platform_build_soong/ui/status/critical_path.go

155 lines
3.9 KiB
Go

// Copyright 2019 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 status
import (
"time"
"android/soong/ui/logger"
)
func NewCriticalPath(log logger.Logger) StatusOutput {
return &criticalPath{
log: log,
running: make(map[*Action]time.Time),
nodes: make(map[string]*node),
clock: osClock{},
}
}
type criticalPath struct {
log logger.Logger
nodes map[string]*node
running map[*Action]time.Time
start, end time.Time
clock clock
}
type clock interface {
Now() time.Time
}
type osClock struct{}
func (osClock) Now() time.Time { return time.Now() }
// A critical path node stores the critical path (the minimum time to build the node and all of its dependencies given
// perfect parallelism) for an node.
type node struct {
action *Action
cumulativeDuration time.Duration
duration time.Duration
input *node
}
func (cp *criticalPath) StartAction(action *Action, counts Counts) {
start := cp.clock.Now()
if cp.start.IsZero() {
cp.start = start
}
cp.running[action] = start
}
func (cp *criticalPath) FinishAction(result ActionResult, counts Counts) {
if start, ok := cp.running[result.Action]; ok {
delete(cp.running, result.Action)
// Determine the input to this edge with the longest cumulative duration
var criticalPathInput *node
for _, input := range result.Action.Inputs {
if x := cp.nodes[input]; x != nil {
if criticalPathInput == nil || x.cumulativeDuration > criticalPathInput.cumulativeDuration {
criticalPathInput = x
}
}
}
end := cp.clock.Now()
duration := end.Sub(start)
cumulativeDuration := duration
if criticalPathInput != nil {
cumulativeDuration += criticalPathInput.cumulativeDuration
}
node := &node{
action: result.Action,
cumulativeDuration: cumulativeDuration,
duration: duration,
input: criticalPathInput,
}
for _, output := range result.Action.Outputs {
cp.nodes[output] = node
}
cp.end = end
}
}
func (cp *criticalPath) Flush() {
criticalPath := cp.criticalPath()
if len(criticalPath) > 0 {
// Log the critical path to the verbose log
criticalTime := criticalPath[0].cumulativeDuration.Round(time.Second)
cp.log.Verbosef("critical path took %s", criticalTime.String())
if !cp.start.IsZero() {
elapsedTime := cp.end.Sub(cp.start).Round(time.Second)
cp.log.Verbosef("elapsed time %s", elapsedTime.String())
if elapsedTime > 0 {
cp.log.Verbosef("perfect parallelism ratio %d%%",
int(float64(criticalTime)/float64(elapsedTime)*100))
}
}
cp.log.Verbose("critical path:")
for i := len(criticalPath) - 1; i >= 0; i-- {
duration := criticalPath[i].duration
duration = duration.Round(time.Second)
seconds := int(duration.Seconds())
cp.log.Verbosef(" %2d:%02d %s",
seconds/60, seconds%60, criticalPath[i].action.Description)
}
}
}
func (cp *criticalPath) Message(level MsgLevel, msg string) {}
func (cp *criticalPath) Write(p []byte) (n int, err error) { return len(p), nil }
func (cp *criticalPath) criticalPath() []*node {
var max *node
// Find the node with the longest critical path
for _, node := range cp.nodes {
if max == nil || node.cumulativeDuration > max.cumulativeDuration {
max = node
}
}
// Follow the critical path back to the leaf node
var criticalPath []*node
node := max
for node != nil {
criticalPath = append(criticalPath, node)
node = node.input
}
return criticalPath
}