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1 /*
2  * Copyright 2021 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #pragma once
18 
19 #include <layerproto/LayerProtoHeader.h>
20 
21 #include <atomic>
22 #include <functional>
23 #include <optional>
24 #include <ostream>
25 
26 namespace android {
27 
28 class TransactionTracing;
29 
30 /*
31  * LayerTracing records layer states during surface flinging. Manages tracing state and
32  * configuration.
33  *
34  * The traced data can then be collected with Perfetto.
35  *
36  * The Perfetto custom data source LayerDataSource is registered with perfetto. The data source
37  * is used to listen to perfetto events (setup, start, stop, flush) and to write trace packets
38  * to perfetto.
39  *
40  * The user can configure/start/stop tracing via /system/bin/perfetto.
41  *
42  * Tracing can operate in the following modes.
43  *
44  * ACTIVE mode:
45  * A layers snapshot is taken and written to perfetto for each vsyncid commit.
46  *
47  * GENERATED mode:
48  * Listens to the perfetto 'flush' event (e.g. when a bugreport is taken).
49  * When a 'flush' event is received, the ring buffer of transactions (hold by TransactionTracing)
50  * is processed by LayerTraceGenerator, a sequence of layers snapshots is generated
51  * and written to perfetto.
52  *
53  * DUMP mode:
54  * When the 'start' event is received a single layers snapshot is taken
55  * and written to perfetto.
56  *
57  *
58  * E.g. start active mode tracing
59  * (replace mode value with MODE_DUMP, MODE_GENERATED or MODE_GENERATED_BUGREPORT_ONLY to enable
60  * different tracing modes):
61  *
62    adb shell -t perfetto \
63      -c - --txt \
64      -o /data/misc/perfetto-traces/trace \
65    <<EOF
66    unique_session_name: "surfaceflinger_layers_active"
67    buffers: {
68        size_kb: 63488
69        fill_policy: RING_BUFFER
70    }
71    data_sources: {
72        config {
73            name: "android.surfaceflinger.layers"
74            surfaceflinger_layers_config: {
75                mode: MODE_ACTIVE
76                trace_flags: TRACE_FLAG_INPUT
77                trace_flags: TRACE_FLAG_COMPOSITION
78                trace_flags: TRACE_FLAG_HWC
79                trace_flags: TRACE_FLAG_BUFFERS
80                trace_flags: TRACE_FLAG_VIRTUAL_DISPLAYS
81            }
82        }
83    }
84 EOF
85  *
86  */
87 class LayerTracing {
88 public:
89     using Mode = perfetto::protos::pbzero::SurfaceFlingerLayersConfig::Mode;
90 
91     enum Flag : uint32_t {
92         TRACE_INPUT = 1 << 1,
93         TRACE_COMPOSITION = 1 << 2,
94         TRACE_EXTRA = 1 << 3,
95         TRACE_HWC = 1 << 4,
96         TRACE_BUFFERS = 1 << 5,
97         TRACE_VIRTUAL_DISPLAYS = 1 << 6,
98         TRACE_ALL = TRACE_INPUT | TRACE_COMPOSITION | TRACE_EXTRA,
99     };
100 
101     LayerTracing();
102     LayerTracing(std::ostream&);
103     ~LayerTracing();
104     void setTakeLayersSnapshotProtoFunction(
105             const std::function<perfetto::protos::LayersSnapshotProto(uint32_t)>&);
106     void setTransactionTracing(TransactionTracing&);
107 
108     // Start event from perfetto data source
109     void onStart(Mode mode, uint32_t flags);
110     // Flush event from perfetto data source
111     void onFlush(Mode mode, uint32_t flags, bool isBugreport);
112     // Stop event from perfetto data source
113     void onStop(Mode mode);
114 
115     void addProtoSnapshotToOstream(perfetto::protos::LayersSnapshotProto&& snapshot, Mode mode);
116     bool isActiveTracingStarted() const;
117     uint32_t getActiveTracingFlags() const;
118     bool isActiveTracingFlagSet(Flag flag) const;
119     static perfetto::protos::LayersTraceFileProto createTraceFileProto();
120 
121 private:
122     void writeSnapshotToStream(perfetto::protos::LayersSnapshotProto&& snapshot) const;
123     void writeSnapshotToPerfetto(const perfetto::protos::LayersSnapshotProto& snapshot, Mode mode);
124     bool checkAndUpdateLastVsyncIdWrittenToPerfetto(Mode mode, std::int64_t vsyncId);
125 
126     std::function<perfetto::protos::LayersSnapshotProto(uint32_t)> mTakeLayersSnapshotProto;
127     TransactionTracing* mTransactionTracing;
128 
129     std::atomic<bool> mIsActiveTracingStarted{false};
130     std::atomic<uint32_t> mActiveTracingFlags{0};
131     std::atomic<std::int64_t> mLastVsyncIdWrittenToPerfetto{-1};
132     std::optional<std::reference_wrapper<std::ostream>> mOutStream;
133 };
134 
135 } // namespace android
136