summaryrefslogtreecommitdiffstats
path: root/gfx/layers/ipc/CompositorThread.cpp
blob: c66de80cfb49ffcb8ad4b06943d228a4678add4e (plain)
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
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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 "CompositorThread.h"

#include "CompositorBridgeParent.h"
#include "gfxGradientCache.h"
#include "MainThreadUtils.h"
#include "VRManagerParent.h"
#include "mozilla/BackgroundHangMonitor.h"
#include "mozilla/SpinEventLoopUntil.h"
#include "mozilla/gfx/gfxVars.h"
#include "mozilla/layers/CanvasTranslator.h"
#include "mozilla/layers/CompositorManagerParent.h"
#include "mozilla/layers/ImageBridgeParent.h"
#include "mozilla/layers/VideoBridgeParent.h"
#include "mozilla/media/MediaSystemResourceService.h"
#include "nsThread.h"
#include "nsThreadUtils.h"

namespace mozilla {
namespace layers {

static StaticRefPtr<CompositorThreadHolder> sCompositorThreadHolder;
static Atomic<bool> sFinishedCompositorShutDown(false);
static mozilla::BackgroundHangMonitor* sBackgroundHangMonitor;
static ProfilerThreadId sProfilerThreadId;

nsISerialEventTarget* CompositorThread() {
  return sCompositorThreadHolder
             ? sCompositorThreadHolder->GetCompositorThread()
             : nullptr;
}

CompositorThreadHolder* CompositorThreadHolder::GetSingleton() {
  return sCompositorThreadHolder;
}

CompositorThreadHolder::CompositorThreadHolder()
    : mCompositorThread(CreateCompositorThread()) {
  MOZ_ASSERT(NS_IsMainThread());
}

CompositorThreadHolder::~CompositorThreadHolder() {
  sFinishedCompositorShutDown = true;
}

/* static */ already_AddRefed<nsIThread>
CompositorThreadHolder::CreateCompositorThread() {
  MOZ_ASSERT(NS_IsMainThread());

  MOZ_ASSERT(!sCompositorThreadHolder,
             "The compositor thread has already been started!");

  // When the CanvasRenderer thread is disabled, WebGL may be handled on this
  // thread, requiring a bigger stack size. See: CanvasManagerParent::Init
  //
  // This is 4M, which is higher than the default 256K.
  // Increased with bug 1753349 to accommodate the `chromium/5359` branch of
  // ANGLE, which has large peak stack usage for some pathological shader
  // compilations.
  //
  // Previously increased to 512K to accommodate Mesa in bug 1753340.
  //
  // Previously increased to 320K to avoid a stack overflow in the
  // Intel Vulkan driver initialization in bug 1716120.
  //
  // Note: we only override it if it's limited already.
  uint32_t stackSize = nsIThreadManager::DEFAULT_STACK_SIZE;
  if (stackSize) {
    stackSize =
        std::max(stackSize, gfx::gfxVars::SupportsThreadsafeGL() &&
                                    !gfx::gfxVars::UseCanvasRenderThread()
                                ? 4096U << 10
                                : 512U << 10);
  }

  nsCOMPtr<nsIThread> compositorThread;
  nsresult rv = NS_NewNamedThread(
      "Compositor", getter_AddRefs(compositorThread),
      NS_NewRunnableFunction(
          "CompositorThreadHolder::CompositorThreadHolderSetup",
          []() {
            sProfilerThreadId = profiler_current_thread_id();
            sBackgroundHangMonitor = new mozilla::BackgroundHangMonitor(
                "Compositor",
                /* Timeout values are powers-of-two to enable us get better
                   data. 128ms is chosen for transient hangs because 8Hz should
                   be the minimally acceptable goal for Compositor
                   responsiveness (normal goal is 60Hz). */
                128,
                /* 2048ms is chosen for permanent hangs because it's longer than
                 * most Compositor hangs seen in the wild, but is short enough
                 * to not miss getting native hang stacks. */
                2048);
            nsCOMPtr<nsIThread> thread = NS_GetCurrentThread();
            static_cast<nsThread*>(thread.get())->SetUseHangMonitor(true);
          }),
      {.stackSize = stackSize});

