1/* 2 * Copyright (C) 2019 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 17syntax = "proto2"; 18 19import "protos/perfetto/trace/track_event/chrome_process_descriptor.proto"; 20import "protos/perfetto/trace/track_event/chrome_thread_descriptor.proto"; 21import "protos/perfetto/trace/track_event/process_descriptor.proto"; 22import "protos/perfetto/trace/track_event/thread_descriptor.proto"; 23import "protos/perfetto/trace/track_event/counter_descriptor.proto"; 24 25package perfetto.protos; 26 27// Defines a track for TrackEvents. Slices and instant events on the same track 28// will be nested based on their timestamps, see TrackEvent::Type. 29// 30// A TrackDescriptor only needs to be emitted by one trace writer / producer and 31// is valid for the entirety of the trace. To ensure the descriptor isn't lost 32// when the ring buffer wraps, it should be reemitted whenever incremental state 33// is cleared. 34// 35// As a fallback, TrackEvents emitted without an explicit track association will 36// be associated with an implicit trace-global track (uuid = 0), see also 37// |TrackEvent::track_uuid|. It is possible but not necessary to emit a 38// TrackDescriptor for this implicit track. 39// 40// Next id: 9. 41message TrackDescriptor { 42 // Unique ID that identifies this track. This ID is global to the whole trace. 43 // Producers should ensure that it is unlikely to clash with IDs emitted by 44 // other producers. A value of 0 denotes the implicit trace-global track. 45 // 46 // For example, legacy TRACE_EVENT macros may use a hash involving the async 47 // event id + id_scope, pid, and/or tid to compute this ID. 48 optional uint64 uuid = 1; 49 50 // A parent track reference can be used to describe relationships between 51 // tracks. For example, to define an asynchronous track which is scoped to a 52 // specific process, specify the uuid for that process's process track here. 53 // Similarly, to associate a COUNTER_THREAD_TIME_NS counter track with a 54 // thread, specify the uuid for that thread's thread track here. 55 optional uint64 parent_uuid = 5; 56 57 // Name of the track. Optional - if unspecified, it may be derived from the 58 // process/thread name (process/thread tracks), the first event's name (async 59 // tracks), or counter name (counter tracks). 60 optional string name = 2; 61 62 // Associate the track with a process, making it the process-global track. 63 // There should only be one such track per process (usually for instant 64 // events; trace processor uses this fact to detect pid reuse). If you need 65 // more (e.g. for asynchronous events), create child tracks using parent_uuid. 66 // 67 // Trace processor will merge events on a process track with slice-type events 68 // from other sources (e.g. ftrace) for the same process into a single 69 // timeline view. 70 optional ProcessDescriptor process = 3; 71 optional ChromeProcessDescriptor chrome_process = 6; 72 73 // Associate the track with a thread, indicating that the track's events 74 // describe synchronous code execution on the thread. There should only be one 75 // such track per thread (trace processor uses this fact to detect tid reuse). 76 // 77 // Trace processor will merge events on a thread track with slice-type events 78 // from other sources (e.g. ftrace) for the same thread into a single timeline 79 // view. 80 optional ThreadDescriptor thread = 4; 81 optional ChromeThreadDescriptor chrome_thread = 7; 82 83 // Descriptor for a counter track. If set, the track will only support 84 // TYPE_COUNTER TrackEvents (and values provided via TrackEvent's 85 // |extra_counter_values|). 86 optional CounterDescriptor counter = 8; 87} 88