Commit fc3ee393 authored by David Reid's avatar David Reid

audio(4): Some tweaks to device IO.

parent c5d30341
......@@ -505,6 +505,7 @@ typedef int mal_result;
#define MAL_ACCESS_DENIED -32
#define MAL_TOO_LARGE -33
#define MAL_DEVICE_UNAVAILABLE -34
#define MAL_TIMEOUT -35
// Standard sample rates.
#define MAL_SAMPLE_RATE_8000 8000
......@@ -16734,6 +16735,7 @@ mal_result mal_device_init__audio4(mal_context* pContext, mal_device_type device
mal_assert(pDevice != NULL);
mal_zero_object(&pDevice->audio4);
pDevice->audio4.fd = -1;
// The first thing to do is open the file.
const char* deviceName = "/dev/audio";
......@@ -16741,7 +16743,6 @@ mal_result mal_device_init__audio4(mal_context* pContext, mal_device_type device
deviceName = pDeviceID->audio4;
}
// TODO: Consider non blocking mode: O_NONBLOCK. Needed for detecting device unplugs.
pDevice->audio4.fd = open(deviceName, ((deviceType == mal_device_type_playback) ? O_WRONLY : O_RDONLY) | O_NONBLOCK, 0);
if (pDevice->audio4.fd == -1) {
return mal_post_error(pDevice, MAL_LOG_LEVEL_ERROR, "[audio4] Failed to open device.", MAL_FAILED_TO_OPEN_BACKEND_DEVICE);
......@@ -16935,6 +16936,10 @@ mal_result mal_device__start_backend__audio4(mal_device* pDevice)
{
mal_assert(pDevice != NULL);
if (pDevice->audio4.fd == -1) {
return MAL_INVALID_ARGS;
}
// The device is started by the next calls to read() and write(). For playback it's simple - just read
// data from the client, then write it to the device with write() which will in turn start the device.
// For capture it's a bit less intuitive - we do nothing (it'll be started automatically by the first
......@@ -16960,6 +16965,10 @@ mal_result mal_device__stop_backend__audio4(mal_device* pDevice)
{
mal_assert(pDevice != NULL);
if (pDevice->audio4.fd == -1) {
return MAL_INVALID_ARGS;
}
#if defined(__NetBSD__)
if (ioctl(pDevice->audio4.fd, AUDIO_FLUSH, 0) < 0) {
return mal_post_error(pDevice, MAL_LOG_LEVEL_ERROR, "[audio4] Failed to stop device. AUDIO_FLUSH failed.", MAL_FAILED_TO_STOP_BACKEND_DEVICE);
......@@ -16981,6 +16990,44 @@ mal_result mal_device__break_main_loop__audio4(mal_device* pDevice)
return MAL_SUCCESS;
}
mal_result mal_device__wait__audio4(mal_device* pDevice)
{
mal_assert(pDevice != NULL);
struct pollfd fds[1];
fds[0].fd = pDevice->audio4.fd;
fds[0].events = (pDevice->type == mal_device_type_playback) ? (POLLOUT | POLLWRBAND) : (POLLIN | POLLPRI);
int timeout = 2 * 1000;
int ioresult = poll(fds, mal_countof(fds), timeout);
if (ioresult < 0) {
#ifdef MAL_DEBUG_OUTPUT
printf("poll() failed: timeout=%d, ioresult=%d\n", pDevice->bufferSizeInMilliseconds, ioresult);
#endif
return mal_post_error(pDevice, MAL_LOG_LEVEL_ERROR, "[audio4] Failed to wait for device.", MAL_ERROR);
}
// Check for a timeout. This has been annoying in my testing. In my testing, when the device is unplugged it will just
// hang on the next calls to write(), ioctl(), etc. The only way I have figured out how to handle this is to wait for
// a timeout from poll(). In the unplugging case poll() will timeout, however there's no indication that the device is
// unusable - no flags are set, no errors are reported, nothing. To work around this I have decided to outright fail
// in the event of a timeout.
if (ioresult == 0) {
// Check for errors.