  if (NS_FAILED(rv)) {
    return nullptr;
  }

  CompositorBridgeParent::Setup();
  ImageBridgeParent::Setup();

  return compositorThread.forget();
}

void CompositorThreadHolder::Start() {
  MOZ_ASSERT(NS_IsMainThread(), "Should be on the main Thread!");
  MOZ_ASSERT(!sCompositorThreadHolder,
             "The compositor thread has already been started!");

  // We unset the holder instead of asserting because failing to start the
  // compositor thread may not be a fatal error. As long as this succeeds in
  // either the GPU process or the UI process, the user will have a usable
  // browser. If we get neither, it will crash as soon as we try to post to the
  // compositor thread for the first time.
  sProfilerThreadId = ProfilerThreadId();
  sCompositorThreadHolder = new CompositorThreadHolder();
  if (!sCompositorThreadHolder->GetCompositorThread()) {
    gfxCriticalNote << "Compositor thread not started ("
                    << XRE_IsParentProcess() << ")";
    sCompositorThreadHolder = nullptr;
  }
}

void CompositorThreadHolder::Shutdown() {
  MOZ_ASSERT(NS_IsMainThread(), "Should be on the main Thread!");
  if (!sCompositorThreadHolder) {
    // We've already shutdown or never started.
    return;
  }

  ImageBridgeParent::Shutdown();
  gfx::VRManagerParent::Shutdown();
  MediaSystemResourceService::Shutdown();
  CompositorManagerParent::Shutdown();
  CanvasTranslator::Shutdown();
  gfx::gfxGradientCache::Shutdown();

  // Ensure there are no pending tasks that would cause an access to the
  // thread's HangMonitor. APZ and Canvas can keep a reference to the compositor
  // thread and may continue to dispatch tasks on it as the system shuts down.
  CompositorThread()->Dispatch(NS_NewRunnableFunction(
      "CompositorThreadHolder::Shutdown",
      [compositorThreadHolder =
           RefPtr<CompositorThreadHolder>(sCompositorThreadHolder),
       backgroundHangMonitor = UniquePtr<mozilla::BackgroundHangMonitor>(
           sBackgroundHangMonitor)]() {
        VideoBridgeParent::UnregisterExternalImages();
        nsCOMPtr<nsIThread> thread = NS_GetCurrentThread();
        static_cast<nsThread*>(thread.get())->SetUseHangMonitor(false);
      }));

  sCompositorThreadHolder = nullptr;
  sBackgroundHangMonitor = nullptr;

  SpinEventLoopUntil("CompositorThreadHolder::Shutdown"_ns, [&]() {
    bool finished = sFinishedCompositorShutDown;
    return finished;
  });

  // At this point, the CompositorThreadHolder instance will have been
  // destroyed, but the compositor thread itself may still be running due to
  // APZ/Canvas code holding a reference to the underlying
  // nsIThread/nsISerialEventTarget. Any tasks scheduled to run on the
  // compositor thread earlier in this function will have been run to
  // completion.
  CompositorBridgeParent::FinishShutdown();
}

/* static */
bool CompositorThreadHolder::IsInCompositorThread() {
  if (!CompositorThread()) {
    return false;
  }
  bool in = false;
  MOZ_ALWAYS_SUCCEEDS(CompositorThread()->IsOnCurrentThread(&in));
  return in;
}

/* static */
ProfilerThreadId CompositorThreadHolder::GetThreadId() {
  return sCompositorThreadHolder ? sProfilerThreadId : ProfilerThreadId();
}

}  // namespace layers
}  // namespace mozilla

bool NS_IsInCompositorThread() {
  return mozilla::layers::CompositorThreadHolder::IsInCompositorThread();
}