Straightens outs DEPS in mojo/common

mojo/common/handle_watcher.cc

Index: mojo/common/handle_watcher.cc
diff --git a/mojo/common/handle_watcher.cc b/mojo/common/handle_watcher.cc
deleted file mode 100644
index 6bff0cd1a8981bfdcb190981d6d4b7aa93b88915..0000000000000000000000000000000000000000
--- a/mojo/common/handle_watcher.cc
+++ /dev/null
@@ -1,475 +0,0 @@
-// 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/common/handle_watcher.h"
-
-#include <map>
-
-#include "base/atomic_sequence_num.h"
-#include "base/bind.h"
-#include "base/lazy_instance.h"
-#include "base/logging.h"
-#include "base/macros.h"
-#include "base/memory/singleton.h"
-#include "base/memory/weak_ptr.h"
-#include "base/message_loop/message_loop.h"
-#include "base/single_thread_task_runner.h"
-#include "base/synchronization/lock.h"
-#include "base/synchronization/waitable_event.h"
-#include "base/thread_task_runner_handle.h"
-#include "base/threading/thread.h"
-#include "base/threading/thread_restrictions.h"
-#include "base/time/time.h"
-#include "mojo/common/message_pump_mojo.h"
-#include "mojo/common/message_pump_mojo_handler.h"
-#include "mojo/common/time_helper.h"
-
-namespace mojo {
-namespace common {
-
-typedef int WatcherID;
-
-namespace {
-
-const char kWatcherThreadName[] = "handle-watcher-thread";
-
-base::TimeTicks MojoDeadlineToTimeTicks(MojoDeadline deadline) {
-  return deadline == MOJO_DEADLINE_INDEFINITE ? base::TimeTicks() :
-      internal::NowTicks() + base::TimeDelta::FromMicroseconds(deadline);
-}
-
-// Tracks the data for a single call to Start().
-struct WatchData {
-  WatchData()
-      : id(0), handle_signals(MOJO_HANDLE_SIGNAL_NONE), task_runner(NULL) {}
-
-  WatcherID id;
-  Handle handle;
-  MojoHandleSignals handle_signals;
-  base::TimeTicks deadline;
-  base::Callback<void(MojoResult)> callback;
-  scoped_refptr<base::SingleThreadTaskRunner> task_runner;
-};
-
-// WatcherBackend --------------------------------------------------------------
-
-// WatcherBackend is responsible for managing the requests and interacting with
-// MessagePumpMojo. All access (outside of creation/destruction) is done on the
-// thread WatcherThreadManager creates.
-class WatcherBackend : public MessagePumpMojoHandler {
- public:
-  WatcherBackend();
-  ~WatcherBackend() override;
-
-  void StartWatching(const WatchData& data);
-
-  // Cancels a previously scheduled request to start a watch.
-  void StopWatching(WatcherID watcher_id);
-
- private:
-  typedef std::map<Handle, WatchData> HandleToWatchDataMap;
-
-  // Invoked when a handle needs to be removed and notified.
-  void RemoveAndNotify(const Handle& handle, MojoResult result);
-
-  // Searches through |handle_to_data_| for |watcher_id|. Returns true if found
-  // and sets |handle| to the Handle. Returns false if not a known id.
-  bool GetMojoHandleByWatcherID(WatcherID watcher_id, Handle* handle) const;
-
-  // MessagePumpMojoHandler overrides:
-  void OnHandleReady(const Handle& handle) override;
-  void OnHandleError(const Handle& handle, MojoResult result) override;
-
-  // Maps from assigned id to WatchData.
-  HandleToWatchDataMap handle_to_data_;
-
-  DISALLOW_COPY_AND_ASSIGN(WatcherBackend);
-};
-
-WatcherBackend::WatcherBackend() {
-}
-
-WatcherBackend::~WatcherBackend() {
-}
-
-void WatcherBackend::StartWatching(const WatchData& data) {
-  RemoveAndNotify(data.handle, MOJO_RESULT_CANCELLED);
-
-  DCHECK_EQ(0u, handle_to_data_.count(data.handle));
-
-  handle_to_data_[data.handle] = data;
-  MessagePumpMojo::current()->AddHandler(this, data.handle,
-                                         data.handle_signals,
-                                         data.deadline);
-}
-
-void WatcherBackend::StopWatching(WatcherID watcher_id) {
-  // Because of the thread hop it is entirely possible to get here and not
-  // have a valid handle registered for |watcher_id|.
