macOS: cubeb_enumerate_devices seems to crash when airpods are "disconnected"

A user reported that the application crashes when they takes off their airpods while the device is selected as default device.
I tracked this down to cubeb_enumerate_devices.

In particular, we try to reconnect a new default device in the device_collection_changed_cb.
EDIT: the default device is connected and a stream is open before the airpods are taken off

So here's a snippet:

void MyClass::init()
{
	if (int err = cubeb_init(&m_context, "MyContext", nullptr))
	{
		printf("Error in cubeb_init\n");
		return;
	}

	if (int err = cubeb_register_device_collection_changed(m_context, CUBEB_DEVICE_TYPE_OUTPUT, device_collection_changed_cb, this))
	{
		printf("Error in cubeb_register_device_collection_changed\n");
		return;
	}
}

void MyClass::device_collection_changed_cb(cubeb* context, void* user_ptr)
{
	if (context == nullptr) return;

	cubeb_device_collection collection{};

	printf("Begin enumeration\n"); // THIS WAS THE LAST LOG MESSAGE

	int err = cubeb_enumerate_devices(context, CUBEB_DEVICE_TYPE_OUTPUT, &collection);

	// THIS IS NEVER REACHED

	if (err != CUBEB_OK)
	{
		printf("Error in cubeb_enumerate_devices\n");
		return;
	}

	// Do other cool stuff
}

I can't reproduce this. Here's what I tried:

Put the airpods in the ears, it's the default audio output device of the machine
Open an output-only cubeb stream, with a device collection changed handler registered, and a cubeb_enumerate_devices(...) call in this callback (very much like in the snippet).
While the stream is playing, remove the airpods from the ears. This does not trigger the device collection changed, but the audio now plays on the speakers.
Put them in the case, this disconnects the airpods, the device collection changed callback is called, cubeb_enumerate_devices(...); is called.

This works as it should here on macOS 12.5. Maybe it would be possible to get stacks so we can figure out what's going on?

Hi, I'm the user which has the issue in the original post. I tested again on macOS 12.5.1 and the issue only occurs on macOS 13.0 beta. I'm not sure how to provide stacks, should I reproduce the crash on macOS 13 and post the "error report" here?

@Megamouse

If you can attach a debugger, and reproduce the crash, it would be amazing, as I don't have macOS 13 beta yet on a machine. It would go like this:

Get an rpcs build with symbols. Maybe @Megamouse knows what's the best way to get one, or can provide one (short of building it yourself)
Open a terminal, ensure you have lldb. If not, you probably need to install xcode or xcode's additional tools (here I think: https://developer.apple.com/download/all/)
When everything is running and you have the airpods in your ears with sound, find the PID of rpcs (probably pgrep rpcs or ps -ef | grep rpcs, second number from the left), and do the following: lldb -p <pid> where <pid> is the PID of rpcs
Remove the airpods, put them in their case so that they're disconnected, normally at this moment the crash will occur, lldb will return to a command prompt
Type bt all, attach here all the text that's output

Invoking the cubeb APIs from within a cubeb callback is not safe in general, unfortunately. Some combinations of calls/backends may happen to work, but I'd recommend using the device_collection_changed_cb to signal some other thread to re-enumerate and handle any other stream configuration you need to do.

Navigation Menu

Repository navigation

macOS: cubeb_enumerate_devices seems to crash when airpods are "disconnected" #719

Metadata

Assignees

Labels

Type

Fields

Projects

Milestone

Relationships

Development

macOS: cubeb_enumerate_devices seems to crash when airpods are "disconnected" #719

Description

Activity

padenot commented on Aug 22, 2022

mygizli04 commented on Aug 22, 2022

padenot commented on Aug 22, 2022

kinetiknz commented on Sep 21, 2022

Metadata

Metadata

Assignees

Labels

Type

Fields

Projects

Milestone

Relationships

Development

Issue actions