content/browser/renderer_host/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 "content/browser/renderer_host/display_link_mac.h"
   6
   7 #include "base/logging.h"
   8 #include "base/trace_event/trace_event.h"
   9 #include "content/browser/renderer_host/render_widget_resize_helper.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 content {
  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
  50   ret = CVDisplayLinkSetOutputCallback(
  51       display_link_mac->display_link_,
  52       &DisplayLinkCallback,
  53       display_link_mac.get());
  54   if (ret != kCVReturnSuccess) {
  55     LOG(ERROR) << "CVDisplayLinkSetOutputCallback failed: " << ret;
  56     return NULL;
  57   }
  58
  59   return display_link_mac;
  60 }
  61
  62 DisplayLinkMac::DisplayLinkMac(
  63     CGDirectDisplayID display_id,
  64     base::ScopedTypeRef<CVDisplayLinkRef> display_link)
  65       : display_id_(display_id),
  66         display_link_(display_link),
  67         timebase_and_interval_valid_(false) {
  68   DCHECK(display_map_.Get().find(display_id) == display_map_.Get().end());
  69   if (display_map_.Get().empty()) {
  70     CGError register_error = CGDisplayRegisterReconfigurationCallback(
  71         DisplayReconfigurationCallBack, nullptr);
  72     DPLOG_IF(ERROR, register_error != kCGErrorSuccess)
  73         << "CGDisplayRegisterReconfigurationCallback: "
  74         << register_error;
  75   }
  76   display_map_.Get().insert(std::make_pair(display_id_, this));
  77 }
  78
  79 DisplayLinkMac::~DisplayLinkMac() {
  80   StopDisplayLink();
  81
  82   DisplayMap::iterator found = display_map_.Get().find(display_id_);
  83   DCHECK(found != display_map_.Get().end());
  84   DCHECK(found->second == this);
  85   display_map_.Get().erase(found);
  86   if (display_map_.Get().empty()) {
  87     CGError remove_error = CGDisplayRemoveReconfigurationCallback(
  88         DisplayReconfigurationCallBack, nullptr);
  89     DPLOG_IF(ERROR, remove_error != kCGErrorSuccess)
  90         << "CGDisplayRemoveReconfigurationCallback: "
  91         << remove_error;
  92   }
  93 }
  94
  95 bool DisplayLinkMac::GetVSyncParameters(
  96     base::TimeTicks* timebase, base::TimeDelta* interval) {
  97   if (!timebase_and_interval_valid_) {
  98     StartOrContinueDisplayLink();
  99     return false;
 100   }
 101
 102   *timebase = timebase_;
 103   *interval = interval_;
 104   return true;
 105 }
 106
 107 void DisplayLinkMac::Tick(const CVTimeStamp& cv_time) {
 108   TRACE_EVENT0("browser", "DisplayLinkMac::Tick");
 109
 110   // Verify that videoRefreshPeriod is 32 bits.
 111   DCHECK((cv_time.videoRefreshPeriod & ~0xffffFFFFull) == 0ull);
 112
 113   // Verify that the numerator and denominator make some sense.
 114   uint32 numerator = static_cast<uint32>(cv_time.videoRefreshPeriod);
 115   uint32 denominator = cv_time.videoTimeScale;
 116   if (numerator <= 0 || denominator <= 0) {
 117     LOG(WARNING) << "Unexpected numerator or denominator, bailing.";
 118     return;
 119   }
 120
 121   timebase_ = base::TimeTicks::FromInternalValue(
 122       cv_time.hostTime / 1000);
 123   interval_ = base::TimeDelta::FromMicroseconds(
 124       1000000 * static_cast<int64>(numerator) / denominator);
 125   timebase_and_interval_valid_ = true;
 126
 127   StopDisplayLink();
 128 }
 129
 130 void DisplayLinkMac::StartOrContinueDisplayLink() {
 131   if (CVDisplayLinkIsRunning(display_link_))
 132     return;
 133
 134   CVReturn ret = CVDisplayLinkStart(display_link_);
 135   if (ret != kCVReturnSuccess) {
 136     LOG(ERROR) << "CVDisplayLinkStart failed: " << ret;
 137   }
 138 }
 139
 140 void DisplayLinkMac::StopDisplayLink() {
 141   if (!CVDisplayLinkIsRunning(display_link_))
 142     return;
 143
 144   CVReturn ret = CVDisplayLinkStop(display_link_);
 145   if (ret != kCVReturnSuccess) {
 146     LOG(ERROR) << "CVDisplayLinkStop failed: " << ret;
 147   }
 148 }
 149
 150 // static
 151 CVReturn DisplayLinkMac::DisplayLinkCallback(
 152     CVDisplayLinkRef display_link,
 153     const CVTimeStamp* now,
 154     const CVTimeStamp* output_time,
 155     CVOptionFlags flags_in,
 156     CVOptionFlags* flags_out,
 157     void* context) {
 158   TRACE_EVENT0("browser", "DisplayLinkMac::DisplayLinkCallback");
 159   DisplayLinkMac* display_link_mac = static_cast<DisplayLinkMac*>(context);
 160   RenderWidgetResizeHelper::Get()->task_runner()->PostTask(
 161       FROM_HERE,
 162       base::Bind(&DisplayLinkMac::Tick, display_link_mac, *output_time));
 163   return kCVReturnSuccess;
 164 }
 165
 166 // static
 167 void DisplayLinkMac::DisplayReconfigurationCallBack(
 168     CGDirectDisplayID display,
 169     CGDisplayChangeSummaryFlags flags,
 170     void* user_info) {
 171   DisplayMap::iterator found = display_map_.Get().find(display);
 172   if (found == display_map_.Get().end())
 173     return;
 174   DisplayLinkMac* display_link_mac = found->second;
 175   display_link_mac->timebase_and_interval_valid_ = false;
 176 }
 177
 178 // static
 179 base::LazyInstance<DisplayLinkMac::DisplayMap>
 180     DisplayLinkMac::display_map_ = LAZY_INSTANCE_INITIALIZER;
 181
 182 }  // content
 183