thread.go (1596B)
1 // Copyright 2018 The Ebiten Authors 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 package thread 16 17 import ( 18 "errors" 19 ) 20 21 // Thread represents an OS thread. 22 type Thread struct { 23 funcs chan func() error 24 results chan error 25 } 26 27 // New creates a new thread. 28 // 29 // It is assumed that the OS thread is fixed by runtime.LockOSThread when New is called. 30 func New() *Thread { 31 return &Thread{ 32 funcs: make(chan func() error), 33 results: make(chan error), 34 } 35 } 36 37 // BreakLoop represents an termination of the loop. 38 var BreakLoop = errors.New("break loop") 39 40 // Loop starts the thread loop until a posted function returns BreakLoop. 41 // 42 // Loop must be called on the thread. 43 func (t *Thread) Loop() { 44 for f := range t.funcs { 45 err := f() 46 if err == BreakLoop { 47 t.results <- nil 48 return 49 } 50 t.results <- err 51 } 52 } 53 54 // Call calls f on the thread. 55 // 56 // Do not call this from the same thread. This would block forever. 57 // 58 // If f returns BreakLoop, Loop returns. 59 // 60 // Call blocks if Loop is not called. 61 func (t *Thread) Call(f func() error) error { 62 t.funcs <- f 63 return <-t.results 64 }