summaryrefslogtreecommitdiffstats
path: root/gfx/layers/apz/public/APZSampler.h
blob: a870c2d688dae5a4b183389cae8163b515412776 (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
/* -*- 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/. */

#ifndef mozilla_layers_APZSampler_h
#define mozilla_layers_APZSampler_h

#include <unordered_map>

#include "apz/src/APZCTreeManager.h"
#include "base/platform_thread.h"  // for PlatformThreadId
#include "mozilla/layers/APZUtils.h"
#include "mozilla/layers/SampleTime.h"
#include "mozilla/StaticMutex.h"
#include "mozilla/StaticPtr.h"
#include "mozilla/webrender/WebRenderTypes.h"
#include "Units.h"
#include "VsyncSource.h"

namespace mozilla {

class TimeStamp;

namespace wr {
struct Transaction;
class TransactionWrapper;
struct WrWindowId;
}  // namespace wr

namespace layers {

struct ScrollbarData;

/**
 * This interface exposes APZ methods related to "sampling" (i.e. reading the
 * async transforms produced by APZ). These methods should all be called on
 * the sampler thread.
 */
class APZSampler {
  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(APZSampler)

 public:
  APZSampler(const RefPtr<APZCTreeManager>& aApz, bool aIsUsingWebRender);

  // Whoever creates this sampler is responsible for calling Destroy() on it
  // before releasing the owning refptr.
  void Destroy();

  void SetWebRenderWindowId(const wr::WindowId& aWindowId);

  /**
   * This function is invoked from rust on the render backend thread when it
   * is created. It effectively tells the APZSampler "the current thread is
   * the sampler thread for this window id" and allows APZSampler to remember
   * which thread it is.
   */
  static void SetSamplerThread(const wr::WrWindowId& aWindowId);
  static void SampleForWebRender(const wr::WrWindowId& aWindowId,
                                 const uint64_t* aGeneratedFrameId,
                                 wr::Transaction* aTransaction);

  void SetSampleTime(const SampleTime& aSampleTime);
  void SampleForWebRender(const Maybe<VsyncId>& aGeneratedFrameId,
                          wr::TransactionWrapper& aTxn);

  /**
   * Similar to above GetCurrentAsyncTransform, but get the current transform
   * with LayersId and ViewID.
   * NOTE: This function should NOT be called on the compositor thread.
   */
  AsyncTransform GetCurrentAsyncTransform(
      const LayersId& aLayersId, const ScrollableLayerGuid::ViewID& aScrollId,
      AsyncTransformComponents aComponents,
      const MutexAutoLock& aProofOfMapLock) const;

  /**
   * Returns the composition bounds of the APZC corresponding to the pair of
   * |aLayersId| and |aScrollId|.
   */
  ParentLayerRect GetCompositionBounds(
      const LayersId& aLayersId, const ScrollableLayerGuid::ViewID& aScrollId,
      const MutexAutoLock& aProofOfMapLock) const;

  struct ScrollOffsetAndRange {
    CSSPoint mOffset;
    CSSRect mRange;
  };
  /**
   * Returns the scroll offset and scroll range of the APZC corresponding to the
   * pair of |aLayersId| and |aScrollId|
   *
   * Note: This is called from OMTA Sampler thread, or Compositor thread for
   * testing.
   */
  Maybe<ScrollOffsetAndRange> GetCurrentScrollOffsetAndRange(
      const LayersId& aLayersId, const ScrollableLayerGuid::ViewID& aScrollId,
      const MutexAutoLock& aProofOfMapLock) const;

  /**
   * This can be used to assert that the current thread is the
   * sampler thread (which samples the async transform).
   * This does nothing if thread assertions are disabled.
   */
  void AssertOnSamplerThread() const;

  /**
   * Returns true if currently on the APZSampler's "sampler thread".
   */
  bool IsSamplerThread() const;

  template <typename Callback>
  void CallWithMapLock(Callback& aCallback) {
    mApz->CallWithMapLock(aCallback);
  }

 protected:
  virtual ~APZSampler();

  static already_AddRefed<APZSampler> GetSampler(
      const wr::WrWindowId& aWindowId);

 private:
  RefPtr<APZCTreeManager> mApz;
  bool mIsUsingWebRender;

  // Used to manage the mapping from a WR window id to APZSampler. These are
  // only used if WebRender is enabled. Both sWindowIdMap and mWindowId should
  // only be used while holding the sWindowIdLock. Note that we use a
  // StaticAutoPtr wrapper on sWindowIdMap to avoid a static initializer for the
  // unordered_map. This also avoids the initializer/memory allocation in cases
  // where we're not using WebRender.
  static StaticMutex sWindowIdLock MOZ_UNANNOTATED;
  static StaticAutoPtr<std::unordered_map<uint64_t, RefPtr<APZSampler>>>
      sWindowIdMap;
  Maybe<wr::WrWindowId> mWindowId;

  // Lock used to protected mSamplerThreadId
  mutable Mutex mThreadIdLock MOZ_UNANNOTATED;
  // If WebRender is enabled, this holds the thread id of the render backend
  // thread (which is the sampler thread) for the compositor associated with
  // this APZSampler instance.
  Maybe<PlatformThreadId> mSamplerThreadId;

  Mutex mSampleTimeLock MOZ_UNANNOTATED;
  // Can only be accessed or modified while holding mSampleTimeLock.
  SampleTime mSampleTime;
};

}  // namespace layers
}  // namespace mozilla

#endif  // mozilla_layers_APZSampler_h