ui/accelerated_widget_mac/display_link_mac.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 "ui/accelerated_widget_mac/display_link_mac.h"
   6
   7 #include "base/logging.h"
   8 #include "base/message_loop/message_loop.h"
   9 #include "base/trace_event/trace_event.h"
  10
  11 namespace base {
  12
  13 template<>
  14 struct ScopedTypeRefTraits<CVDisplayLinkRef> {
  15   static void Retain(CVDisplayLinkRef object) {
  16     CVDisplayLinkRetain(object);
  17   }
  18   static void Release(CVDisplayLinkRef object) {
  19     CVDisplayLinkRelease(object);
  20   }
  21 };
  22
  23 }  // namespace base
  24
  25 namespace ui {
  26
  27 // static
  28 scoped_refptr<DisplayLinkMac> DisplayLinkMac::GetForDisplay(
  29     CGDirectDisplayID display_id) {
  30   // Return the existing display link for this display, if it exists.
  31   DisplayMap::iterator found = display_map_.Get().find(display_id);
  32   if (found != display_map_.Get().end()) {
  33     return found->second;
  34   }
  35
  36   CVReturn ret = kCVReturnSuccess;
  37
  38   base::ScopedTypeRef<CVDisplayLinkRef> display_link;
  39   ret = CVDisplayLinkCreateWithCGDisplay(
  40       display_id,
  41       display_link.InitializeInto());
  42   if (ret != kCVReturnSuccess) {
  43     LOG(ERROR) << "CVDisplayLinkCreateWithActiveCGDisplays failed: " << ret;
  44     return NULL;
  45   }
  46
  47   scoped_refptr<DisplayLinkMac> display_link_mac;
  48   display_link_mac = new DisplayLinkMac(display_id, display_link);
  49   ret = CVDisplayLinkSetOutputCallback(
  50       display_link_mac->display_link_,
  51       &DisplayLinkCallback,
  52       display_link_mac.get());
  53   if (ret != kCVReturnSuccess) {
  54     LOG(ERROR) << "CVDisplayLinkSetOutputCallback failed: " << ret;
  55     return NULL;
  56   }
  57
  58   return display_link_mac;
  59 }
  60
  61 DisplayLinkMac::DisplayLinkMac(
  62     CGDirectDisplayID display_id,
  63     base::ScopedTypeRef<CVDisplayLinkRef> display_link)
  64       : main_thread_task_runner_(
  65             base::MessageLoop::current()->task_runner()),
  66         display_id_(display_id),
  67         display_link_(display_link),
  68         timebase_and_interval_valid_(false) {
  69   DCHECK(display_map_.Get().find(display_id) == display_map_.Get().end());
  70   if (display_map_.Get().empty()) {
  71     CGError register_error = CGDisplayRegisterReconfigurationCallback(
  72         DisplayReconfigurationCallBack, nullptr);
  73     DPLOG_IF(ERROR, register_error != kCGErrorSuccess)
  74         << "CGDisplayRegisterReconfigurationCallback: "
  75         << register_error;
  76   }
  77   display_map_.Get().insert(std::make_pair(display_id_, this));
  78 }
  79
  80 DisplayLinkMac::~DisplayLinkMac() {
  81   StopDisplayLink();
  82
  83   DisplayMap::iterator found = display_map_.Get().find(display_id_);
  84   DCHECK(found != display_map_.Get().end());
  85   DCHECK(found->second == this);
  86   display_map_.Get().erase(found);
  87   if (display_map_.Get().empty()) {
  88     CGError remove_error = CGDisplayRemoveReconfigurationCallback(
  89         DisplayReconfigurationCallBack, nullptr);
  90     DPLOG_IF(ERROR, remove_error != kCGErrorSuccess)
  91         << "CGDisplayRemoveReconfigurationCallback: "
  92         << remove_error;
  93   }
  94 }
  95
  96 bool DisplayLinkMac::GetVSyncParameters(
  97     base::TimeTicks* timebase, base::TimeDelta* interval) {
  98   if (!timebase_and_interval_valid_) {
  99     StartOrContinueDisplayLink();
 100     return false;
 101   }
 102
 103   *timebase = timebase_;
 104   *interval = interval_;
 105   return true;
 106 }
 107
 108 void DisplayLinkMac::Tick(const CVTimeStamp& cv_time) {
 109   TRACE_EVENT0("ui", "DisplayLinkMac::Tick");
 110
 111   // Verify that videoRefreshPeriod is 32 bits.
 112   DCHECK((cv_time.videoRefreshPeriod & ~0xffffFFFFull) == 0ull);
 113
 114   // Verify that the numerator and denominator make some sense.
 115   uint32 numerator = static_cast<uint32>(cv_time.videoRefreshPeriod);
 116   uint32 denominator = cv_time.videoTimeScale;
 117   if (numerator <= 0 || denominator <= 0) {
 118     LOG(WARNING) << "Unexpected numerator or denominator, bailing.";
 119     return;
 120   }
 121
 122   timebase_ = base::TimeTicks::FromInternalValue(
 123       cv_time.hostTime / 1000);
 124   interval_ = base::TimeDelta::FromMicroseconds(
 125       1000000 * static_cast<int64>(numerator) / denominator);
 126   timebase_and_interval_valid_ = true;
 127
 128   StopDisplayLink();
 129 }
 130
 131 void DisplayLinkMac::StartOrContinueDisplayLink() {
 132   if (CVDisplayLinkIsRunning(display_link_))
 133     return;
 134
 135   CVReturn ret = CVDisplayLinkStart(display_link_);
 136   if (ret != kCVReturnSuccess) {
 137     LOG(ERROR) << "CVDisplayLinkStart failed: " << ret;
 138   }
 139 }
 140
 141 void DisplayLinkMac::StopDisplayLink() {
 142   if (!CVDisplayLinkIsRunning(display_link_))
 143     return;
 144
 145   CVReturn ret = CVDisplayLinkStop(display_link_);
 146   if (ret != kCVReturnSuccess) {
 147     LOG(ERROR) << "CVDisplayLinkStop failed: " << ret;
 148   }
 149 }
 150
 151 // static
 152 CVReturn DisplayLinkMac::DisplayLinkCallback(
 153     CVDisplayLinkRef display_link,
 154     const CVTimeStamp* now,
 155     const CVTimeStamp* output_time,
 156     CVOptionFlags flags_in,
 157     CVOptionFlags* flags_out,
 158     void* context) {
 159   TRACE_EVENT0("ui", "DisplayLinkMac::DisplayLinkCallback");
 160   DisplayLinkMac* display_link_mac = static_cast<DisplayLinkMac*>(context);
 161   display_link_mac->main_thread_task_runner_->PostTask(
 162       FROM_HERE,
 163       base::Bind(&DisplayLinkMac::Tick, display_link_mac, *output_time));
 164   return kCVReturnSuccess;
 165 }
 166
 167 // static
 168 void DisplayLinkMac::DisplayReconfigurationCallBack(
 169     CGDirectDisplayID display,
 170     CGDisplayChangeSummaryFlags flags,
 171     void* user_info) {
 172   DisplayMap::iterator found = display_map_.Get().find(display);
 173   if (found == display_map_.Get().end())
 174     return;
 175   DisplayLinkMac* display_link_mac = found->second;
 176   display_link_mac->timebase_and_interval_valid_ = false;
 177 }
 178
 179 // static
 180 base::LazyInstance<DisplayLinkMac::DisplayMap>
 181     DisplayLinkMac::display_map_ = LAZY_INSTANCE_INITIALIZER;
 182
 183 }  // ui
 184