This is an implementation of the API described at #204. Please see that issue for more details on the motivation. ----- A **Host** provides access to the available audio devices on the system. Some platforms have more than one host available, e.g. wasapi/asio/dsound on windows, alsa/pulse/jack on linux and so on. As a result, some audio devices are only available on certain hosts, while others are only available on other hosts. Every platform supported by CPAL has at least one **DefaultHost** that is guaranteed to be available (alsa, wasapi and coreaudio). Currently, the default hosts are the only hosts supported by CPAL, however this will change as of landing #221 (cc @freesig). These changes should also accommodate support for other hosts such as jack #250 (cc @derekdreery) and pulseaudio (cc @knappador) #259. This introduces a suite of traits allowing for both compile time and runtime dispatch of different hosts and their uniquely associated device and event loop types. A new private **host** module has been added containing the individual host implementations, each in their own submodule gated to the platforms on which they are available. A new **platform** module has been added containing platform-specific items, including a dynamically dispatched host type that allows for easily switching between hosts at runtime. The **ALL_HOSTS** slice contains a **HostId** for each host supported on the current platform. The **available_hosts** function produces a **HostId** for each host that is currently *available* on the platform. The **host_from_id** function allows for initialising a host from its associated ID, failing with a **HostUnavailable** error. The **default_host** function returns the default host and should never fail. Please see the examples for a demonstration of the change in usage. For the most part, things look the same at the surface level, however the role of device enumeration and creating the event loop have been moved from global functions to host methods. The enumerate.rs example has been updated to enumerate all devices for each host, not just the default. **TODO** - [x] Add the new **Host** API - [x] Update examples for the new API. - [x] ALSA host - [ ] WASAPI host - [ ] CoreAudio host - [ ] Emscripten host **Follow-up PR** - [ ] ASIO host #221 cc @ishitatsuyuki more to review for you if you're interested, but it might be easier after #288 lands and this gets rebased.
36 lines
1.0 KiB
Rust
36 lines
1.0 KiB
Rust
//! Handles COM initialization and cleanup.
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use super::check_result;
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use std::ptr;
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use super::winapi::um::objbase::{COINIT_MULTITHREADED};
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use super::winapi::um::combaseapi::{CoInitializeEx, CoUninitialize};
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thread_local!(static COM_INITIALIZED: ComInitialized = {
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unsafe {
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// this call can fail if another library initialized COM in single-threaded mode
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// handling this situation properly would make the API more annoying, so we just don't care
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check_result(CoInitializeEx(ptr::null_mut(), COINIT_MULTITHREADED)).unwrap();
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ComInitialized(ptr::null_mut())
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}
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});
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/// RAII object that guards the fact that COM is initialized.
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///
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// We store a raw pointer because it's the only way at the moment to remove `Send`/`Sync` from the
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// object.
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struct ComInitialized(*mut ());
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impl Drop for ComInitialized {
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#[inline]
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fn drop(&mut self) {
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unsafe { CoUninitialize() };
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}
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}
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/// Ensures that COM is initialized in this thread.
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#[inline]
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pub fn com_initialized() {
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COM_INITIALIZED.with(|_| {});
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}
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