containerd/eventloop/eventloop.go
Alexander Morozov 7332e6e847 Add eventloop package
Signed-off-by: Alexander Morozov <lk4d4@docker.com>
2015-12-16 13:53:03 -08:00

51 lines
1.1 KiB
Go

package eventloop
import (
"runtime"
"sync"
)
// Event is receiving notification from loop with Handle() call.
type Event interface {
Handle()
}
// EventLoop is interface for event loops.
// Start starting events processing
// Send adding event to loop
type EventLoop interface {
Start() error
Send(Event) error
}
// ChanLoop is implementation of EventLoop based on channels.
type ChanLoop struct {
events chan Event
once sync.Once
}
// NewChanLoop returns ChanLoop with internal channel buffer set to q.
func NewChanLoop(q int) EventLoop {
return &ChanLoop{
events: make(chan Event, q),
}
}
// Start starting to read events from channel in separate goroutines.
// All calls after first is no-op.
func (el *ChanLoop) Start() error {
go el.once.Do(func() {
// allocate whole OS thread, so nothing can get scheduled over eventloop
runtime.LockOSThread()
for ev := range el.events {
ev.Handle()
}
})
return nil
}
// Send sends event to channel. Will block if buffer is full.
func (el *ChanLoop) Send(ev Event) error {
el.events <- ev
return nil
}