/usr/share/gocode/src/github.com/mitchellh/multistep/basic_runner.go is in golang-github-mitchellh-multistep-dev 0.0~git20170316.391576a-3.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 | package multistep
import (
"sync"
"sync/atomic"
)
type runState int32
const (
stateIdle runState = iota
stateRunning
stateCancelling
)
// BasicRunner is a Runner that just runs the given slice of steps.
type BasicRunner struct {
// Steps is a slice of steps to run. Once set, this should _not_ be
// modified.
Steps []Step
cancelCh chan struct{}
doneCh chan struct{}
state runState
l sync.Mutex
}
func (b *BasicRunner) Run(state StateBag) {
b.l.Lock()
if b.state != stateIdle {
panic("already running")
}
cancelCh := make(chan struct{})
doneCh := make(chan struct{})
b.cancelCh = cancelCh
b.doneCh = doneCh
b.state = stateRunning
b.l.Unlock()
defer func() {
b.l.Lock()
b.cancelCh = nil
b.doneCh = nil
b.state = stateIdle
close(doneCh)
b.l.Unlock()
}()
// This goroutine listens for cancels and puts the StateCancelled key
// as quickly as possible into the state bag to mark it.
go func() {
select {
case <-cancelCh:
// Flag cancel and wait for finish
state.Put(StateCancelled, true)
<-doneCh
case <-doneCh:
}
}()
for _, step := range b.Steps {
// We also check for cancellation here since we can't be sure
// the goroutine that is running to set it actually ran.
if runState(atomic.LoadInt32((*int32)(&b.state))) == stateCancelling {
state.Put(StateCancelled, true)
break
}
action := step.Run(state)
defer step.Cleanup(state)
if _, ok := state.GetOk(StateCancelled); ok {
break
}
if action == ActionHalt {
state.Put(StateHalted, true)
break
}
}
}
func (b *BasicRunner) Cancel() {
b.l.Lock()
switch b.state {
case stateIdle:
// Not running, so Cancel is... done.
b.l.Unlock()
return
case stateRunning:
// Running, so mark that we cancelled and set the state
close(b.cancelCh)
b.state = stateCancelling
fallthrough
case stateCancelling:
// Already cancelling, so just wait until we're done
ch := b.doneCh
b.l.Unlock()
<-ch
}
}
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