WASAPI: get the number of available audio devices

README.md

@@ -34,8 +34,7 @@ behavior on every platform.
  * C library. Depends only on the respective backend API libraries and libc.
    Does *not* depend on libstdc++, and does *not* have exceptions, run-time type
    information, or [setjmp](http://latentcontent.net/2007/12/05/libpng-worst-api-ever/).
- * Errors are communicated via return codes, not logging to stdio. This is one
-   of my many complaints against [PortAudio](http://www.portaudio.com/).
+ * Errors are communicated via return codes, not logging to stdio.
  * Supports channel layouts (also known as channel maps), important for
    surround sound applications.
  * Ability to monitor devices and get an event when available devices change.

soundio/soundio.h

@@ -355,7 +355,7 @@ struct SoundIoDevice {
     // PulseAudio allows any value and so reasonable min/max of 0.10 and 4.0
     // are used. You may check that the current backend is PulseAudio and
     // ignore these min/max values.
-    // For JACK, buffer duration and period duration are the same.
+    // For JACK and CoreAudio, buffer duration and period duration are the same.
     double buffer_duration_min;
     double buffer_duration_max;
     double buffer_duration_current;
@@ -420,7 +420,8 @@ struct SoundIoOutStream {
     // actual period duration, as near to this value as possible.
     // Defaults to `buffer_duration / 2` (and then clamped into range).
     // If the device has unknown period duration min and max values, you may
-    // still set this. This value is meaningless for PulseAudio.
+    // still set this. This value is meaningless for PulseAudio, JACK, and
+    // CoreAudio.
     double period_duration;
 
     // Defaults to NULL. Put whatever you want here.
@@ -494,8 +495,7 @@ struct SoundIoInStream {
     // Defaults to 1 second (and then clamped into range). For PulseAudio,
     // defaults to PulseAudio's default value, usually large. If you set this
     // and the backend is PulseAudio, it sets `PA_STREAM_ADJUST_LATENCY` and
-    // is the value used for `maxlength`. With PulseAudio, this value is not
-    // replaced with the actual duration until `soundio_instream_start`.
+    // is the value used for `maxlength`.
     double buffer_duration;
 
     // The latency of the captured audio.
@@ -505,8 +505,6 @@ struct SoundIoInStream {
     // Defaults to `buffer_duration / 8`.
     // If you set this and the backend is PulseAudio, it sets
     // `PA_STREAM_ADJUST_LATENCY` and is the value used for `fragsize`.
-    // With PulseAudio, this value is not replaced with the actual duration
-    // until `soundio_instream_start`.
     double period_duration;
 
     // Defaults to NULL. Put whatever you want here.

src/coreaudio.cpp

@@ -724,6 +724,10 @@ static int refresh_devices(struct SoundIoPrivate *si) {
             rd.device->buffer_duration_min = avr.mMinimum / use_sample_rate;
             rd.device->buffer_duration_max = avr.mMaximum / use_sample_rate;
 
+            rd.device->period_duration_min = rd.device->buffer_duration_min;
+            rd.device->period_duration_max = rd.device->buffer_duration_max;
+            rd.device->period_duration_current = rd.device->buffer_duration_current;
+
 
 
             SoundIoList<SoundIoDevice *> *device_list;
@@ -907,6 +911,8 @@ static int outstream_open_ca(struct SoundIoPrivate *si, struct SoundIoOutStreamP
             outstream->buffer_duration,
             device->buffer_duration_max);
 
+    outstream->period_duration = outstream->outstream->buffer_duration;
+
     AudioComponentDescription desc = {0};
     desc.componentType = kAudioUnitType_Output;
     desc.componentSubType = kAudioUnitSubType_HALOutput;

src/os.cpp

@@ -49,6 +49,7 @@
 
 #include <windows.h>
 #include <mmsystem.h>
+#include <objbase.h>
 
 #else
 
@@ -161,7 +162,10 @@ double soundio_os_get_time(void) {
 #if defined(SOUNDIO_OS_WINDOWS)
 static DWORD WINAPI run_win32_thread(LPVOID userdata) {
     struct SoundIoOsThread *thread = (struct SoundIoOsThread *)userdata;
+    HRESULT err = CoInitializeEx(nullptr, COINIT_MULTITHREADED);
+    assert(err == S_OK);
     thread->run(thread->arg);
+    CoUninitialize();
     return 0;
 }
 #else

src/wasapi.cpp

@@ -1,16 +1,142 @@
 #include "wasapi.hpp"
 #include "soundio.hpp"
 
