xref: /aosp_15_r20/external/perfetto/src/trace_processor/tp_metatrace.cc (revision 6dbdd20afdafa5e3ca9b8809fa73465d530080dc)
1 /*
2  * Copyright (C) 2020 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 #include "src/trace_processor/tp_metatrace.h"
18 
19 namespace perfetto {
20 namespace trace_processor {
21 namespace metatrace {
22 
23 namespace {
24 
25 using ProtoEnum = protos::pbzero::MetatraceCategories;
MetatraceCategoriesToProtoEnum(MetatraceCategories categories)26 ProtoEnum MetatraceCategoriesToProtoEnum(MetatraceCategories categories) {
27   // Note: these are intentionally chained ifs and not else-ifs as it's possible
28   // for multiple of these if statements to be true.
29   ProtoEnum result = ProtoEnum::NONE;
30   if (categories & MetatraceCategories::QUERY_TIMELINE)
31     result = static_cast<ProtoEnum>(result | ProtoEnum::QUERY_TIMELINE);
32   if (categories & MetatraceCategories::FUNCTION_CALL)
33     result = static_cast<ProtoEnum>(result | ProtoEnum::FUNCTION_CALL);
34   if (categories & MetatraceCategories::QUERY_DETAILED)
35     result = static_cast<ProtoEnum>(result | ProtoEnum::QUERY_DETAILED);
36   if (categories & MetatraceCategories::DB)
37     result = static_cast<ProtoEnum>(result | ProtoEnum::DB);
38   if (categories & MetatraceCategories::API_TIMELINE)
39     result = static_cast<ProtoEnum>(result | ProtoEnum::API_TIMELINE);
40   return result;
41 }
42 
43 }  // namespace
44 
45 Category g_enabled_categories = Category::NONE;
46 
Enable(MetatraceConfig config)47 void Enable(MetatraceConfig config) {
48   g_enabled_categories = MetatraceCategoriesToProtoEnum(config.categories);
49   if (config.override_buffer_size) {
50     RingBuffer::GetInstance()->Resize(config.override_buffer_size);
51   }
52 }
53 
DisableAndReadBuffer(std::function<void (Record *)> fn)54 void DisableAndReadBuffer(std::function<void(Record*)> fn) {
55   g_enabled_categories = Category::NONE;
56   if (!fn)
57     return;
58   RingBuffer::GetInstance()->ReadAll(fn);
59 }
60 
RingBuffer()61 RingBuffer::RingBuffer() : data_(kDefaultCapacity) {
62   static_assert((kDefaultCapacity & (kDefaultCapacity - 1)) == 0,
63                 "Capacity should be a power of 2");
64 }
65 
Resize(size_t requested_capacity)66 void RingBuffer::Resize(size_t requested_capacity) {
67   size_t actual_capacity = 1;
68   while (actual_capacity < requested_capacity)
69     actual_capacity <<= 1;
70   data_.resize(actual_capacity);
71   start_idx_ = 0;
72   write_idx_ = 0;
73 }
74 
ReadAll(std::function<void (Record *)> fn)75 void RingBuffer::ReadAll(std::function<void(Record*)> fn) {
76   // Mark as reading so we don't get reentrancy in obtaining new
77   // trace events.
78   is_reading_ = true;
79 
80   uint64_t start = (write_idx_ - start_idx_) < data_.size()
81                        ? start_idx_
82                        : write_idx_ - data_.size();
83   uint64_t end = write_idx_;
84 
85   // Increment the write index by kCapacity + 1. This ensures that if
86   // ScopedEntry is destoryed in |fn| below, we won't get overwrites
87   // while reading the buffer.
88   // This works because of the logic in ~ScopedEntry and
89   // RingBuffer::HasOverwritten which ensures that we don't overwrite entries
90   // more than kCapcity elements in the past.
91   write_idx_ += data_.size() + 1;
92 
93   for (uint64_t i = start; i < end; ++i) {
94     Record* record = At(i);
95 
96     // If the slice was unfinished for some reason, don't emit it.
97     if (record->duration_ns != 0) {
98       fn(record);
99     }
100   }
101 
102   // Ensure that the start pointer is updated to the write pointer.
103   start_idx_ = write_idx_;
104 
105   // Remove the reading marker.
106   is_reading_ = false;
107 }
108 
109 }  // namespace metatrace
110 }  // namespace trace_processor
111 }  // namespace perfetto
112