1// Copyright 2014 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#include "content/browser/device_sensors/device_inertial_sensor_service.h"
6
7#include "base/bind.h"
8#include "base/logging.h"
9#include "base/memory/singleton.h"
10#include "content/browser/device_sensors/data_fetcher_shared_memory.h"
11
12namespace content {
13
14DeviceInertialSensorService::DeviceInertialSensorService()
15    : num_light_readers_(0),
16      num_motion_readers_(0),
17      num_orientation_readers_(0),
18      is_shutdown_(false) {
19}
20
21DeviceInertialSensorService::~DeviceInertialSensorService() {
22}
23
24DeviceInertialSensorService* DeviceInertialSensorService::GetInstance() {
25  return Singleton<DeviceInertialSensorService,
26                   LeakySingletonTraits<DeviceInertialSensorService> >::get();
27}
28
29void DeviceInertialSensorService::AddConsumer(ConsumerType consumer_type) {
30  if (!ChangeNumberConsumers(consumer_type, 1))
31    return;
32
33  DCHECK(GetNumberConsumers(consumer_type));
34
35  if (!data_fetcher_)
36    data_fetcher_.reset(new DataFetcherSharedMemory);
37  data_fetcher_->StartFetchingDeviceData(consumer_type);
38}
39
40void DeviceInertialSensorService::RemoveConsumer(ConsumerType consumer_type) {
41  if (!ChangeNumberConsumers(consumer_type, -1))
42    return;
43
44  if (GetNumberConsumers(consumer_type) == 0)
45    data_fetcher_->StopFetchingDeviceData(consumer_type);
46}
47
48bool DeviceInertialSensorService::ChangeNumberConsumers(
49    ConsumerType consumer_type, int delta) {
50  DCHECK(thread_checker_.CalledOnValidThread());
51  if (is_shutdown_)
52    return false;
53
54  switch (consumer_type) {
55    case CONSUMER_TYPE_MOTION:
56      num_motion_readers_ += delta;
57      DCHECK_GE(num_motion_readers_, 0);
58      return true;
59    case CONSUMER_TYPE_ORIENTATION:
60      num_orientation_readers_ += delta;
61      DCHECK_GE(num_orientation_readers_ , 0);
62      return true;
63    case CONSUMER_TYPE_LIGHT:
64      num_light_readers_ += delta;
65      DCHECK_GE(num_light_readers_, 0);
66      return true;
67    default:
68      NOTREACHED();
69  }
70  return false;
71}
72
73int DeviceInertialSensorService::GetNumberConsumers(
74    ConsumerType consumer_type) const {
75  switch (consumer_type) {
76    case CONSUMER_TYPE_MOTION:
77      return num_motion_readers_;
78    case CONSUMER_TYPE_ORIENTATION:
79      return num_orientation_readers_;
80    case CONSUMER_TYPE_LIGHT:
81      return num_light_readers_;
82    default:
83      NOTREACHED();
84  }
85  return 0;
86}
87
88base::SharedMemoryHandle
89DeviceInertialSensorService::GetSharedMemoryHandleForProcess(
90    ConsumerType consumer_type, base::ProcessHandle handle) {
91  DCHECK(thread_checker_.CalledOnValidThread());
92  return data_fetcher_->GetSharedMemoryHandleForProcess(consumer_type, handle);
93}
94
95void DeviceInertialSensorService::Shutdown() {
96  if (data_fetcher_) {
97    data_fetcher_->StopFetchingAllDeviceData();
98    data_fetcher_.reset();
99  }
100  is_shutdown_ = true;
101}
102
103void DeviceInertialSensorService::SetDataFetcherForTesting(
104    DataFetcherSharedMemory* test_data_fetcher) {
105  if (data_fetcher_)
106    data_fetcher_->StopFetchingAllDeviceData();
107  data_fetcher_.reset(test_data_fetcher);
108}
109
110}  // namespace content
111