't have any (and
   // shouldn't be in |Core|'s handle table.
   is_closed_ = true;

   base::AutoLock locker(lock_);
   return EndSerializeAndCloseImplNoLock(destination, actual_size,
                                         platform_handles);
 }

 // DispatcherTransport ---------------------------------------------------------

 void DispatcherTransport::End() {
   DCHECK(dispatcher_);
   dispatcher_->lock_.Release();

   dispatcher_->TransportEnded();

   dispatcher_ = nullptr;
 }

 }  // namespace edk
 }  // namespace mojo
	// 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 "mojo/edk/system/dispatcher.h"

	#include "base/logging.h"
	#include "mojo/edk/system/configuration.h"
	#include "mojo/edk/system/data_pipe_consumer_dispatcher.h"
	#include "mojo/edk/system/data_pipe_producer_dispatcher.h"
	#include "mojo/edk/system/message_pipe_dispatcher.h"
	#include "mojo/edk/system/platform_handle_dispatcher.h"
	#include "mojo/edk/system/shared_buffer_dispatcher.h"

	namespace mojo {
	namespace edk {

	namespace test {

	// TODO(vtl): Maybe this should be defined in a test-only file instead.
	DispatcherTransport DispatcherTryStartTransport(Dispatcher* dispatcher) {
	return Dispatcher::HandleTableAccess::TryStartTransport(dispatcher);
	}

	} // namespace test

	// Dispatcher ------------------------------------------------------------------

	// static
	DispatcherTransport Dispatcher::HandleTableAccess::TryStartTransport(
	Dispatcher* dispatcher) {
	DCHECK(dispatcher);

	// Our dispatcher implementations hop to IO thread on initialization, so it's
	// valid that while their RawChannel os being initialized on IO thread, the
	// dispatcher is being sent. We handle this by just acquiring the lock.

	// See comment in header for why we need this.
	dispatcher->TransportStarted();

	dispatcher->lock_.Acquire();

	// We shouldn't race with things that close dispatchers, since closing can
	// only take place either under \|handle_table_lock_\| or when the handle is
	// marked as busy.
	DCHECK(!dispatcher->is_closed_);

	return DispatcherTransport(dispatcher);
	}

	// static
	void Dispatcher::TransportDataAccess::StartSerialize(
	Dispatcher* dispatcher,
	size_t* max_size,
	size_t* max_platform_handles) {
	DCHECK(dispatcher);
	dispatcher->StartSerialize(max_size, max_platform_handles);
	}

	// static
	bool Dispatcher::TransportDataAccess::EndSerializeAndClose(
	Dispatcher* dispatcher,
	void* destination,
	size_t* actual_size,
	PlatformHandleVector* platform_handles) {
	DCHECK(dispatcher);
	return dispatcher->EndSerializeAndClose(destination, actual_size,
	platform_handles);
	}

	// static
	scoped_refptr<Dispatcher> Dispatcher::TransportDataAccess::Deserialize(
	int32_t type,
	const void* source,
	size_t size,
	PlatformHandleVector* platform_handles) {
	switch (static_cast<Dispatcher::Type>(type)) {
	case Type::UNKNOWN:
	DVLOG(2) << "Deserializing invalid handle";
	return nullptr;
	case Type::MESSAGE_PIPE:
	return scoped_refptr<Dispatcher>(MessagePipeDispatcher::Deserialize(
	source, size, platform_handles));
	case Type::DATA_PIPE_PRODUCER:
	return scoped_refptr<Dispatcher>(
	DataPipeProducerDispatcher::Deserialize(
	source, size, platform_handles));
	case Type::DATA_PIPE_CONSUMER:
	return scoped_refptr<Dispatcher>(
	DataPipeConsumerDispatcher::Deserialize(
	source, size, platform_handles));
	case Type::SHARED_BUFFER:
	return scoped_refptr<Dispatcher>(SharedBufferDispatcher::Deserialize(
	source, size, platform_handles));
	case Type::PLATFORM_HANDLE:
	return scoped_refptr<Dispatcher>(PlatformHandleDispatcher::Deserialize(
	source, size, platform_handles));
	}
	LOG(WARNING) << "Unknown dispatcher type " << type;
	return nullptr;
	}

	MojoResult Dispatcher::Close() {
	base::AutoLock locker(lock_);
	if (is_closed_)
	return MOJO_RESULT_INVALID_ARGUMENT;

