ebiten/internal/thread/thread.go
2019-06-08 01:46:06 +09:00

72 lines
1.6 KiB
Go

// Copyright 2018 The Ebiten Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package thread
import (
"context"
"sync/atomic"
)
// Thread represents an OS thread.
type Thread struct {
started int32
funcs chan func()
}
// New creates a new thread.
//
// It is assumed that the OS thread is fixed by runtime.LockOSThread when New is called.
func New() *Thread {
return &Thread{
funcs: make(chan func()),
}
}
// Loop starts the thread loop.
//
// Loop must be called on the thread.
func (t *Thread) Loop(context context.Context) {
atomic.StoreInt32(&t.started, 1)
defer atomic.StoreInt32(&t.started, 0)
loop:
for {
select {
case f := <-t.funcs:
f()
case <-context.Done():
break loop
}
}
}
// Call calls f on the thread.
//
// Do not call this from the same thread. This would block forever.
func (t *Thread) Call(f func() error) error {
if atomic.LoadInt32(&t.started) == 0 {
panic("thread: the thread loop is not started yet")
}
ch := make(chan struct{})
var err error
t.funcs <- func() {
err = f()
close(ch)
}
<-ch
return err
}