-  Handle handle;
-  if (GetMojoHandleByWatcherID(watcher_id, &handle)) {
-    handle_to_data_.erase(handle);
-    MessagePumpMojo::current()->RemoveHandler(handle);
-  }
-}
-
-void WatcherBackend::RemoveAndNotify(const Handle& handle,
-                                     MojoResult result) {
-  if (handle_to_data_.count(handle) == 0)
-    return;
-
-  const WatchData data(handle_to_data_[handle]);
-  handle_to_data_.erase(handle);
-  MessagePumpMojo::current()->RemoveHandler(handle);
-
-  data.task_runner->PostTask(FROM_HERE, base::Bind(data.callback, result));
-}
-
-bool WatcherBackend::GetMojoHandleByWatcherID(WatcherID watcher_id,
-                                              Handle* handle) const {
-  for (HandleToWatchDataMap::const_iterator i = handle_to_data_.begin();
-       i != handle_to_data_.end(); ++i) {
-    if (i->second.id == watcher_id) {
-      *handle = i->second.handle;
-      return true;
-    }
-  }
-  return false;
-}
-
-void WatcherBackend::OnHandleReady(const Handle& handle) {
-  RemoveAndNotify(handle, MOJO_RESULT_OK);
-}
-
-void WatcherBackend::OnHandleError(const Handle& handle, MojoResult result) {
-  RemoveAndNotify(handle, result);
-}
-
-// WatcherThreadManager --------------------------------------------------------
-
-// WatcherThreadManager manages the background thread that listens for handles
-// to be ready. All requests are handled by WatcherBackend.
-}  // namespace
-
-class WatcherThreadManager {
- public:
-  ~WatcherThreadManager();
-
-  // Returns the shared instance.
-  static WatcherThreadManager* GetInstance();
-
-  // Starts watching the requested handle. Returns a unique ID that is used to
-  // stop watching the handle. When the handle is ready |callback| is notified
-  // on the thread StartWatching() was invoked on.
-  // This may be invoked on any thread.
-  WatcherID StartWatching(const Handle& handle,
-                          MojoHandleSignals handle_signals,
-                          base::TimeTicks deadline,
-                          const base::Callback<void(MojoResult)>& callback);
-
-  // Stops watching a handle.
-  // This may be invoked on any thread.
-  void StopWatching(WatcherID watcher_id);
-
- private:
-  enum RequestType {
-    REQUEST_START,
-    REQUEST_STOP,
-  };
-
-  // See description of |requests_| for details.
-  struct RequestData {
-    RequestData() : type(REQUEST_START), stop_id(0), stop_event(NULL) {}
-
-    RequestType type;
-    WatchData start_data;
-    WatcherID stop_id;
-    base::WaitableEvent* stop_event;
-  };
-
-  typedef std::vector<RequestData> Requests;
-
-  friend struct DefaultSingletonTraits<WatcherThreadManager>;
-
-  WatcherThreadManager();
-
-  // Schedules a request on the background thread. See |requests_| for details.
-  void AddRequest(const RequestData& data);
-
-  // Processes requests added to |requests_|. This is invoked on the backend
-  // thread.
-  void ProcessRequestsOnBackendThread();
-
-  base::Thread thread_;
-
-  base::AtomicSequenceNumber watcher_id_generator_;
-
-  WatcherBackend backend_;
-
-  // Protects |requests_|.
-  base::Lock lock_;
-
-  // Start/Stop result in adding a RequestData to |requests_| (protected by
-  // |lock_|). When the background thread wakes up it processes the requests.
-  Requests requests_;
-
-  DISALLOW_COPY_AND_ASSIGN(WatcherThreadManager);
-};
-
-WatcherThreadManager::~WatcherThreadManager() {
-  thread_.Stop();
-}
-
-WatcherThreadManager* WatcherThreadManager::GetInstance() {
-  return Singleton<WatcherThreadManager>::get();
-}
-
-WatcherID WatcherThreadManager::StartWatching(
-    const Handle& handle,
-    MojoHandleSignals handle_signals,
-    base::TimeTicks deadline,
-    const base::Callback<void(MojoResult)>& callback) {
-  RequestData request_data;
-  request_data.type = REQUEST_START;
-  request_data.start_data.id = watcher_id_generator_.GetNext();
-  request_data.start_data.handle = handle;
-  request_data.start_data.callback = callback;
-  request_data.start_data.handle_signals = handle_signals;
-  request_data.start_data.deadline = deadline;
-  request_data.start_data.task_runner = base::ThreadTaskRunnerHandle::Get();
-  AddRequest(request_data);
-  return request_data.start_data.id;
-}
-
-void WatcherThreadManager::StopWatching(WatcherID watcher_id) {
-  // Handle the case of StartWatching() followed by StopWatching() before
-  // |thread_| woke up.
