remoting/base/plugin_message_loop_proxy.cc

// Copyright (c) 2011 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 "remoting/base/plugin_message_loop_proxy.h"

#include "base/bind.h"

namespace remoting {

PluginMessageLoopProxy::PluginMessageLoopProxy(Delegate* delegate)
    : plugin_thread_id_(base::PlatformThread::CurrentId()),
      delegate_(delegate) {
}

PluginMessageLoopProxy::~PluginMessageLoopProxy() {
}

void PluginMessageLoopProxy::Detach() {
  base::AutoLock auto_lock(lock_);
  if (delegate_) {
    DCHECK(BelongsToCurrentThread());
    delegate_ = NULL;
  }
}

// MessageLoopProxy interface implementation.
bool PluginMessageLoopProxy::PostTask(
    const tracked_objects::Location& from_here,
    Task* task) {
  return PostDelayedTask(from_here, task, 0);
}

bool PluginMessageLoopProxy::PostDelayedTask(
    const tracked_objects::Location& from_here,
    Task* task,
    int64 delay_ms) {
  base::AutoLock auto_lock(lock_);
  if (!delegate_)
    return false;

  base::Closure* springpad_closure = new base::Closure(base::Bind(
      &PluginMessageLoopProxy::RunTaskIf, this, task));
  return delegate_->RunOnPluginThread(
      delay_ms, &PluginMessageLoopProxy::TaskSpringboard, springpad_closure);
}

bool PluginMessageLoopProxy::PostNonNestableTask(
    const tracked_objects::Location& from_here,
    Task* task) {
  // All tasks running on this message loop are non-nestable.
  return PostTask(from_here, task);
}

bool PluginMessageLoopProxy::PostNonNestableDelayedTask(
      const tracked_objects::Location& from_here,
      Task* task,
      int64 delay_ms) {
  // All tasks running on this message loop are non-nestable.
  return PostDelayedTask(from_here, task, delay_ms);
}

bool PluginMessageLoopProxy::PostTask(
    const tracked_objects::Location& from_here,
    const base::Closure& task) {
  return PostDelayedTask(from_here, task, 0);
}

bool PluginMessageLoopProxy::PostDelayedTask(
    const tracked_objects::Location& from_here,
    const base::Closure& task,
    int64 delay_ms) {
  base::AutoLock auto_lock(lock_);
  if (!delegate_)
    return false;

  base::Closure* springpad_closure = new base::Closure(base::Bind(
      &PluginMessageLoopProxy::RunClosureIf, this, task));
  return delegate_->RunOnPluginThread(
      delay_ms, &PluginMessageLoopProxy::TaskSpringboard, springpad_closure);
}

bool PluginMessageLoopProxy::PostNonNestableTask(
    const tracked_objects::Location& from_here,
    const base::Closure& task) {
  // All tasks running on this message loop are non-nestable.
  return PostTask(from_here, task);
}

bool PluginMessageLoopProxy::PostNonNestableDelayedTask(
    const tracked_objects::Location& from_here,
    const base::Closure& task,
    int64 delay_ms) {
  // All tasks running on this message loop are non-nestable.
  return PostDelayedTask(from_here, task, delay_ms);
}

bool PluginMessageLoopProxy::BelongsToCurrentThread() {
  // In pepper plugins ideally we should use pp::Core::IsMainThread,
  // but it is problematic becase we would need to keep reference to
  // Core somewhere, e.g. make the delegate ref-counted.
  return base::PlatformThread::CurrentId() == plugin_thread_id_;
}

// static
void PluginMessageLoopProxy::TaskSpringboard(void* data) {
  base::Closure* task = reinterpret_cast<base::Closure*>(data);
  task->Run();
  delete task;
}

void PluginMessageLoopProxy::RunTaskIf(Task* task) {
  DCHECK(BelongsToCurrentThread());
  // |delegate_| can be changed only from our thread, so it's safe to
  // access it without acquiring |lock_|.
  if (delegate_)
    task->Run();
  delete task;
}

void PluginMessageLoopProxy::RunClosureIf(const base::Closure& task) {
  // |delegate_| can be changed only from our thread, so it's safe to
  // access it without acquiring |lock_|.
  if (delegate_)
    task.Run();
}

}  // namespace remoting