content/browser/device_sensors/device_inertial_sensor_service.cc

   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
  12 namespace content {
  13
  14 DeviceInertialSensorService::DeviceInertialSensorService()
  15     : num_light_readers_(0),
  16       num_motion_readers_(0),
  17       num_orientation_readers_(0),
  18       is_shutdown_(false) {
  19 }
  20
  21 DeviceInertialSensorService::~DeviceInertialSensorService() {
  22 }
  23
  24 DeviceInertialSensorService* DeviceInertialSensorService::GetInstance() {
  25   return base::Singleton<
  26       DeviceInertialSensorService,
  27       base::LeakySingletonTraits<DeviceInertialSensorService>>::get();
  28 }
  29
  30 void DeviceInertialSensorService::AddConsumer(ConsumerType consumer_type) {
  31   if (!ChangeNumberConsumers(consumer_type, 1))
  32     return;
  33
  34   DCHECK(GetNumberConsumers(consumer_type));
  35
  36   if (!data_fetcher_)
  37     data_fetcher_.reset(new DataFetcherSharedMemory);
  38   data_fetcher_->StartFetchingDeviceData(consumer_type);
  39 }
  40
  41 void DeviceInertialSensorService::RemoveConsumer(ConsumerType consumer_type) {
  42   if (!ChangeNumberConsumers(consumer_type, -1))
  43     return;
  44
  45   if (GetNumberConsumers(consumer_type) == 0)
  46     data_fetcher_->StopFetchingDeviceData(consumer_type);
  47 }
  48
  49 bool DeviceInertialSensorService::ChangeNumberConsumers(
  50     ConsumerType consumer_type, int delta) {
  51   DCHECK(thread_checker_.CalledOnValidThread());
  52   if (is_shutdown_)
  53     return false;
  54
  55   switch (consumer_type) {
  56     case CONSUMER_TYPE_MOTION:
  57       num_motion_readers_ += delta;
  58       DCHECK_GE(num_motion_readers_, 0);
  59       return true;
  60     case CONSUMER_TYPE_ORIENTATION:
  61       num_orientation_readers_ += delta;
  62       DCHECK_GE(num_orientation_readers_ , 0);
  63       return true;
  64     case CONSUMER_TYPE_LIGHT:
  65       num_light_readers_ += delta;
  66       DCHECK_GE(num_light_readers_, 0);
  67       return true;
  68     default:
  69       NOTREACHED();
  70   }
  71   return false;
  72 }
  73
  74 int DeviceInertialSensorService::GetNumberConsumers(
  75     ConsumerType consumer_type) const {
  76   switch (consumer_type) {
  77     case CONSUMER_TYPE_MOTION:
  78       return num_motion_readers_;
  79     case CONSUMER_TYPE_ORIENTATION:
  80       return num_orientation_readers_;
  81     case CONSUMER_TYPE_LIGHT:
  82       return num_light_readers_;
  83     default:
  84       NOTREACHED();
  85   }
  86   return 0;
  87 }
  88
  89 base::SharedMemoryHandle
  90 DeviceInertialSensorService::GetSharedMemoryHandleForProcess(
  91     ConsumerType consumer_type, base::ProcessHandle handle) {
  92   DCHECK(thread_checker_.CalledOnValidThread());
  93   return data_fetcher_->GetSharedMemoryHandleForProcess(consumer_type, handle);
  94 }
  95
  96 void DeviceInertialSensorService::Shutdown() {
  97   if (data_fetcher_) {
  98     data_fetcher_->Shutdown();
  99     data_fetcher_.reset();
 100   }
 101   is_shutdown_ = true;
 102 }
 103
 104 void DeviceInertialSensorService::SetDataFetcherForTesting(
 105     DataFetcherSharedMemory* test_data_fetcher) {
 106   if (data_fetcher_)
 107     data_fetcher_->Shutdown();
 108   data_fetcher_.reset(test_data_fetcher);
 109 }
 110
 111 }  // namespace content