	CloseNoLock();
	return MOJO_RESULT_OK;
	}

	MojoResult Dispatcher::WriteMessage(
	const void* bytes,
	uint32_t num_bytes,
	std::vector<DispatcherTransport>* transports,
	MojoWriteMessageFlags flags) {
	DCHECK(!transports \|\|
	(transports->size() > 0 &&
	transports->size() < GetConfiguration().max_message_num_handles));

	base::AutoLock locker(lock_);
	if (is_closed_)
	return MOJO_RESULT_INVALID_ARGUMENT;

	return WriteMessageImplNoLock(bytes, num_bytes, transports, flags);
	}

	MojoResult Dispatcher::ReadMessage(void* bytes,
	uint32_t* num_bytes,
	DispatcherVector* dispatchers,
	uint32_t* num_dispatchers,
	MojoReadMessageFlags flags) {
	DCHECK(!num_dispatchers \|\| *num_dispatchers == 0 \|\|
	(dispatchers && dispatchers->empty()));

	base::AutoLock locker(lock_);
	if (is_closed_)
	return MOJO_RESULT_INVALID_ARGUMENT;

	return ReadMessageImplNoLock(bytes, num_bytes, dispatchers, num_dispatchers,
	flags);
	}

	MojoResult Dispatcher::WriteData(const void* elements,
	uint32_t* num_bytes,
	MojoWriteDataFlags flags) {
	base::AutoLock locker(lock_);
	if (is_closed_)
	return MOJO_RESULT_INVALID_ARGUMENT;

	return WriteDataImplNoLock(elements, num_bytes, flags);
	}

	MojoResult Dispatcher::BeginWriteData(void** buffer,
	uint32_t* buffer_num_bytes,
	MojoWriteDataFlags flags) {
	base::AutoLock locker(lock_);
	if (is_closed_)
	return MOJO_RESULT_INVALID_ARGUMENT;

	return BeginWriteDataImplNoLock(buffer, buffer_num_bytes, flags);
	}

	MojoResult Dispatcher::EndWriteData(uint32_t num_bytes_written) {
	base::AutoLock locker(lock_);
	if (is_closed_)
	return MOJO_RESULT_INVALID_ARGUMENT;

	return EndWriteDataImplNoLock(num_bytes_written);
	}

	MojoResult Dispatcher::ReadData(void* elements,
	uint32_t* num_bytes,
	MojoReadDataFlags flags) {
	base::AutoLock locker(lock_);
	if (is_closed_)
	return MOJO_RESULT_INVALID_ARGUMENT;

	return ReadDataImplNoLock(elements, num_bytes, flags);
	}

	MojoResult Dispatcher::BeginReadData(const void** buffer,
	uint32_t* buffer_num_bytes,
	MojoReadDataFlags flags) {
	base::AutoLock locker(lock_);
	if (is_closed_)
	return MOJO_RESULT_INVALID_ARGUMENT;

	return BeginReadDataImplNoLock(buffer, buffer_num_bytes, flags);
	}

	MojoResult Dispatcher::EndReadData(uint32_t num_bytes_read) {
	base::AutoLock locker(lock_);
	if (is_closed_)
	return MOJO_RESULT_INVALID_ARGUMENT;

	return EndReadDataImplNoLock(num_bytes_read);
	}

	MojoResult Dispatcher::DuplicateBufferHandle(
	const MojoDuplicateBufferHandleOptions* options,
	scoped_refptr<Dispatcher>* new_dispatcher) {
	base::AutoLock locker(lock_);
	if (is_closed_)
	return MOJO_RESULT_INVALID_ARGUMENT;

	return DuplicateBufferHandleImplNoLock(options, new_dispatcher);
	}

	MojoResult Dispatcher::MapBuffer(
	uint64_t offset,
	uint64_t num_bytes,
	MojoMapBufferFlags flags,
	scoped_ptr<PlatformSharedBufferMapping>* mapping) {
	base::AutoLock locker(lock_);
	if (is_closed_)
	return MOJO_RESULT_INVALID_ARGUMENT;

	return MapBufferImplNoLock(offset, num_bytes, flags, mapping);
	}

	HandleSignalsState Dispatcher::GetHandleSignalsState() const {
	base::AutoLock locker(lock_);
	if (is_closed_)
	return HandleSignalsState();

	return GetHandleSignalsStateImplNoLock();
	}

	MojoResult Dispatcher::AddAwakable(Awakable* awakable,
	MojoHandleSignals signals,
	uintptr_t context,
	HandleSignalsState* signals_state) {
	base::AutoLock locker(lock_);
	if (is_closed_) {
	if (signals_state)
	*signals_state = HandleSignalsState();
	return MOJO_RESULT_INVALID_ARGUMENT;
	}

	return AddAwakableImplNoLock(awakable, signals, context, signals_state);
	}

	void Dispatcher::RemoveAwakable(Awakable* awakable,
	HandleSignalsState* handle_signals_state) {
	base::AutoLock locker(lock_);
	if (is_closed_) {
	if (handle_signals_state)
	*handle_signals_state = HandleSignalsState();
	return;
	}

