You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 

98 lines
2.2 KiB

/**
* Standalone signaling server for the Nextcloud Spreed app.
* Copyright (C) 2020 struktur AG
*
* @author Joachim Bauch <bauch@struktur.de>
*
* @license GNU AGPL version 3 or any later version
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package signaling
import (
"log"
"reflect"
"runtime"
"runtime/debug"
"sync"
)
// DeferredExecutor will asynchronously execute functions while maintaining
// their order.
type DeferredExecutor struct {
queue chan func()
closeChan chan bool
closed chan bool
closeOnce sync.Once
}
func NewDeferredExecutor(queueSize int) *DeferredExecutor {
if queueSize < 0 {
queueSize = 0
}
result := &DeferredExecutor{
queue: make(chan func(), queueSize),
closeChan: make(chan bool, 1),
closed: make(chan bool, 1),
}
go result.run()
return result
}
func (e *DeferredExecutor) run() {
loop:
for {
select {
case f := <-e.queue:
if f == nil {
break loop
}
f()
case <-e.closeChan:
break loop
}
}
e.closed <- true
}
func getFunctionName(i interface{}) string {
return runtime.FuncForPC(reflect.ValueOf(i).Pointer()).Name()
}
func (e *DeferredExecutor) Execute(f func()) {
defer func() {
if e := recover(); e != nil {
log.Printf("Could not defer function %v: %+v", getFunctionName(f), e)
log.Printf("Called from %s", string(debug.Stack()))
}
}()
e.queue <- f
}
func (e *DeferredExecutor) Close() {
select {
case e.closeChan <- true:
e.closeOnce.Do(func() {
close(e.queue)
})
default:
// Already closed.
}
}
func (e *DeferredExecutor) waitForStop() {
<-e.closed
}