+#include <stdio.h>
+
+#define INITGUID
+#define CINTERFACE
+#define COBJMACROS
+#define WIN32_LEAN_AND_MEAN
+#include <mmdeviceapi.h>
+
+struct RefreshDevices {
+    IMMDeviceCollection *collection;
+};
+
+static void deinit_refresh_devices(RefreshDevices *rd) {
+    if (rd->collection)
+        IMMDeviceCollection_Release(rd->collection);
+}
+
+static int refresh_devices(SoundIoPrivate *si) {
+    SoundIoWasapi *siw = &si->backend_data.wasapi;
+    RefreshDevices rd = {0};
+    HRESULT hr;
+    if (FAILED(hr = IMMDeviceEnumerator_EnumAudioEndpoints(siw->device_enumerator,
+                    eAll, DEVICE_STATE_ACTIVE, &rd.collection)))
+    {
+        deinit_refresh_devices(&rd);
+        return SoundIoErrorOpeningDevice;
+    }
+
+    UINT device_count;
+    if (FAILED(hr = IMMDeviceCollection_GetCount(rd.collection, &device_count))) {
+        deinit_refresh_devices(&rd);
+        return SoundIoErrorOpeningDevice;
+    }
+
+    // TODO
+    fprintf(stderr, "device count: %d\n", (int) device_count);
+    return 0;
+}
+
+
+static void shutdown_backend(SoundIoPrivate *si, int err) {
+    SoundIo *soundio = &si->pub;
+    SoundIoWasapi *siw = &si->backend_data.wasapi;
+    soundio_os_mutex_lock(siw->mutex);
+    siw->shutdown_err = err;
+    soundio->on_events_signal(soundio);
+    soundio_os_mutex_unlock(siw->mutex);
+}
+
+static void device_thread_run(void *arg) {
+    SoundIoPrivate *si = (SoundIoPrivate *)arg;
+    SoundIo *soundio = &si->pub;
+    SoundIoWasapi *siw = &si->backend_data.wasapi;
+    int err;
+
+    HRESULT hr = CoCreateInstance(CLSID_MMDeviceEnumerator, nullptr,
+            CLSCTX_ALL, IID_IMMDeviceEnumerator, (void**)&siw->device_enumerator);
+    if (FAILED(hr)) {
+        shutdown_backend(si, SoundIoErrorSystemResources);
+        if (!siw->have_devices_flag.exchange(true)) {
+            soundio_os_cond_signal(siw->cond, nullptr);
+            soundio->on_events_signal(soundio);
+        }
+        return;
+    }
+
+
+    for (;;) {
+        if (!siw->abort_flag.test_and_set())
+            break;
+        if (siw->device_scan_queued.exchange(false)) {
+            err = refresh_devices(si);
+            if (err)
+                shutdown_backend(si, err);
+            if (!siw->have_devices_flag.exchange(true)) {
+                soundio_os_cond_signal(siw->cond, nullptr);
+                soundio->on_events_signal(soundio);
+            }
+            if (err)
+                break;
+            soundio_os_cond_signal(siw->cond, nullptr);
+        }
+        soundio_os_cond_wait(siw->cond, nullptr);
+    }
+
+    IMMDeviceEnumerator_Release(siw->device_enumerator);
+    siw->device_enumerator = nullptr;
+}
+
+static void block_until_have_devices(SoundIoWasapi *siw) {
+    if (siw->have_devices_flag.load())
+        return;
+    while (!siw->have_devices_flag.load())
+        soundio_os_cond_wait(siw->cond, nullptr);
+}
+
 static void flush_events_wasapi(struct SoundIoPrivate *si) {
-    soundio_panic("TODO");
+    SoundIo *soundio = &si->pub;
+    SoundIoWasapi *siw = &si->backend_data.wasapi;
+    block_until_have_devices(siw);
+
+    bool change = false;
+    bool cb_shutdown = false;
+    SoundIoDevicesInfo *old_devices_info = nullptr;
+
+    soundio_os_mutex_lock(siw->mutex);
+
+    if (siw->shutdown_err && !siw->emitted_shutdown_cb) {
+        siw->emitted_shutdown_cb = true;
+        cb_shutdown = true;
+    } else if (siw->ready_devices_info) {
+        old_devices_info = si->safe_devices_info;
+        si->safe_devices_info = siw->ready_devices_info;
+        siw->ready_devices_info = nullptr;
+        change = true;
+    }
+
+    soundio_os_mutex_unlock(siw->mutex);
+
+    if (cb_shutdown)
+        soundio->on_backend_disconnect(soundio, siw->shutdown_err);
+    else if (change)
+        soundio->on_devices_change(soundio);
+
+    soundio_destroy_devices_info(old_devices_info);
 }
 
