Mac: Move DisplayLinkMac from content to ui

This logically belongs in ui::, because Mac views will need to be
synced to their display as well.

There is a bit of ugliness in this change in that the task runner for
display-link callbacks is provided as an argument to creation. It will
be moved to be an argument to a function to add callbacks in an upcoming
patch.

BUG=496484

Review URL: https://codereview.chromium.org/1163353002

Cr-Commit-Position: refs/heads/master@{#333357}

4 files changed, 276 insertions, 2 deletions

diff --git a/ui/accelerated_widget_mac/BUILD.gn b/ui/accelerated_widget_mac/BUILD.gn
index 0c066dd..2ca4299 100644
--- a/ui/accelerated_widget_mac/BUILD.gn
+++ b/ui/accelerated_widget_mac/BUILD.gn
@@ -8,6 +8,8 @@ component("accelerated_widget_mac") {
     "accelerated_widget_mac.h",
     "accelerated_widget_mac.mm",
     "accelerated_widget_mac_export.h",
+    "display_link_mac.cc",
+    "display_link_mac.h",
     "io_surface_context.h",
     "io_surface_context.mm",
     "io_surface_layer.h",
diff --git a/ui/accelerated_widget_mac/accelerated_widget_mac.gyp b/ui/accelerated_widget_mac/accelerated_widget_mac.gyp
index d46b2e629..2e13b11 100644
--- a/ui/accelerated_widget_mac/accelerated_widget_mac.gyp
+++ b/ui/accelerated_widget_mac/accelerated_widget_mac.gyp
@@ -15,12 +15,14 @@
         'accelerated_widget_mac.h',
         'accelerated_widget_mac.mm',
         'accelerated_widget_mac_export.h',
+        'display_link_mac.cc',
+        'display_link_mac.h',
         'io_surface_context.h',
         'io_surface_context.mm',
         'io_surface_layer.h',
         'io_surface_layer.mm',
-        "io_surface_ns_gl_surface.h",
-        "io_surface_ns_gl_surface.mm",
+        'io_surface_ns_gl_surface.h',
+        'io_surface_ns_gl_surface.mm',
         'io_surface_texture.h',
         'io_surface_texture.mm',
         'software_layer.h',
diff --git a/ui/accelerated_widget_mac/display_link_mac.cc b/ui/accelerated_widget_mac/display_link_mac.cc
new file mode 100644
index 0000000..94aa454
--- /dev/null
+++ b/ui/accelerated_widget_mac/display_link_mac.cc
@@ -0,0 +1,185 @@
+// Copyright 2014 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 "ui/accelerated_widget_mac/display_link_mac.h"
+
+#include "base/logging.h"
+#include "base/trace_event/trace_event.h"
+
+namespace base {
+
+template<>
+struct ScopedTypeRefTraits<CVDisplayLinkRef> {
+  static void Retain(CVDisplayLinkRef object) {
+    CVDisplayLinkRetain(object);
+  }
+  static void Release(CVDisplayLinkRef object) {
+    CVDisplayLinkRelease(object);
+  }
+};
+
+}  // namespace base
+
+namespace ui {
+
+// static
+scoped_refptr<DisplayLinkMac> DisplayLinkMac::GetForDisplay(
+    scoped_refptr<base::SingleThreadTaskRunner> main_thread_task_runner,
+    CGDirectDisplayID display_id) {
+  // Return the existing display link for this display, if it exists.
+  DisplayMap::iterator found = display_map_.Get().find(display_id);
+  if (found != display_map_.Get().end()) {
+    return found->second;
+  }
+
+  CVReturn ret = kCVReturnSuccess;
+
+  base::ScopedTypeRef<CVDisplayLinkRef> display_link;
+  ret = CVDisplayLinkCreateWithCGDisplay(
+      display_id,
+      display_link.InitializeInto());
+  if (ret != kCVReturnSuccess) {
+    LOG(ERROR) << "CVDisplayLinkCreateWithActiveCGDisplays failed: " << ret;
+    return NULL;
+  }
+
+  scoped_refptr<DisplayLinkMac> display_link_mac;
+  display_link_mac = new DisplayLinkMac(
+      main_thread_task_runner, display_id, display_link);
+  ret = CVDisplayLinkSetOutputCallback(
+      display_link_mac->display_link_,
+      &DisplayLinkCallback,
+      display_link_mac.get());
