mirror of
https://gitlab.com/pulsechaincom/go-pulse.git
synced 2024-12-25 04:47:17 +00:00
105 lines
2.7 KiB
Go
105 lines
2.7 KiB
Go
// Copyright 2017 The go-ethereum Authors
|
|
// This file is part of the go-ethereum library.
|
|
//
|
|
// The go-ethereum library is free software: you can redistribute it and/or modify
|
|
// it under the terms of the GNU Lesser General Public License as published by
|
|
// the Free Software Foundation, either version 3 of the License, or
|
|
// (at your option) any later version.
|
|
//
|
|
// The go-ethereum library is distributed in the hope that it will be useful,
|
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
// GNU Lesser General Public License for more details.
|
|
//
|
|
// You should have received a copy of the GNU Lesser General Public License
|
|
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
package les
|
|
|
|
import "sync"
|
|
|
|
// execQueue implements a queue that executes function calls in a single thread,
|
|
// in the same order as they have been queued.
|
|
type execQueue struct {
|
|
mu sync.Mutex
|
|
cond *sync.Cond
|
|
funcs []func()
|
|
closeWait chan struct{}
|
|
}
|
|
|
|
// newExecQueue creates a new execution queue.
|
|
func newExecQueue(capacity int) *execQueue {
|
|
q := &execQueue{funcs: make([]func(), 0, capacity)}
|
|
q.cond = sync.NewCond(&q.mu)
|
|
go q.loop()
|
|
return q
|
|
}
|
|
|
|
func (q *execQueue) loop() {
|
|
for f := q.waitNext(false); f != nil; f = q.waitNext(true) {
|
|
f()
|
|
}
|
|
close(q.closeWait)
|
|
}
|
|
|
|
func (q *execQueue) waitNext(drop bool) (f func()) {
|
|
q.mu.Lock()
|
|
if drop && len(q.funcs) > 0 {
|
|
// Remove the function that just executed. We do this here instead of when
|
|
// dequeuing so len(q.funcs) includes the function that is running.
|
|
q.funcs = append(q.funcs[:0], q.funcs[1:]...)
|
|
}
|
|
for !q.isClosed() {
|
|
if len(q.funcs) > 0 {
|
|
f = q.funcs[0]
|
|
break
|
|
}
|
|
q.cond.Wait()
|
|
}
|
|
q.mu.Unlock()
|
|
return f
|
|
}
|
|
|
|
func (q *execQueue) isClosed() bool {
|
|
return q.closeWait != nil
|
|
}
|
|
|
|
// canQueue returns true if more function calls can be added to the execution queue.
|
|
func (q *execQueue) canQueue() bool {
|
|
q.mu.Lock()
|
|
ok := !q.isClosed() && len(q.funcs) < cap(q.funcs)
|
|
q.mu.Unlock()
|
|
return ok
|
|
}
|
|
|
|
// queue adds a function call to the execution queue. Returns true if successful.
|
|
func (q *execQueue) queue(f func()) bool {
|
|
q.mu.Lock()
|
|
ok := !q.isClosed() && len(q.funcs) < cap(q.funcs)
|
|
if ok {
|
|
q.funcs = append(q.funcs, f)
|
|
q.cond.Signal()
|
|
}
|
|
q.mu.Unlock()
|
|
return ok
|
|
}
|
|
|
|
// clear drops all queued functions
|
|
func (q *execQueue) clear() {
|
|
q.mu.Lock()
|
|
q.funcs = q.funcs[:0]
|
|
q.mu.Unlock()
|
|
}
|
|
|
|
// quit stops the exec queue.
|
|
// quit waits for the current execution to finish before returning.
|
|
func (q *execQueue) quit() {
|
|
q.mu.Lock()
|
|
if !q.isClosed() {
|
|
q.closeWait = make(chan struct{})
|
|
q.cond.Signal()
|
|
}
|
|
q.mu.Unlock()
|
|
<-q.closeWait
|
|
}
|