-  {
-    base::AutoLock auto_lock(lock_);
-    for (Requests::iterator i = requests_.begin(); i != requests_.end(); ++i) {
-      if (i->type == REQUEST_START && i->start_data.id == watcher_id) {
-        // Watcher ids are not reused, so if we find it we can stop.
-        requests_.erase(i);
-        return;
-      }
-    }
-  }
-
-  base::ThreadRestrictions::ScopedAllowWait allow_wait;
-  base::WaitableEvent event(true, false);
-  RequestData request_data;
-  request_data.type = REQUEST_STOP;
-  request_data.stop_id = watcher_id;
-  request_data.stop_event = &event;
-  AddRequest(request_data);
-
-  // We need to block until the handle is actually removed.
-  event.Wait();
-}
-
-void WatcherThreadManager::AddRequest(const RequestData& data) {
-  {
-    base::AutoLock auto_lock(lock_);
-    const bool was_empty = requests_.empty();
-    requests_.push_back(data);
-    if (!was_empty)
-      return;
-  }
-  // We own |thread_|, so it's safe to use Unretained() here.
-  thread_.task_runner()->PostTask(
-      FROM_HERE,
-      base::Bind(&WatcherThreadManager::ProcessRequestsOnBackendThread,
-                 base::Unretained(this)));
-}
-
-void WatcherThreadManager::ProcessRequestsOnBackendThread() {
-  DCHECK_EQ(thread_.message_loop(), base::MessageLoop::current());
-
-  Requests requests;
-  {
-    base::AutoLock auto_lock(lock_);
-    requests_.swap(requests);
-  }
-  for (size_t i = 0; i < requests.size(); ++i) {
-    if (requests[i].type == REQUEST_START) {
-      backend_.StartWatching(requests[i].start_data);
-    } else {
-      backend_.StopWatching(requests[i].stop_id);
-      requests[i].stop_event->Signal();
-    }
-  }
-}
-
-WatcherThreadManager::WatcherThreadManager()
-    : thread_(kWatcherThreadName) {
-  base::Thread::Options thread_options;
-  thread_options.message_pump_factory = base::Bind(&MessagePumpMojo::Create);
-  thread_.StartWithOptions(thread_options);
-}
-
-// HandleWatcher::StateBase and subclasses -------------------------------------
-
-// The base class of HandleWatcher's state. Owns the user's callback and
-// monitors the current thread's MessageLoop to know when to force the callback
-// to run (with an error) even though the pipe hasn't been signaled yet.
-class HandleWatcher::StateBase : public base::MessageLoop::DestructionObserver {
- public:
-  StateBase(HandleWatcher* watcher,
-            const base::Callback<void(MojoResult)>& callback)
-      : watcher_(watcher),
-        callback_(callback),
-        got_ready_(false) {
-    base::MessageLoop::current()->AddDestructionObserver(this);
-  }
-
-  ~StateBase() override {
-    base::MessageLoop::current()->RemoveDestructionObserver(this);
-  }
-
- protected:
-  void NotifyHandleReady(MojoResult result) {
-    got_ready_ = true;
-    NotifyAndDestroy(result);
-  }
-
-  bool got_ready() const { return got_ready_; }
-
- private:
-  void WillDestroyCurrentMessageLoop() override {
-    // The current thread is exiting. Simulate a watch error.
-    NotifyAndDestroy(MOJO_RESULT_ABORTED);
-  }
-
-  void NotifyAndDestroy(MojoResult result) {
-    base::Callback<void(MojoResult)> callback = callback_;
-    watcher_->Stop();  // Destroys |this|.
-
-    callback.Run(result);
-  }
-
-  HandleWatcher* watcher_;
-  base::Callback<void(MojoResult)> callback_;
-
-  // Have we been notified that the handle is ready?
-  bool got_ready_;
-
-  DISALLOW_COPY_AND_ASSIGN(StateBase);
-};
-
-// If the thread on which HandleWatcher is used runs MessagePumpMojo,
-// SameThreadWatchingState is used to directly watch the handle on the same
-// thread.