+  if (ret != kCVReturnSuccess) {
+    LOG(ERROR) << "CVDisplayLinkSetOutputCallback failed: " << ret;
+    return NULL;
+  }
+
+  return display_link_mac;
+}
+
+DisplayLinkMac::DisplayLinkMac(
+    scoped_refptr<base::SingleThreadTaskRunner> main_thread_task_runner,
+    CGDirectDisplayID display_id,
+    base::ScopedTypeRef<CVDisplayLinkRef> display_link)
+      : main_thread_task_runner_(main_thread_task_runner),
+        display_id_(display_id),
+        display_link_(display_link),
+        timebase_and_interval_valid_(false) {
+  DCHECK(display_map_.Get().find(display_id) == display_map_.Get().end());
+  if (display_map_.Get().empty()) {
+    CGError register_error = CGDisplayRegisterReconfigurationCallback(
+        DisplayReconfigurationCallBack, nullptr);
+    DPLOG_IF(ERROR, register_error != kCGErrorSuccess)
+        << "CGDisplayRegisterReconfigurationCallback: "
+        << register_error;
+  }
+  display_map_.Get().insert(std::make_pair(display_id_, this));
+}
+
+DisplayLinkMac::~DisplayLinkMac() {
+  StopDisplayLink();
+
+  DisplayMap::iterator found = display_map_.Get().find(display_id_);
+  DCHECK(found != display_map_.Get().end());
+  DCHECK(found->second == this);
+  display_map_.Get().erase(found);
+  if (display_map_.Get().empty()) {
+    CGError remove_error = CGDisplayRemoveReconfigurationCallback(
+        DisplayReconfigurationCallBack, nullptr);
+    DPLOG_IF(ERROR, remove_error != kCGErrorSuccess)
+        << "CGDisplayRemoveReconfigurationCallback: "
+        << remove_error;
+  }
+}
+
+bool DisplayLinkMac::GetVSyncParameters(
+    base::TimeTicks* timebase, base::TimeDelta* interval) {
+  if (!timebase_and_interval_valid_) {
+    StartOrContinueDisplayLink();
+    return false;
+  }
+
+  *timebase = timebase_;
+  *interval = interval_;
+  return true;
+}
+
+void DisplayLinkMac::Tick(const CVTimeStamp& cv_time) {
+  TRACE_EVENT0("ui", "DisplayLinkMac::Tick");
+
+  // Verify that videoRefreshPeriod is 32 bits.
+  DCHECK((cv_time.videoRefreshPeriod & ~0xffffFFFFull) == 0ull);
+
+  // Verify that the numerator and denominator make some sense.
+  uint32 numerator = static_cast<uint32>(cv_time.videoRefreshPeriod);
+  uint32 denominator = cv_time.videoTimeScale;
+  if (numerator <= 0 || denominator <= 0) {
+    LOG(WARNING) << "Unexpected numerator or denominator, bailing.";
+    return;
+  }
+
+  timebase_ = base::TimeTicks::FromInternalValue(
+      cv_time.hostTime / 1000);
+  interval_ = base::TimeDelta::FromMicroseconds(
+      1000000 * static_cast<int64>(numerator) / denominator);
+  timebase_and_interval_valid_ = true;
+
+  StopDisplayLink();
+}
+
+void DisplayLinkMac::StartOrContinueDisplayLink() {
+  if (CVDisplayLinkIsRunning(display_link_))
+    return;
+
+  CVReturn ret = CVDisplayLinkStart(display_link_);
+  if (ret != kCVReturnSuccess) {
+    LOG(ERROR) << "CVDisplayLinkStart failed: " << ret;
+  }
+}
+
+void DisplayLinkMac::StopDisplayLink() {
+  if (!CVDisplayLinkIsRunning(display_link_))
+    return;
+
+  CVReturn ret = CVDisplayLinkStop(display_link_);
+  if (ret != kCVReturnSuccess) {
+    LOG(ERROR) << "CVDisplayLinkStop failed: " << ret;
+  }
+}
+
+// static
+CVReturn DisplayLinkMac::DisplayLinkCallback(
+    CVDisplayLinkRef display_link,
+    const CVTimeStamp* now,
+    const CVTimeStamp* output_time,
+    CVOptionFlags flags_in,
+    CVOptionFlags* flags_out,
+    void* context) {
+  TRACE_EVENT0("ui", "DisplayLinkMac::DisplayLinkCallback");
+  DisplayLinkMac* display_link_mac = static_cast<DisplayLinkMac*>(context);
+  display_link_mac->main_thread_task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(&DisplayLinkMac::Tick, display_link_mac, *output_time));