	RemoveAwakableImplNoLock(awakable, handle_signals_state);
	}

	Dispatcher::Dispatcher() : is_closed_(false) {
	}

	Dispatcher::~Dispatcher() {
	// Make sure that \|Close()\| was called.
	DCHECK(is_closed_);
	}

	void Dispatcher::CancelAllAwakablesNoLock() {
	lock_.AssertAcquired();
	DCHECK(is_closed_);
	// By default, waiting isn't supported. Only dispatchers that can be waited on
	// will do something nontrivial.
	}

	void Dispatcher::CloseImplNoLock() {
	lock_.AssertAcquired();
	DCHECK(is_closed_);
	// This may not need to do anything. Dispatchers should override this to do
	// any actual close-time cleanup necessary.
	}

	MojoResult Dispatcher::WriteMessageImplNoLock(
	const void* /bytes/,
	uint32_t /num_bytes/,
	std::vector<DispatcherTransport>* /transports/,
	MojoWriteMessageFlags /flags/) {
	lock_.AssertAcquired();
	DCHECK(!is_closed_);
	// By default, not supported. Only needed for message pipe dispatchers.
	return MOJO_RESULT_INVALID_ARGUMENT;
	}

	MojoResult Dispatcher::ReadMessageImplNoLock(
	void* /bytes/,
	uint32_t* /num_bytes/,
	DispatcherVector* /dispatchers/,
	uint32_t* /num_dispatchers/,
	MojoReadMessageFlags /flags/) {
	lock_.AssertAcquired();
	DCHECK(!is_closed_);
	// By default, not supported. Only needed for message pipe dispatchers.
	return MOJO_RESULT_INVALID_ARGUMENT;
	}

	MojoResult Dispatcher::WriteDataImplNoLock(const void* /elements/,
	uint32_t* /num_bytes/,
	MojoWriteDataFlags /flags/) {
	lock_.AssertAcquired();
	DCHECK(!is_closed_);
	// By default, not supported. Only needed for data pipe dispatchers.
	return MOJO_RESULT_INVALID_ARGUMENT;
	}

	MojoResult Dispatcher::BeginWriteDataImplNoLock(
	void** /buffer/,
	uint32_t* /buffer_num_bytes/,
	MojoWriteDataFlags /flags/) {
	lock_.AssertAcquired();
	DCHECK(!is_closed_);
	// By default, not supported. Only needed for data pipe dispatchers.
	return MOJO_RESULT_INVALID_ARGUMENT;
	}

	MojoResult Dispatcher::EndWriteDataImplNoLock(uint32_t /num_bytes_written/) {
	lock_.AssertAcquired();
	DCHECK(!is_closed_);
	// By default, not supported. Only needed for data pipe dispatchers.
	return MOJO_RESULT_INVALID_ARGUMENT;
	}

	MojoResult Dispatcher::ReadDataImplNoLock(void* /elements/,
	uint32_t* /num_bytes/,
	MojoReadDataFlags /flags/) {
	lock_.AssertAcquired();
	DCHECK(!is_closed_);
	// By default, not supported. Only needed for data pipe dispatchers.
	return MOJO_RESULT_INVALID_ARGUMENT;
	}

	MojoResult Dispatcher::BeginReadDataImplNoLock(
	const void** /buffer/,
	uint32_t* /buffer_num_bytes/,
	MojoReadDataFlags /flags/) {
	lock_.AssertAcquired();
	DCHECK(!is_closed_);
	// By default, not supported. Only needed for data pipe dispatchers.
	return MOJO_RESULT_INVALID_ARGUMENT;
	}

	MojoResult Dispatcher::EndReadDataImplNoLock(uint32_t /num_bytes_read/) {
	lock_.AssertAcquired();
	DCHECK(!is_closed_);
	// By default, not supported. Only needed for data pipe dispatchers.
	return MOJO_RESULT_INVALID_ARGUMENT;
	}

