| // Copyright 2018 Google Inc. All Rights Reserved. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| package metrics |
| |
| // This file contains the functionality to represent a build event in respect |
| // to the metric system. A build event corresponds to a block of scoped code |
| // that contains a "Begin()" and immediately followed by "defer End()" trace. |
| // When defined, the duration of the scoped code is measure along with other |
| // performance measurements such as memory. |
| // |
| // As explained in the metrics package, the metrics system is a stacked based |
| // system since the collected metrics is considered to be topline metrics. |
| // The steps of the build system in the UI layer is sequential. Hence, the |
| // functionality defined below follows the stack data structure operations. |
| |
| import ( |
| "os" |
| "syscall" |
| "time" |
| |
| soong_metrics_proto "android/soong/ui/metrics/metrics_proto" |
| "android/soong/ui/tracer" |
| |
| "google.golang.org/protobuf/proto" |
| ) |
| |
| // _now wraps the time.Now() function. _now is declared for unit testing purpose. |
| var _now = func() time.Time { |
| return time.Now() |
| } |
| |
| // event holds the performance metrics data of a single build event. |
| type event struct { |
| // The event name (mostly used for grouping a set of events) |
| name string |
| |
| // The description of the event (used to uniquely identify an event |
| // for metrics analysis). |
| desc string |
| |
| // The time that the event started to occur. |
| start time.Time |
| |
| // The list of process resource information that was executed. |
| procResInfo []*soong_metrics_proto.ProcessResourceInfo |
| } |
| |
| // newEvent returns an event with start populated with the now time. |
| func newEvent(name, desc string) *event { |
| return &event{ |
| name: name, |
| desc: desc, |
| start: _now(), |
| } |
| } |
| |
| func (e event) perfInfo() soong_metrics_proto.PerfInfo { |
| realTime := uint64(_now().Sub(e.start).Nanoseconds()) |
| return soong_metrics_proto.PerfInfo{ |
| Description: proto.String(e.desc), |
| Name: proto.String(e.name), |
| StartTime: proto.Uint64(uint64(e.start.UnixNano())), |
| RealTime: proto.Uint64(realTime), |
| ProcessesResourceInfo: e.procResInfo, |
| } |
| } |
| |
| // EventTracer is an array of events that provides functionality to trace a |
| // block of code on time and performance. The End call expects the Begin is |
| // invoked, otherwise panic is raised. |
| type EventTracer []*event |
| |
| // empty returns true if there are no pending events. |
| func (t *EventTracer) empty() bool { |
| return len(*t) == 0 |
| } |
| |
| // lastIndex returns the index of the last element of events. |
| func (t *EventTracer) lastIndex() int { |
| return len(*t) - 1 |
| } |
| |
| // peek returns the active build event. |
| func (t *EventTracer) peek() *event { |
| return (*t)[t.lastIndex()] |
| } |
| |
| // push adds the active build event in the stack. |
| func (t *EventTracer) push(e *event) { |
| *t = append(*t, e) |
| } |
| |
| // pop removes the active event from the stack since the event has completed. |
| // A panic is raised if there are no pending events. |
| func (t *EventTracer) pop() *event { |
| if t.empty() { |
| panic("Internal error: No pending events") |
| } |
| e := (*t)[t.lastIndex()] |
| *t = (*t)[:t.lastIndex()] |
| return e |
| } |
| |
| // AddProcResInfo adds information on an executed process such as max resident |
| // set memory and the number of voluntary context switches. |
| func (t *EventTracer) AddProcResInfo(name string, state *os.ProcessState) { |
| if t.empty() { |
| return |
| } |
| |
| rusage := state.SysUsage().(*syscall.Rusage) |
| e := t.peek() |
| e.procResInfo = append(e.procResInfo, &soong_metrics_proto.ProcessResourceInfo{ |
| Name: proto.String(name), |
| UserTimeMicros: proto.Uint64(uint64(rusage.Utime.Usec)), |
| SystemTimeMicros: proto.Uint64(uint64(rusage.Stime.Usec)), |
| MinorPageFaults: proto.Uint64(uint64(rusage.Minflt)), |
| MajorPageFaults: proto.Uint64(uint64(rusage.Majflt)), |
| // ru_inblock and ru_oublock are measured in blocks of 512 bytes. |
| IoInputKb: proto.Uint64(uint64(rusage.Inblock / 2)), |
| IoOutputKb: proto.Uint64(uint64(rusage.Oublock / 2)), |
| VoluntaryContextSwitches: proto.Uint64(uint64(rusage.Nvcsw)), |
| InvoluntaryContextSwitches: proto.Uint64(uint64(rusage.Nivcsw)), |
| }) |
| } |
| |
| // Begin starts tracing the event. |
| func (t *EventTracer) Begin(name, desc string, _ tracer.Thread) { |
| t.push(newEvent(name, desc)) |
| } |
| |
| // End performs post calculations such as duration of the event, aggregates |
| // the collected performance information into PerfInfo protobuf message. |
| func (t *EventTracer) End(tracer.Thread) soong_metrics_proto.PerfInfo { |
| return t.pop().perfInfo() |
| } |