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// 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 <cmath>
#include <set>
#include <vector>
#include "base/bind.h"
#include "base/logging.h"
#include "base/message_loop.h"
#include "base/threading/thread.h"
#include "base/threading/thread_restrictions.h"
#include "content/browser/gamepad/data_fetcher.h"
#include "content/browser/gamepad/gamepad_provider.h"
#include "content/browser/gamepad/platform_data_fetcher.h"
#include "content/common/gamepad_messages.h"
#include "content/public/browser/browser_thread.h"
namespace content {
GamepadProvider::GamepadProvider(GamepadDataFetcher* fetcher)
: is_paused_(false),
devices_changed_(true),
provided_fetcher_(fetcher),
ALLOW_THIS_IN_INITIALIZER_LIST(weak_factory_(this)) {
size_t data_size = sizeof(GamepadHardwareBuffer);
base::SystemMonitor* monitor = base::SystemMonitor::Get();
if (monitor)
monitor->AddDevicesChangedObserver(this);
bool res = gamepad_shared_memory_.CreateAndMapAnonymous(data_size);
DCHECK(res);
GamepadHardwareBuffer* hwbuf = SharedMemoryAsHardwareBuffer();
memset(hwbuf, 0, sizeof(GamepadHardwareBuffer));
polling_thread_.reset(new base::Thread("Gamepad polling thread"));
polling_thread_->StartWithOptions(
base::Thread::Options(MessageLoop::TYPE_IO, 0));
MessageLoop* polling_loop = polling_thread_->message_loop();
polling_loop->PostTask(
FROM_HERE,
base::Bind(&GamepadProvider::DoInitializePollingThread, this));
}
GamepadProvider::~GamepadProvider() {
base::SystemMonitor* monitor = base::SystemMonitor::Get();
if (monitor)
monitor->RemoveDevicesChangedObserver(this);
polling_thread_.reset();
data_fetcher_.reset();
}
base::SharedMemoryHandle GamepadProvider::GetRendererSharedMemoryHandle(
base::ProcessHandle process) {
base::SharedMemoryHandle renderer_handle;
gamepad_shared_memory_.ShareToProcess(process, &renderer_handle);
return renderer_handle;
}
void GamepadProvider::Pause() {
{
base::AutoLock lock(is_paused_lock_);
is_paused_ = true;
}
if (data_fetcher_.get())
data_fetcher_->PauseHint(true);
}
void GamepadProvider::Resume() {
{
base::AutoLock lock(is_paused_lock_);
if (!is_paused_)
return;
is_paused_ = false;
}
if (data_fetcher_.get())
data_fetcher_->PauseHint(false);
MessageLoop* polling_loop = polling_thread_->message_loop();
polling_loop->PostTask(
FROM_HERE,
base::Bind(&GamepadProvider::ScheduleDoPoll, this));
}
void GamepadProvider::OnDevicesChanged() {
base::AutoLock lock(devices_changed_lock_);
devices_changed_ = true;
}
void GamepadProvider::DoInitializePollingThread() {
DCHECK(MessageLoop::current() == polling_thread_->message_loop());
if (!provided_fetcher_.get())
provided_fetcher_.reset(new GamepadPlatformDataFetcher);
// Pass ownership of fetcher to provider_.
data_fetcher_.swap(provided_fetcher_);
// Start polling.
ScheduleDoPoll();
}
void GamepadProvider::DoPoll() {
DCHECK(MessageLoop::current() == polling_thread_->message_loop());
bool changed;
GamepadHardwareBuffer* hwbuf = SharedMemoryAsHardwareBuffer();
ANNOTATE_BENIGN_RACE_SIZED(
&hwbuf->buffer,
sizeof(WebKit::WebGamepads),
"Racey reads are discarded");
{
base::AutoLock lock(devices_changed_lock_);
changed = devices_changed_;
devices_changed_ = false;
}
// Acquire the SeqLock. There is only ever one writer to this data.
// See gamepad_hardware_buffer.h.
hwbuf->sequence.WriteBegin();
data_fetcher_->GetGamepadData(&hwbuf->buffer, changed);
hwbuf->sequence.WriteEnd();
// Schedule our next interval of polling.
ScheduleDoPoll();
}
void GamepadProvider::ScheduleDoPoll() {
DCHECK(MessageLoop::current() == polling_thread_->message_loop());
{
base::AutoLock lock(is_paused_lock_);
if (is_paused_)
return;
}
MessageLoop::current()->PostDelayedTask(
FROM_HERE,
base::Bind(&GamepadProvider::DoPoll, weak_factory_.GetWeakPtr()),
kDesiredSamplingIntervalMs);
}
GamepadHardwareBuffer* GamepadProvider::SharedMemoryAsHardwareBuffer() {
void* mem = gamepad_shared_memory_.memory();
DCHECK(mem);
return static_cast<GamepadHardwareBuffer*>(mem);
}
} // namespace content
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