fix panic of the future using a mutex instead of some atomic calls + more docs

This commit is contained in:
Adrien Delorme 2018-09-06 18:12:15 +02:00
parent 8a851efcc8
commit 0ac7b64364
1 changed files with 33 additions and 21 deletions

View File

@ -24,17 +24,19 @@ type ProgressBar interface {
// will display the number of current loadings.
// Every call to Start will add total to an internal
// total that is the total displayed.
//
// First call to Start will start a goroutine
// that is waiting for every download to be finished.
// Last call to Finish triggers a cleanup.
// When all active downloads are finished
// StackableProgressBar will clean itself to a default
// state.
type StackableProgressBar struct {
mtx sync.Mutex // locks in Start & Finish
BasicProgressBar
items int32
total int64
started bool
BasicProgressBar
startOnce sync.Once
group sync.WaitGroup
}
var _ ProgressBar = new(StackableProgressBar)
@ -44,21 +46,21 @@ func (spb *StackableProgressBar) start() {
spb.BasicProgressBar.ProgressBar.SetUnits(pb.U_BYTES)
spb.BasicProgressBar.ProgressBar.Start()
go func() {
spb.group.Wait()
spb.BasicProgressBar.ProgressBar.Finish()
spb.startOnce = sync.Once{}
spb.BasicProgressBar.ProgressBar = nil
}()
spb.started = true
}
func (spb *StackableProgressBar) Start(total int64) {
atomic.AddInt64(&spb.total, total)
atomic.AddInt32(&spb.items, 1)
spb.group.Add(1)
spb.startOnce.Do(spb.start)
spb.SetTotal64(atomic.LoadInt64(&spb.total))
spb.mtx.Lock()
spb.total += total
spb.items++
if !spb.started {
spb.start()
}
spb.SetTotal64(spb.total)
spb.prefix()
spb.mtx.Unlock()
}
func (spb *StackableProgressBar) prefix() {
@ -66,9 +68,19 @@ func (spb *StackableProgressBar) prefix() {
}
func (spb *StackableProgressBar) Finish() {
atomic.AddInt32(&spb.items, -1)
spb.group.Done()
spb.mtx.Lock()
spb.items--
if spb.items == 0 {
// slef cleanup
spb.BasicProgressBar.ProgressBar.Finish()
spb.BasicProgressBar.ProgressBar = nil
spb.started = false
spb.total = 0
return
}
spb.prefix()
spb.mtx.Unlock()
}
// BasicProgressBar is packer's basic progress bar.
@ -81,12 +93,12 @@ type BasicProgressBar struct {
var _ ProgressBar = new(BasicProgressBar)
func (bpb *BasicProgressBar) Start(total int64) {
bpb.SetTotal64(int64(total))
bpb.SetTotal64(total)
bpb.ProgressBar.Start()
}
func (bpb *BasicProgressBar) Add(current int64) {
bpb.ProgressBar.Add64(int64(current))
bpb.ProgressBar.Add64(current)
}
func (bpb *BasicProgressBar) NewProxyReader(r io.Reader) io.Reader {
return &ProxyReader{