87 lines
2.0 KiB
Go
87 lines
2.0 KiB
Go
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// Copyright 2018 The Ebiten Authors
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package thread
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import (
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"errors"
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)
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// Thread defines threading behavior in Ebiten.
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type Thread interface {
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Call(func() error) error
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Loop()
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}
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// OSThread represents an OS thread.
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type OSThread struct {
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funcs chan func() error
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results chan error
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}
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// NewOSThread creates a new thread.
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//
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// It is assumed that the OS thread is fixed by runtime.LockOSThread when NewOSThread is called.
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func NewOSThread() *OSThread {
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return &OSThread{
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funcs: make(chan func() error),
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results: make(chan error),
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}
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}
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// BreakLoop represents an termination of the loop.
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var BreakLoop = errors.New("break loop")
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// Loop starts the thread loop until a posted function returns BreakLoop.
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//
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// Loop must be called on the thread.
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func (t *OSThread) Loop() {
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for f := range t.funcs {
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err := f()
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if err == BreakLoop {
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t.results <- nil
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return
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}
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t.results <- err
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}
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}
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// Call calls f on the thread.
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//
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// Do not call this from the same thread. This would block forever.
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//
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// If f returns BreakLoop, Loop returns.
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//
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// Call blocks if Loop is not called.
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func (t *OSThread) Call(f func() error) error {
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t.funcs <- f
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return <-t.results
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}
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// NoopThread is used to disable threading.
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type NoopThread struct{}
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// NewNoopThread creates a new thread that does no threading.
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func NewNoopThread() *NoopThread {
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return &NoopThread{}
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}
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// Loop does nothing
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func (t *NoopThread) Loop() {}
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// Call executes the func immediately
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func (t *NoopThread) Call(f func() error) error {
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return f()
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}
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