-class HandleWatcher::SameThreadWatchingState : public StateBase,
-                                               public MessagePumpMojoHandler {
- public:
-  SameThreadWatchingState(HandleWatcher* watcher,
-                          const Handle& handle,
-                          MojoHandleSignals handle_signals,
-                          MojoDeadline deadline,
-                          const base::Callback<void(MojoResult)>& callback)
-      : StateBase(watcher, callback),
-        handle_(handle) {
-    DCHECK(MessagePumpMojo::IsCurrent());
-
-    MessagePumpMojo::current()->AddHandler(
-        this, handle, handle_signals, MojoDeadlineToTimeTicks(deadline));
-  }
-
-  ~SameThreadWatchingState() override {
-    if (!got_ready())
-      MessagePumpMojo::current()->RemoveHandler(handle_);
-  }
-
- private:
-  // MessagePumpMojoHandler overrides:
-  void OnHandleReady(const Handle& handle) override {
-    StopWatchingAndNotifyReady(handle, MOJO_RESULT_OK);
-  }
-
-  void OnHandleError(const Handle& handle, MojoResult result) override {
-    StopWatchingAndNotifyReady(handle, result);
-  }
-
-  void StopWatchingAndNotifyReady(const Handle& handle, MojoResult result) {
-    DCHECK_EQ(handle.value(), handle_.value());
-    MessagePumpMojo::current()->RemoveHandler(handle_);
-    NotifyHandleReady(result);
-  }
-
-  Handle handle_;
-
-  DISALLOW_COPY_AND_ASSIGN(SameThreadWatchingState);
-};
-
-// If the thread on which HandleWatcher is used runs a message pump different
-// from MessagePumpMojo, SecondaryThreadWatchingState is used to watch the
-// handle on the handle watcher thread.
-class HandleWatcher::SecondaryThreadWatchingState : public StateBase {
- public:
-  SecondaryThreadWatchingState(HandleWatcher* watcher,
-                               const Handle& handle,
-                               MojoHandleSignals handle_signals,
-                               MojoDeadline deadline,
-                               const base::Callback<void(MojoResult)>& callback)
-      : StateBase(watcher, callback),
-        weak_factory_(this) {
-    watcher_id_ = WatcherThreadManager::GetInstance()->StartWatching(
-        handle,
-        handle_signals,
-        MojoDeadlineToTimeTicks(deadline),
-        base::Bind(&SecondaryThreadWatchingState::NotifyHandleReady,
-                   weak_factory_.GetWeakPtr()));
-  }
-
-  ~SecondaryThreadWatchingState() override {
-    // If we've been notified the handle is ready (|got_ready()| is true) then
-    // the watch has been implicitly removed by
-    // WatcherThreadManager/MessagePumpMojo and we don't have to call
-    // StopWatching(). To do so would needlessly entail posting a task and
-    // blocking until the background thread services it.
-    if (!got_ready())
-      WatcherThreadManager::GetInstance()->StopWatching(watcher_id_);
-  }
-
- private:
-  WatcherID watcher_id_;
-
-  // Used to weakly bind |this| to the WatcherThreadManager.
-  base::WeakPtrFactory<SecondaryThreadWatchingState> weak_factory_;
-
-  DISALLOW_COPY_AND_ASSIGN(SecondaryThreadWatchingState);
-};
-
-// HandleWatcher ---------------------------------------------------------------
-
-HandleWatcher::HandleWatcher() {
-}
-
-HandleWatcher::~HandleWatcher() {
-}
-
-void HandleWatcher::Start(const Handle& handle,
-                          MojoHandleSignals handle_signals,
-                          MojoDeadline deadline,
-                          const base::Callback<void(MojoResult)>& callback) {
-  DCHECK(handle.is_valid());
-  DCHECK_NE(MOJO_HANDLE_SIGNAL_NONE, handle_signals);
-
-  // Need to clear the state before creating a new one.
-  state_.reset();
-  if (MessagePumpMojo::IsCurrent()) {
-    state_.reset(new SameThreadWatchingState(
-        this, handle, handle_signals, deadline, callback));
-  } else {
-    state_.reset(new SecondaryThreadWatchingState(
-        this, handle, handle_signals, deadline, callback));
-  }
-}
-
-void HandleWatcher::Stop() {
-  state_.reset();
-}
-
-}  // namespace common
-}  // namespace mojo