From c5d30341a12284c7aa99794f11c8bdda2fe6c8ba Mon Sep 17 00:00:00 2001 From: David Reid Date: Wed, 22 Aug 2018 11:26:14 +0000 Subject: [PATCH] audio(4): Experiment with non-blocking mode. --- mini_al.h | 85 +++++++++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 77 insertions(+), 8 deletions(-) diff --git a/mini_al.h b/mini_al.h index bcec73c4..04925bbd 100644 --- a/mini_al.h +++ b/mini_al.h @@ -16421,6 +16421,7 @@ mal_result mal_context_init__sndio(mal_context* pContext) /////////////////////////////////////////////////////////////////////////////// #ifdef MAL_HAS_AUDIO4 #include +#include #include #include #include @@ -16740,7 +16741,8 @@ mal_result mal_device_init__audio4(mal_context* pContext, mal_device_type device deviceName = pDeviceID->audio4; } - pDevice->audio4.fd = open(deviceName, (deviceType == mal_device_type_playback) ? O_WRONLY : O_RDONLY, 0); + // 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); } @@ -16995,18 +16997,85 @@ mal_result mal_device__main_loop__audio4(mal_device* pDevice) // Playback. mal_device__read_frames_from_client(pDevice, pDevice->audio4.fragmentSizeInFrames, pDevice->audio4.pIntermediaryBuffer); - int bytesWritten = write(pDevice->audio4.fd, pDevice->audio4.pIntermediaryBuffer, pDevice->audio4.fragmentSizeInFrames * pDevice->internalChannels * mal_get_bytes_per_sample(pDevice->internalFormat)); - if (bytesWritten < 0) { - return mal_post_error(pDevice, MAL_LOG_LEVEL_ERROR, "[audio4] Failed to send data from the client to the device.", MAL_FAILED_TO_SEND_DATA_TO_DEVICE); + // 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); + } + + 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); + if (bytesWritten < 0) { + return mal_post_error(pDevice, MAL_LOG_LEVEL_ERROR, "[audio4] Failed to send data from the client to the device.", MAL_FAILED_TO_SEND_DATA_TO_DEVICE); + } + + if (bytesWritten == 0) { + return mal_post_error(pDevice, MAL_LOG_LEVEL_ERROR, "[audio4] Failed to write any data to the device.", MAL_FAILED_TO_SEND_DATA_TO_DEVICE); + } + + bytesToWrite -= bytesWritten; } } else { // Capture. - int bytesRead = read(pDevice->audio4.fd, pDevice->audio4.pIntermediaryBuffer, pDevice->audio4.fragmentSizeInFrames * mal_get_bytes_per_sample(pDevice->internalFormat)); - if (bytesRead < 0) { - return mal_post_error(pDevice, MAL_LOG_LEVEL_ERROR, "[audio4] Failed to read data from the device to be sent to the client.", MAL_FAILED_TO_READ_DATA_FROM_DEVICE); + 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_uint32 framesRead = (mal_uint32)bytesRead / pDevice->internalChannels / mal_get_bytes_per_sample(pDevice->internalFormat); + size_t totalBytesRead = 0; + size_t bytesToRead = pDevice->audio4.fragmentSizeInFrames * mal_get_bytes_per_frame(pDevice->internalFormat, pDevice->internalChannels); + while (bytesToRead > 0) { + int bytesRead = read(pDevice->audio4.fd, pDevice->audio4.pIntermediaryBuffer, bytesToRead); + if (bytesRead < 0) { + return mal_post_error(pDevice, MAL_LOG_LEVEL_ERROR, "[audio4] Failed to read data from the device to be sent to the client.", MAL_FAILED_TO_READ_DATA_FROM_DEVICE); + } + + if (bytesRead == 0) { + return mal_post_error(pDevice, MAL_LOG_LEVEL_ERROR, "[audio4] Failed to read any data from the device.", MAL_FAILED_TO_READ_DATA_FROM_DEVICE); + } + + bytesToRead -= bytesRead; + totalBytesRead += bytesRead; + } + + mal_uint32 framesRead = (mal_uint32)totalBytesRead / mal_get_bytes_per_frame(pDevice->internalFormat, pDevice->internalChannels); mal_device__send_frames_to_client(pDevice, framesRead, pDevice->audio4.pIntermediaryBuffer); } }