DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Header

Mercurial (c68fe15a81fc)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273
/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "VsyncSource.h"
#include "nsThreadUtils.h"
#include "nsXULAppAPI.h"
#include "mozilla/VsyncDispatcher.h"
#include "MainThreadUtils.h"

namespace mozilla {
namespace gfx {

void VsyncSource::EnableCompositorVsyncDispatcher(
    CompositorVsyncDispatcher* aCompositorVsyncDispatcher) {
  MOZ_ASSERT(XRE_IsParentProcess());
  MOZ_ASSERT(NS_IsMainThread());
  // Just use the global display until we have enough information to get the
  // corresponding display for compositor.
  GetGlobalDisplay().EnableCompositorVsyncDispatcher(
      aCompositorVsyncDispatcher);
}

void VsyncSource::DisableCompositorVsyncDispatcher(
    CompositorVsyncDispatcher* aCompositorVsyncDispatcher) {
  MOZ_ASSERT(XRE_IsParentProcess());
  MOZ_ASSERT(NS_IsMainThread());
  // See also EnableCompositorVsyncDispatcher().
  GetGlobalDisplay().DisableCompositorVsyncDispatcher(
      aCompositorVsyncDispatcher);
}

void VsyncSource::RegisterCompositorVsyncDispatcher(
    CompositorVsyncDispatcher* aCompositorVsyncDispatcher) {
  MOZ_ASSERT(XRE_IsParentProcess());
  MOZ_ASSERT(NS_IsMainThread());
  GetGlobalDisplay().RegisterCompositorVsyncDispatcher(
      aCompositorVsyncDispatcher);
}

void VsyncSource::DeregisterCompositorVsyncDispatcher(
    CompositorVsyncDispatcher* aCompositorVsyncDispatcher) {
  MOZ_ASSERT(XRE_IsParentProcess());
  MOZ_ASSERT(NS_IsMainThread());
  GetGlobalDisplay().DeregisterCompositorVsyncDispatcher(
      aCompositorVsyncDispatcher);
}

void VsyncSource::AddGenericObserver(VsyncObserver* aObserver) {
  MOZ_ASSERT(XRE_IsParentProcess());
  MOZ_ASSERT(NS_IsMainThread());

  GetGlobalDisplay().AddGenericObserver(aObserver);
}

void VsyncSource::RemoveGenericObserver(VsyncObserver* aObserver) {
  MOZ_ASSERT(XRE_IsParentProcess());
  MOZ_ASSERT(NS_IsMainThread());

  GetGlobalDisplay().RemoveGenericObserver(aObserver);
}

void VsyncSource::MoveListenersToNewSource(
    const RefPtr<VsyncSource>& aNewSource) {
  GetGlobalDisplay().MoveListenersToNewSource(aNewSource);
}

RefPtr<RefreshTimerVsyncDispatcher>
VsyncSource::GetRefreshTimerVsyncDispatcher() {
  MOZ_ASSERT(XRE_IsParentProcess());
  // See also AddCompositorVsyncDispatcher().
  return GetGlobalDisplay().GetRefreshTimerVsyncDispatcher();
}

VsyncSource::Display::Display()
    : mDispatcherLock("display dispatcher lock"),
      mRefreshTimerNeedsVsync(false) {
  MOZ_ASSERT(NS_IsMainThread());
  mRefreshTimerVsyncDispatcher = new RefreshTimerVsyncDispatcher(this);
}

VsyncSource::Display::~Display() {
  MOZ_ASSERT(NS_IsMainThread());
  MutexAutoLock lock(mDispatcherLock);
  mRefreshTimerVsyncDispatcher = nullptr;
  MOZ_ASSERT(mRegisteredCompositorVsyncDispatchers.Length() == 0);
  MOZ_ASSERT(mEnabledCompositorVsyncDispatchers.Length() == 0);
}

void VsyncSource::Display::NotifyVsync(TimeStamp aVsyncTimestamp) {
  // Called on the vsync thread
  MutexAutoLock lock(mDispatcherLock);

