adcf40b30c
This CL reverts the changes made in golang/go#11299. Allowing creation of multiple contexts break the case of multiple third party packages depending on the al bindings. These packages need to make sure that there is a valid current context or initiate and make a context current. Packages racing to create and make a context current is what we would like to avoid. Therefore, al bindings will support only a single context that is initiated during OpenDevice. Fixes golang/go#11385. Change-Id: I662f70e49d12833a545005cf0724cc21f67bea09 Reviewed-on: https://go-review.googlesource.com/12001 Reviewed-by: Nigel Tao <nigeltao@golang.org>
75 lines
1.4 KiB
Go
75 lines
1.4 KiB
Go
// Copyright 2015 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// +build darwin linux
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package al
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import (
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"errors"
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"sync"
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"unsafe"
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)
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var (
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mu sync.Mutex
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device unsafe.Pointer
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context unsafe.Pointer
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)
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// DeviceError returns the last known error from the current device.
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func DeviceError() int32 {
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return alcGetError(device)
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}
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// TODO(jbd): Investigate the cases where multiple audio output
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// devices might be needed.
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// OpenDevice opens the default audio device.
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// Calls to OpenDevice are safe for concurrent use.
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func OpenDevice() error {
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mu.Lock()
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defer mu.Unlock()
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// already opened
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if device != nil {
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return nil
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}
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dev := alcOpenDevice("")
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if dev == nil {
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return errors.New("al: cannot open the default audio device")
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}
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ctx := alcCreateContext(dev, nil)
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if ctx == nil {
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alcCloseDevice(dev)
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return errors.New("al: cannot create a new context")
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}
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if !alcMakeContextCurrent(ctx) {
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alcCloseDevice(dev)
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return errors.New("al: cannot make context current")
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}
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device = dev
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context = ctx
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return nil
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}
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// CloseDevice closes the device and frees related resources.
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// Calls to CloseDevice are safe for concurrent use.
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func CloseDevice() {
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mu.Lock()
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defer mu.Unlock()
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if device == nil {
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return
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}
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alcCloseDevice(device)
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if context != nil {
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alcDestroyContext(context)
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}
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device = nil
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context = nil
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}
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