Add IDevice::close()

[gavv]

Implement explicit closing of devices & files.

sndio::IDevice is an interface implemented by audio devices and files and network senders and receivers. See doxygen. Currently devices perform closing in their destructor. We need to be able to do it explicitly before calling destructor. This is needed for #677.

Steps:

• add virtual status::StatusCode close() = 0 to sndio::IDevice
• add this method to all IDevice implementations
• in implementations in roc::sndio, move closing of file/device from destructor to close(); and in destructor call roc_panic() if close() was not called
• in implementation in roc::pipeline, close() may be no-op (just return StatusOK)
• sndio::Pump should invoke close() before exiting from run()

Related: #703.

[runei]

Hi, I am interested in solving this issue.

[gavv]

Thanks, Leonardo! Be sure to pull fresh develop, it has some recent changes in IDevice.

[runei]

Hi @gavv , what status code should it return in case the device does not close successfully? Or it always return StatusOK?

[gavv]

Hi @gavv , what status code should it return in case the device does not close successfully? Or it always return StatusOK?

Same as from write - ErrFile or ErrDevice depending on device type.