  // mRefreshTimerVsyncDispatcher might be null here if MoveListenersToNewSource
  // was called concurrently with this function and won the race to acquire
  // mDispatcherLock. In this case the new VsyncSource that is replacing this
  // one will handle notifications from now on, so we can abort.
  if (!mRefreshTimerVsyncDispatcher) {
    return;
  }

  // If the task posted to the main thread from the last NotifyVsync call
  // hasn't been processed yet, then don't send another one. Otherwise we might
  // end up flooding the main thread.
  bool dispatchToMainThread =
      (mLastVsyncIdSentToMainThread == mLastMainThreadProcessedVsyncId);

  mVsyncId = mVsyncId.Next();
  const VsyncEvent event(mVsyncId, aVsyncTimestamp);

  for (size_t i = 0; i < mEnabledCompositorVsyncDispatchers.Length(); i++) {
    mEnabledCompositorVsyncDispatchers[i]->NotifyVsync(event);
  }

  mRefreshTimerVsyncDispatcher->NotifyVsync(event);

  if (dispatchToMainThread) {
    mLastVsyncIdSentToMainThread = mVsyncId;
    NS_DispatchToMainThread(NewRunnableMethod<VsyncEvent>(
        "VsyncSource::Display::NotifyGenericObservers", this,
        &VsyncSource::Display::NotifyGenericObservers, event));
  }
}

void VsyncSource::Display::NotifyGenericObservers(VsyncEvent aEvent) {
  MOZ_ASSERT(NS_IsMainThread());
  for (size_t i = 0; i < mGenericObservers.Length(); i++) {
    mGenericObservers[i]->NotifyVsync(aEvent);
  }

  {  // Scope lock
    MutexAutoLock lock(mDispatcherLock);
    mLastMainThreadProcessedVsyncId = aEvent.mId;
  }
}

TimeDuration VsyncSource::Display::GetVsyncRate() {
  // If hardware queries fail / are unsupported, we have to just guess.
  return TimeDuration::FromMilliseconds(1000.0 / 60.0);
}

void VsyncSource::Display::RegisterCompositorVsyncDispatcher(
    CompositorVsyncDispatcher* aCompositorVsyncDispatcher) {
  MOZ_ASSERT(NS_IsMainThread());
  MOZ_ASSERT(aCompositorVsyncDispatcher);
  {  // scope lock
    MutexAutoLock lock(mDispatcherLock);
    mRegisteredCompositorVsyncDispatchers.AppendElement(
        aCompositorVsyncDispatcher);
  }
}

void VsyncSource::Display::DeregisterCompositorVsyncDispatcher(
    CompositorVsyncDispatcher* aCompositorVsyncDispatcher) {
  MOZ_ASSERT(NS_IsMainThread());
  MOZ_ASSERT(aCompositorVsyncDispatcher);
  {  // Scope lock
    MutexAutoLock lock(mDispatcherLock);
    mRegisteredCompositorVsyncDispatchers.RemoveElement(
        aCompositorVsyncDispatcher);
  }
}

void VsyncSource::Display::EnableCompositorVsyncDispatcher(
    CompositorVsyncDispatcher* aCompositorVsyncDispatcher) {
  MOZ_ASSERT(NS_IsMainThread());
  MOZ_ASSERT(aCompositorVsyncDispatcher);
  {  // scope lock
    MutexAutoLock lock(mDispatcherLock);
    if (!mEnabledCompositorVsyncDispatchers.Contains(
            aCompositorVsyncDispatcher)) {
      mEnabledCompositorVsyncDispatchers.AppendElement(
          aCompositorVsyncDispatcher);
    }
  }
  UpdateVsyncStatus();
}