 static void wait_events_wasapi(struct SoundIoPrivate *si) {
-    soundio_panic("TODO");
+    SoundIoWasapi *siw = &si->backend_data.wasapi;
+    flush_events_wasapi(si);
+    soundio_os_cond_wait(siw->cond, nullptr);
 }
 
 static void wakeup_wasapi(struct SoundIoPrivate *si) {
-    soundio_panic("TODO");
+    SoundIoWasapi *siw = &si->backend_data.wasapi;
+    soundio_os_cond_signal(siw->cond, nullptr);
 }
 
 static void outstream_destroy_wasapi(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os) {
@@ -73,10 +199,48 @@ static int instream_end_read_wasapi(struct SoundIoPrivate *si, struct SoundIoInS
 
 
 static void destroy_wasapi(struct SoundIoPrivate *si) {
-    soundio_panic("TODO");
+    SoundIoWasapi *siw = &si->backend_data.wasapi;
+
+    if (siw->thread) {
+        siw->abort_flag.clear();
+        soundio_os_cond_signal(siw->cond, nullptr);
+        soundio_os_thread_destroy(siw->thread);
+    }
+
+    if (siw->cond)
+        soundio_os_cond_destroy(siw->cond);
+
+    if (siw->mutex)
+        soundio_os_mutex_destroy(siw->mutex);
+
+    soundio_destroy_devices_info(siw->ready_devices_info);
 }
 
 int soundio_wasapi_init(SoundIoPrivate *si) {
+    SoundIoWasapi *siw = &si->backend_data.wasapi;
+    int err;
+
+    siw->have_devices_flag.store(false);
+    siw->device_scan_queued.store(true);
+    siw->abort_flag.test_and_set();
+
+    siw->mutex = soundio_os_mutex_create();
+    if (!siw->mutex) {
+        destroy_wasapi(si);
+        return SoundIoErrorNoMem;
+    }
+
+    siw->cond = soundio_os_cond_create();
+    if (!siw->cond) {
+        destroy_wasapi(si);
+        return SoundIoErrorNoMem;
+    }
+
+    if ((err = soundio_os_thread_create(device_thread_run, si, false, &siw->thread))) {
+        destroy_wasapi(si);
+        return err;
+    }
+
     si->destroy = destroy_wasapi;
     si->flush_events = flush_events_wasapi;
     si->wait_events = wait_events_wasapi;

src/wasapi.hpp

@@ -9,6 +9,9 @@
 #define SOUNDIO_WASAPI_HPP
 
 #include "soundio/soundio.h"
+#include "soundio/os.h"
+#include "atomics.hpp"
+struct IMMDeviceEnumerator;
 
 int soundio_wasapi_init(struct SoundIoPrivate *si);
 
@@ -16,6 +19,18 @@ struct SoundIoDeviceWasapi {
 };
 
 struct SoundIoWasapi {
+    SoundIoOsMutex *mutex;
+    SoundIoOsCond *cond;
+    struct SoundIoOsThread *thread;
+    atomic_flag abort_flag;
+    // this one is ready to be read with flush_events. protected by mutex
+    struct SoundIoDevicesInfo *ready_devices_info;
+    atomic_bool have_devices_flag;
+    atomic_bool device_scan_queued;
+    int shutdown_err;
+    bool emitted_shutdown_cb;
+
+    IMMDeviceEnumerator* device_enumerator;
 };
 
 struct SoundIoOutStreamWasapi {