1// Copyright 2018 Google Inc. All Rights Reserved. 2// 3// Licensed under the Apache License, Version 2.0 (the "License"); 4// you may not use this file except in compliance with the License. 5// You may obtain a copy of the License at 6// 7// http://www.apache.org/licenses/LICENSE-2.0 8// 9// Unless required by applicable law or agreed to in writing, software 10// distributed under the License is distributed on an "AS IS" BASIS, 11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12// See the License for the specific language governing permissions and 13// limitations under the License. 14 15package metrics 16 17// This file contains the functionality to represent a build event in respect 18// to the metric system. A build event corresponds to a block of scoped code 19// that contains a "Begin()" and immediately followed by "defer End()" trace. 20// When defined, the duration of the scoped code is measure along with other 21// performance measurements such as memory. 22// 23// As explained in the metrics package, the metrics system is a stacked based 24// system since the collected metrics is considered to be topline metrics. 25// The steps of the build system in the UI layer is sequential. Hence, the 26// functionality defined below follows the stack data structure operations. 27 28import ( 29 "os" 30 "syscall" 31 "time" 32 33 soong_metrics_proto "android/soong/ui/metrics/metrics_proto" 34 35 "google.golang.org/protobuf/proto" 36) 37 38// _now wraps the time.Now() function. _now is declared for unit testing purpose. 39var _now = func() time.Time { 40 return time.Now() 41} 42 43// event holds the performance metrics data of a single build event. 44type event struct { 45 // The event name (mostly used for grouping a set of events) 46 name string 47 48 // The description of the event (used to uniquely identify an event 49 // for metrics analysis). 50 desc string 51 52 nonZeroExitCode bool 53 54 errorMsg *string 55 56 // The time that the event started to occur. 57 start time.Time 58 59 // The list of process resource information that was executed. 60 procResInfo []*soong_metrics_proto.ProcessResourceInfo 61} 62 63// newEvent returns an event with start populated with the now time. 64func newEvent(name, desc string) *event { 65 return &event{ 66 name: name, 67 desc: desc, 68 start: _now(), 69 } 70} 71 72func (e event) perfInfo() soong_metrics_proto.PerfInfo { 73 realTime := uint64(_now().Sub(e.start).Nanoseconds()) 74 perfInfo := soong_metrics_proto.PerfInfo{ 75 Description: proto.String(e.desc), 76 Name: proto.String(e.name), 77 StartTime: proto.Uint64(uint64(e.start.UnixNano())), 78 RealTime: proto.Uint64(realTime), 79 ProcessesResourceInfo: e.procResInfo, 80 NonZeroExit: proto.Bool(e.nonZeroExitCode), 81 } 82 if m := e.errorMsg; m != nil { 83 perfInfo.ErrorMessage = proto.String(*m) 84 } 85 return perfInfo 86} 87 88// EventTracer is an array of events that provides functionality to trace a 89// block of code on time and performance. The End call expects the Begin is 90// invoked, otherwise panic is raised. 91type EventTracer []*event 92 93// empty returns true if there are no pending events. 94func (t *EventTracer) empty() bool { 95 return len(*t) == 0 96} 97 98// lastIndex returns the index of the last element of events. 99func (t *EventTracer) lastIndex() int { 100 return len(*t) - 1 101} 102 103// peek returns the active build event. 104func (t *EventTracer) peek() *event { 105 if t.empty() { 106 return nil 107 } 108 return (*t)[t.lastIndex()] 109} 110 111// push adds the active build event in the stack. 112func (t *EventTracer) push(e *event) { 113 *t = append(*t, e) 114} 115 116// pop removes the active event from the stack since the event has completed. 117// A panic is raised if there are no pending events. 118func (t *EventTracer) pop() *event { 119 if t.empty() { 120 panic("Internal error: No pending events") 121 } 122 e := (*t)[t.lastIndex()] 123 *t = (*t)[:t.lastIndex()] 124 return e 125} 126 127// AddProcResInfo adds information on an executed process such as max resident 128// set memory and the number of voluntary context switches. 129func (t *EventTracer) AddProcResInfo(name string, state *os.ProcessState) { 130 if t.empty() { 131 return 132 } 133 134 rusage := state.SysUsage().(*syscall.Rusage) 135 e := t.peek() 136 e.procResInfo = append(e.procResInfo, &soong_metrics_proto.ProcessResourceInfo{ 137 Name: proto.String(name), 138 UserTimeMicros: proto.Uint64(uint64(state.UserTime().Microseconds())), 139 SystemTimeMicros: proto.Uint64(uint64(state.SystemTime().Microseconds())), 140 MinorPageFaults: proto.Uint64(uint64(rusage.Minflt)), 141 MajorPageFaults: proto.Uint64(uint64(rusage.Majflt)), 142 // ru_inblock and ru_oublock are measured in blocks of 512 bytes. 143 IoInputKb: proto.Uint64(uint64(rusage.Inblock / 2)), 144 IoOutputKb: proto.Uint64(uint64(rusage.Oublock / 2)), 145 VoluntaryContextSwitches: proto.Uint64(uint64(rusage.Nvcsw)), 146 InvoluntaryContextSwitches: proto.Uint64(uint64(rusage.Nivcsw)), 147 }) 148} 149 150// Begin starts tracing the event. 151func (t *EventTracer) Begin(name, desc string) { 152 t.push(newEvent(name, desc)) 153} 154 155// End performs post calculations such as duration of the event, aggregates 156// the collected performance information into PerfInfo protobuf message. 157func (t *EventTracer) End() soong_metrics_proto.PerfInfo { 158 return t.pop().perfInfo() 159} 160