void VsyncSource::Display::DisableCompositorVsyncDispatcher(
    CompositorVsyncDispatcher* aCompositorVsyncDispatcher) {
  MOZ_ASSERT(NS_IsMainThread());
  MOZ_ASSERT(aCompositorVsyncDispatcher);
  {  // Scope lock
    MutexAutoLock lock(mDispatcherLock);
    if (mEnabledCompositorVsyncDispatchers.Contains(
            aCompositorVsyncDispatcher)) {
      mEnabledCompositorVsyncDispatchers.RemoveElement(
          aCompositorVsyncDispatcher);
    }
  }
  UpdateVsyncStatus();
}

void VsyncSource::Display::AddGenericObserver(VsyncObserver* aObserver) {
  MOZ_ASSERT(NS_IsMainThread());
  MOZ_ASSERT(aObserver);
  mGenericObservers.AppendElement(aObserver);

  UpdateVsyncStatus();
}

void VsyncSource::Display::RemoveGenericObserver(VsyncObserver* aObserver) {
  MOZ_ASSERT(NS_IsMainThread());
  MOZ_ASSERT(aObserver);
  mGenericObservers.RemoveElement(aObserver);

  UpdateVsyncStatus();
}

void VsyncSource::Display::MoveListenersToNewSource(
    const RefPtr<VsyncSource>& aNewSource) {
  MOZ_ASSERT(NS_IsMainThread());
  VsyncSource::Display& aNewDisplay = aNewSource->GetGlobalDisplay();
  MutexAutoLock lock(mDispatcherLock);
  MutexAutoLock newLock(aNewDisplay.mDispatcherLock);
  aNewDisplay.mRegisteredCompositorVsyncDispatchers.AppendElements(
      std::move(mRegisteredCompositorVsyncDispatchers));
  aNewDisplay.mEnabledCompositorVsyncDispatchers.AppendElements(
      std::move(mEnabledCompositorVsyncDispatchers));
  aNewDisplay.mGenericObservers.AppendElements(std::move(mGenericObservers));

  for (size_t i = 0;
       i < aNewDisplay.mRegisteredCompositorVsyncDispatchers.Length(); i++) {
    aNewDisplay.mRegisteredCompositorVsyncDispatchers[i]->MoveToSource(
        aNewSource);
  }

  aNewDisplay.mRefreshTimerVsyncDispatcher = mRefreshTimerVsyncDispatcher;
  mRefreshTimerVsyncDispatcher->MoveToDisplay(&aNewDisplay);
  mRefreshTimerVsyncDispatcher = nullptr;
}

void VsyncSource::Display::NotifyRefreshTimerVsyncStatus(bool aEnable) {
  MOZ_ASSERT(NS_IsMainThread());
  mRefreshTimerNeedsVsync = aEnable;
  UpdateVsyncStatus();
}

void VsyncSource::Display::UpdateVsyncStatus() {
  MOZ_ASSERT(NS_IsMainThread());
  // WARNING: This function SHOULD NOT BE CALLED WHILE HOLDING LOCKS
  // NotifyVsync grabs a lock to dispatch vsync events
  // When disabling vsync, we wait for the underlying thread to stop on some
  // platforms We can deadlock if we wait for the underlying vsync thread to
  // stop while the vsync thread is in NotifyVsync.
  bool enableVsync = false;
  {  // scope lock
    MutexAutoLock lock(mDispatcherLock);
    enableVsync = !mEnabledCompositorVsyncDispatchers.IsEmpty() ||
                  mRefreshTimerNeedsVsync || !mGenericObservers.IsEmpty();
  }

  if (enableVsync) {
    EnableVsync();
  } else {
    DisableVsync();
  }

  if (IsVsyncEnabled() != enableVsync) {
    NS_WARNING("Vsync status did not change.");
  }
}

RefPtr<RefreshTimerVsyncDispatcher>
VsyncSource::Display::GetRefreshTimerVsyncDispatcher() {
  return mRefreshTimerVsyncDispatcher;
}

void VsyncSource::Shutdown() { GetGlobalDisplay().Shutdown(); }

}  // namespace gfx
}  // namespace mozilla