if ((fds[0].revents & (POLLERR | POLLNVAL)) != 0) {
return mal_post_error(pDevice, MAL_LOG_LEVEL_ERROR, "[audio4] Failed to wait for device.", MAL_NO_DEVICE);
}
if ((fds[0].revents & (POLLHUP)) != 0) {
return mal_post_error(pDevice, MAL_LOG_LEVEL_ERROR, "[audio4] Failed to wait for device. Disconnected.", MAL_NO_DEVICE);
}
// A return value of 0 from poll indicates a timeout.
return mal_post_error(pDevice, MAL_LOG_LEVEL_ERROR, "[audio4] Timeout while waiting for device.", MAL_TIMEOUT);
}
mal_assert(ioresult > 0);
return MAL_SUCCESS;
}
mal_result mal_device__main_loop__audio4(mal_device* pDevice)
{
mal_assert(pDevice != NULL);
......@@ -16998,29 +17045,11 @@ mal_result mal_device__main_loop__audio4(mal_device* pDevice)
mal_device__read_frames_from_client(pDevice, pDevice->audio4.fragmentSizeInFrames, pDevice->audio4.pIntermediaryBuffer);
// Wait for data to become available.
struct pollfd fds[1];
fds[0].fd = pDevice->audio4.fd;
fds[0].events = POLLOUT | POLLWRBAND;
int timeout = 2 * 1000; //mal_calculate_buffer_size_in_milliseconds_from_frames(pDevice->audio4.fragmentSizeInFrames, pDevice->internalSampleRate);
for (;;) {
int ioresult = poll(fds, mal_countof(fds), timeout);
if (ioresult < 0) {
#ifdef MAL_DEBUG_OUTPUT
printf("poll() failed: timeout=%d, ioresult=%d\n", pDevice->bufferSizeInMilliseconds, ioresult);
#endif
return mal_post_error(pDevice, MAL_LOG_LEVEL_ERROR, "[audio4] Failed to wait for device.", MAL_FAILED_TO_SEND_DATA_TO_DEVICE);
}
if (ioresult > 0) {
break;
}
mal_assert(ioresult == 0);
// A return value of 0 from pool indicates a timeout.
return mal_post_error(pDevice, MAL_LOG_LEVEL_ERROR, "[audio4] Timeout while waiting for device.", MAL_FAILED_TO_SEND_DATA_TO_DEVICE);
mal_result result = mal_device__wait__audio4(pDevice);
if (result != MAL_SUCCESS) {
return result;
}
size_t bytesToWrite = pDevice->audio4.fragmentSizeInFrames * mal_get_bytes_per_frame(pDevice->internalFormat, pDevice->internalChannels);
while (bytesToWrite > 0) {
ssize_t bytesWritten = write(pDevice->audio4.fd, pDevice->audio4.pIntermediaryBuffer, bytesToWrite);
......@@ -17036,27 +17065,9 @@ mal_result mal_device__main_loop__audio4(mal_device* pDevice)
}
} else {
// Capture.
struct pollfd fds[1];
fds[0].fd = pDevice->audio4.fd;
fds[0].events = POLLIN | POLLPRI;
int timeout = 2 * 1000; //mal_calculate_buffer_size_in_milliseconds_from_frames(pDevice->audio4.fragmentSizeInFrames, pDevice->internalSampleRate);
for (;;) {
int ioresult = poll(fds, mal_countof(fds), timeout);
if (ioresult < 0) { // 0 = timeout.
#ifdef MAL_DEBUG_OUTPUT
printf("poll() failed: timeout=%d, ioresult=%d\n", pDevice->bufferSizeInMilliseconds, ioresult);
#endif
return mal_post_error(pDevice, MAL_LOG_LEVEL_ERROR, "[audio4] Failed to wait for device.", MAL_FAILED_TO_READ_DATA_FROM_DEVICE);
}
if (ioresult > 0) {
break;
}
mal_assert(ioresult == 0);
// A return value of 0 from pool indicates a timeout.
return mal_post_error(pDevice, MAL_LOG_LEVEL_ERROR, "[audio4] Timeout while waiting for device.", MAL_FAILED_TO_READ_DATA_FROM_DEVICE);
mal_result result = mal_device__wait__audio4(pDevice);
if (result != MAL_SUCCESS) {
return result;
}
size_t totalBytesRead = 0;
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