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CoreAudio: Avoid occasional deadlocks when calling AudioDeviceStart

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reuk 2022-07-26 16:31:36 +01:00
parent 5d328f2038
commit 455c865d37
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GPG key ID: 9ADCD339CFC98A11
1 changed files with 71 additions and 22 deletions
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93
modules/juce_audio_devices/native/juce_mac_CoreAudio.cpp
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@ -692,28 +692,36 @@ public:
callback->audioDeviceAboutToStart (&owner);
}
if (! started)
if (scopedProcID.get() == nullptr && deviceID != 0)
{
if (deviceID != 0)
scopedProcID = [&self = *this,
&lock = callbackLock,
nextProcID = ScopedAudioDeviceIOProcID { *this, deviceID, audioIOProc },
deviceID = deviceID]() mutable -> ScopedAudioDeviceIOProcID
{
if (OK (AudioDeviceCreateIOProcID (deviceID, audioIOProc, this, &audioProcID)))
// It *looks* like AudioDeviceStart may start the audio callback running, and then
// immediately lock an internal mutex.
// The same mutex is locked before calling the audioIOProc.
// If we get very unlucky, then we can end up with thread A taking the callbackLock
// and calling AudioDeviceStart, followed by thread B taking the CoreAudio lock
// and calling into audioIOProc, which waits on the callbackLock. When thread A
// continues it attempts to take the CoreAudio lock, and the program deadlocks.
if (auto* procID = nextProcID.get())
{
if (OK (AudioDeviceStart (deviceID, audioProcID)))
{
started = true;
}
else
{
OK (AudioDeviceDestroyIOProcID (deviceID, audioProcID));
audioProcID = {};
}
const ScopedUnlock su (lock);
if (self.OK (AudioDeviceStart (deviceID, procID)))
return std::move (nextProcID);
}
}
return {};
}();
}
playing = started && callback != nullptr;
playing = scopedProcID.get() != nullptr && callback != nullptr;
return started;
return scopedProcID.get() != nullptr;
}
AudioIODeviceCallback* stop (bool leaveInterruptRunning)
@ -722,7 +730,7 @@ public:
auto result = std::exchange (callback, nullptr);
if (started && (deviceID != 0) && ! leaveInterruptRunning)
if (scopedProcID.get() != nullptr && (deviceID != 0) && ! leaveInterruptRunning)
{
audioDeviceStopPending = true;
@ -736,9 +744,7 @@ public:
Thread::sleep (50);
}
OK (AudioDeviceDestroyIOProcID (deviceID, audioProcID));
audioProcID = {};
started = false;
scopedProcID = {};
playing = false;
}
@ -756,7 +762,7 @@ public:
if (audioDeviceStopPending)
{
if (OK (AudioDeviceStop (deviceID, audioProcID)))
if (OK (AudioDeviceStop (deviceID, scopedProcID.get())))
audioDeviceStopPending = false;
return;
@ -841,14 +847,57 @@ public:
StringArray inChanNames, outChanNames;
Array<double> sampleRates;
Array<int> bufferSizes;
AudioDeviceIOProcID audioProcID = {};
private:
class ScopedAudioDeviceIOProcID
{
public:
ScopedAudioDeviceIOProcID() = default;
ScopedAudioDeviceIOProcID (CoreAudioInternal& coreAudio, AudioDeviceID d, AudioDeviceIOProc audioIOProc)
: deviceID (d)
{
if (! coreAudio.OK (AudioDeviceCreateIOProcID (deviceID, audioIOProc, &coreAudio, &proc)))
proc = {};
}
~ScopedAudioDeviceIOProcID() noexcept
{
if (proc != AudioDeviceIOProcID{})
AudioDeviceDestroyIOProcID (deviceID, proc);
}
ScopedAudioDeviceIOProcID (ScopedAudioDeviceIOProcID&& other) noexcept
{
swap (other);
}
ScopedAudioDeviceIOProcID& operator= (ScopedAudioDeviceIOProcID&& other) noexcept
{
ScopedAudioDeviceIOProcID { std::move (other) }.swap (*this);
return *this;
}
AudioDeviceIOProcID get() const { return proc; }
private:
void swap (ScopedAudioDeviceIOProcID& other) noexcept
{
std::swap (other.deviceID, deviceID);
std::swap (other.proc, proc);
}
AudioDeviceID deviceID = {};
AudioDeviceIOProcID proc = {};
};
ScopedAudioDeviceIOProcID scopedProcID;
CoreAudioTimeConversions timeConversions;
AudioIODeviceCallback* callback = nullptr;
CriticalSection callbackLock;
AudioDeviceID deviceID;
bool started = false, audioDeviceStopPending = false;
bool audioDeviceStopPending = false;
std::atomic<bool> playing { false };
double sampleRate = 0;
int bufferSize = 0;