+  return kCVReturnSuccess;
+}
+
+// static
+void DisplayLinkMac::DisplayReconfigurationCallBack(
+    CGDirectDisplayID display,
+    CGDisplayChangeSummaryFlags flags,
+    void* user_info) {
+  DisplayMap::iterator found = display_map_.Get().find(display);
+  if (found == display_map_.Get().end())
+    return;
+  DisplayLinkMac* display_link_mac = found->second;
+  display_link_mac->timebase_and_interval_valid_ = false;
+}
+
+// static
+base::LazyInstance<DisplayLinkMac::DisplayMap>
+    DisplayLinkMac::display_map_ = LAZY_INSTANCE_INITIALIZER;
+
+}  // ui
+
diff --git a/ui/accelerated_widget_mac/display_link_mac.h b/ui/accelerated_widget_mac/display_link_mac.h
new file mode 100644
index 0000000..24aad6e
--- /dev/null
+++ b/ui/accelerated_widget_mac/display_link_mac.h
@@ -0,0 +1,85 @@
+// Copyright 2014 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.
+
+#ifndef UI_ACCELERATED_WIDGET_MAC_DISPLAY_LINK_MAC_H_
+#define UI_ACCELERATED_WIDGET_MAC_DISPLAY_LINK_MAC_H_
+
+#include <QuartzCore/CVDisplayLink.h>
+#include <map>
+
+#include "base/lazy_instance.h"
+#include "base/mac/scoped_typeref.h"
+#include "base/memory/ref_counted.h"
+#include "base/synchronization/lock.h"
+#include "base/time/time.h"
+#include "base/timer/timer.h"
+#include "ui/accelerated_widget_mac/accelerated_widget_mac_export.h"
+
+namespace ui {
+
+class ACCELERATED_WIDGET_MAC_EXPORT DisplayLinkMac :
+    public base::RefCounted<DisplayLinkMac> {
+ public:
+  static scoped_refptr<DisplayLinkMac> GetForDisplay(
+      scoped_refptr<base::SingleThreadTaskRunner> main_thread_task_runner,
+      CGDirectDisplayID display_id);
+
+  // Get vsync scheduling parameters.
+  bool GetVSyncParameters(
+      base::TimeTicks* timebase,
+      base::TimeDelta* interval);
+
+ private:
+  friend class base::RefCounted<DisplayLinkMac>;
+
+  DisplayLinkMac(
+      scoped_refptr<base::SingleThreadTaskRunner> main_thread_task_runner,
+      CGDirectDisplayID display_id,
+      base::ScopedTypeRef<CVDisplayLinkRef> display_link);
+  virtual ~DisplayLinkMac();
+
+  void StartOrContinueDisplayLink();
+  void StopDisplayLink();
+  void Tick(const CVTimeStamp& time);
+
+  // Called by the system on the display link thread, and posts a call to Tick
+  // to the UI thread.
+  static CVReturn DisplayLinkCallback(
+      CVDisplayLinkRef display_link,
+      const CVTimeStamp* now,
+      const CVTimeStamp* output_time,
+      CVOptionFlags flags_in,
+      CVOptionFlags* flags_out,
+      void* context);
+
+  // This is called whenever the display is reconfigured, and marks that the
+  // vsync parameters must be recalculated.
+  static void DisplayReconfigurationCallBack(
+      CGDirectDisplayID display,
+      CGDisplayChangeSummaryFlags flags,
+      void* user_info);
+
+  // The task runner from which to post tasks to run on the main thread.
+  scoped_refptr<base::SingleThreadTaskRunner> main_thread_task_runner_;
+
+  // The display that this display link is attached to.
+  CGDirectDisplayID display_id_;
+
+  // CVDisplayLink for querying VSync timing info.
+  base::ScopedTypeRef<CVDisplayLinkRef> display_link_;
+
+  // VSync parameters computed during Tick.
+  bool timebase_and_interval_valid_;
+  base::TimeTicks timebase_;
+  base::TimeDelta interval_;
+
+  // Each display link instance consumes a non-negligible number of cycles, so
+  // make all display links on the same screen share the same object.
+  typedef std::map<CGDirectDisplayID, DisplayLinkMac*> DisplayMap;
+  static base::LazyInstance<DisplayMap> display_map_;
+};
+
+}  // ui
+
+#endif  // UI_ACCELERATED_WIDGET_MAC_DISPLAY_LINK_MAC_H_