cubeb-coreaudio-rs

Implementation of MacOS Audio backend in CoreAudio framework for Cubeb written in Rust.

Current Goals

• Translate C code line by line into Rust
• Create tests for later refactoring

TODO

• Test aggregate devices
• Test for stream operations
• Clean up the tests. Merge the duplicated pieces in to a function.
• Find a way to catch memory leaks
  • Try Instrument on OSX

Issues

• Mutex: Find a replacement for owned_critical_section
  • a dummy mutex like Mutex<()> should work (see test_dummy_mutex_multithread) as what owned_critical_section does in C version, but it doens't has similar API like assert_current_thread_owns.
  • We implement a OwnedCriticalSection around pthread_mutex_t like what we do in C version for now.
• Unworkable API: dispatch_async
  • The second parameter of dispatch_async is dispatch_block_t, which is defined by typedef void (^dispatch_block_t)(void).
  • The caret symbol ^ defines a block.
  • The block is a lambda expression-like syntax to create closures. (See Apple's document: Working with Blocks)
  • Not sure if Rust can work with it. Rust has its own closure.
  • For now, we implement an API async_dispatch to replace dispatch_async
    • async_dispatch is based on dispatch_async_f.
    • async_dispatch takes a Rust closure (instead of Apple's block) as one of its parameter.
    • prototype on gist
      • The closure (it's a struct) will be boxed, which means the closure will be moved into heap, so the closure cannot be optimized as inline code.
      • Since the closure will be run on an asynchronous thread, we need to move the closure to heap in case it's destroyed when the other thread want to use it.