	MojoResult Dispatcher::DuplicateBufferHandleImplNoLock(
	const MojoDuplicateBufferHandleOptions* /options/,
	scoped_refptr<Dispatcher>* /new_dispatcher/) {
	lock_.AssertAcquired();
	DCHECK(!is_closed_);
	// By default, not supported. Only needed for buffer dispatchers.
	return MOJO_RESULT_INVALID_ARGUMENT;
	}

	MojoResult Dispatcher::MapBufferImplNoLock(
	uint64_t /offset/,
	uint64_t /num_bytes/,
	MojoMapBufferFlags /flags/,
	scoped_ptr<PlatformSharedBufferMapping>* /mapping/) {
	lock_.AssertAcquired();
	DCHECK(!is_closed_);
	// By default, not supported. Only needed for buffer dispatchers.
	return MOJO_RESULT_INVALID_ARGUMENT;
	}

	HandleSignalsState Dispatcher::GetHandleSignalsStateImplNoLock() const {
	lock_.AssertAcquired();
	DCHECK(!is_closed_);
	// By default, waiting isn't supported. Only dispatchers that can be waited on
	// will do something nontrivial.
	return HandleSignalsState();
	}

	MojoResult Dispatcher::AddAwakableImplNoLock(
	Awakable* /awakable/,
	MojoHandleSignals /signals/,
	uintptr_t /context/,
	HandleSignalsState* signals_state) {
	lock_.AssertAcquired();
	DCHECK(!is_closed_);
	// By default, waiting isn't supported. Only dispatchers that can be waited on
	// will do something nontrivial.
	if (signals_state)
	*signals_state = HandleSignalsState();
	return MOJO_RESULT_FAILED_PRECONDITION;
	}

	void Dispatcher::RemoveAwakableImplNoLock(Awakable* /awakable/,
	HandleSignalsState* signals_state) {
	lock_.AssertAcquired();
	DCHECK(!is_closed_);
	// By default, waiting isn't supported. Only dispatchers that can be waited on
	// will do something nontrivial.
	if (signals_state)
	*signals_state = HandleSignalsState();
	}

	void Dispatcher::StartSerializeImplNoLock(size_t* max_size,
	size_t* max_platform_handles) {
	DCHECK(!is_closed_);
	*max_size = 0;
	*max_platform_handles = 0;
	}

	bool Dispatcher::EndSerializeAndCloseImplNoLock(
	void* /destination/,
	size_t* /actual_size/,
	PlatformHandleVector* /platform_handles/) {
	DCHECK(is_closed_);
	// By default, serializing isn't supported, so just close.
	CloseImplNoLock();
	return false;
	}

	bool Dispatcher::IsBusyNoLock() const {
	lock_.AssertAcquired();
	DCHECK(!is_closed_);
	// Most dispatchers support only "atomic" operations, so they are never busy
	// (in this sense).
	return false;
	}

	void Dispatcher::CloseNoLock() {
	lock_.AssertAcquired();
	DCHECK(!is_closed_);

	is_closed_ = true;
	CancelAllAwakablesNoLock();
	CloseImplNoLock();
	}

	scoped_refptr<Dispatcher>
	Dispatcher::CreateEquivalentDispatcherAndCloseNoLock() {
	lock_.AssertAcquired();
	DCHECK(!is_closed_);

	is_closed_ = true;
	CancelAllAwakablesNoLock();
	return CreateEquivalentDispatcherAndCloseImplNoLock();
	}

	void Dispatcher::StartSerialize(size_t* max_size,
	size_t* max_platform_handles) {
	DCHECK(max_size);
	DCHECK(max_platform_handles);
	DCHECK(!is_closed_);
	base::AutoLock locker(lock_);
	StartSerializeImplNoLock(max_size, max_platform_handles);
	}

	bool Dispatcher::EndSerializeAndClose(void* destination,
	size_t* actual_size,
	PlatformHandleVector* platform_handles) {
	DCHECK(actual_size);
	DCHECK(!is_closed_);

	// Like other \|...Close()\| methods, we mark ourselves as closed before calling
	// the impl. But there's no need to cancel waiters: we shouldn't have any (and
	// shouldn't be in \|Core\|'s handle table.
	is_closed_ = true;

	base::AutoLock locker(lock_);
	return EndSerializeAndCloseImplNoLock(destination, actual_size,
	platform_handles);
	}

	// DispatcherTransport ---------------------------------------------------------

	void DispatcherTransport::End() {
	DCHECK(dispatcher_);
	dispatcher_->lock_.Release();

	dispatcher_->TransportEnded();

	dispatcher_ = nullptr;
	}

	} // namespace edk
	} // namespace mojo