Jörg Höhle : winealsa: Separate read and write pointers.
Module: wine Branch: master Commit: 17f098869fec3f051e6c85d8716fb22cb7bc18e6 URL: http://source.winehq.org/git/wine.git/?a=commit;h=17f098869fec3f051e6c85d871... Author: Jörg Höhle <hoehle(a)users.sourceforge.net> Date: Thu Mar 8 22:47:37 2012 +0100 winealsa: Separate read and write pointers. --- dlls/winealsa.drv/mmdevdrv.c | 53 ++++++++++++++++++++++++++--------------- 1 files changed, 33 insertions(+), 20 deletions(-) diff --git a/dlls/winealsa.drv/mmdevdrv.c b/dlls/winealsa.drv/mmdevdrv.c index e903b9e..3e8ad8d 100644 --- a/dlls/winealsa.drv/mmdevdrv.c +++ b/dlls/winealsa.drv/mmdevdrv.c @@ -118,6 +118,7 @@ struct ACImpl { UINT32 bufsize_frames, held_frames, tmp_buffer_frames, mmdev_period_frames; snd_pcm_uframes_t remapping_buf_frames; UINT32 lcl_offs_frames; /* offs into local_buffer where valid data starts */ + UINT32 wri_offs_frames; /* where to write fresh data in local_buffer */ UINT32 hidden_frames; /* ALSA reserve to ensure continuous rendering */ HANDLE timer; @@ -1960,13 +1961,28 @@ static snd_pcm_sframes_t alsa_write_best_effort(snd_pcm_t *handle, BYTE *buf, return written; } +/* The callback and mmdevapi API functions execute concurrently. + * Shared state & life time after Start: + * This constant until _Release + *->pcm_handle likewise + *->fmt likewise + *->alsa_format, hidden_frames likewise + *->local_buffer, bufsize_frames, alsa_bufsize_frames likewise + *->event Read Only, even constant until _Release(!) + *->started Read Only from cb POV, constant if _Stop kills the cb + * + *->held_frames is the only R/W object. + *->lcl_offs_frames/wri_offs_frames are written by one side exclusively: + * lcl_offs_frames by CaptureClient & write callback + * wri_offs_frames by read callback & RenderClient + */ static void alsa_write_data(ACImpl *This) { snd_pcm_sframes_t written, in_alsa; snd_pcm_uframes_t to_write, avail, write_limit, max_period; int err; BYTE *buf = - This->local_buffer + (This->lcl_offs_frames * This->fmt->nBlockAlign); + This->local_buffer + This->lcl_offs_frames * This->fmt->nBlockAlign; /* this call seems to be required to get an accurate snd_pcm_state() */ avail = snd_pcm_avail_update(This->pcm_handle); @@ -2064,14 +2080,16 @@ static void alsa_write_data(ACImpl *This) static void alsa_read_data(ACImpl *This) { - snd_pcm_sframes_t pos, readable, nread; + snd_pcm_sframes_t nread; + UINT32 pos = This->wri_offs_frames, limit = This->held_frames; - pos = (This->held_frames + This->lcl_offs_frames) % This->bufsize_frames; - readable = This->bufsize_frames - pos; + /* FIXME: Detect overrun and signal DATA_DISCONTINUITY + * How to count overrun frames and report them as position increase? */ + limit = This->bufsize_frames - max(limit, pos); nread = snd_pcm_readi(This->pcm_handle, - This->local_buffer + pos * This->fmt->nBlockAlign, readable); - TRACE("read %ld from %u limit %lu\n", nread, This->held_frames + This->lcl_offs_frames, readable); + This->local_buffer + pos * This->fmt->nBlockAlign, limit); + TRACE("read %ld from %u limit %u\n", nread, pos, limit); if(nread < 0){ int ret; @@ -2087,7 +2105,7 @@ static void alsa_read_data(ACImpl *This) } nread = snd_pcm_readi(This->pcm_handle, - This->local_buffer + pos * This->fmt->nBlockAlign, readable); + This->local_buffer + pos * This->fmt->nBlockAlign, limit); if(nread < 0){ WARN("read failed: %ld (%s)\n", nread, snd_strerror(nread)); return; @@ -2103,14 +2121,9 @@ static void alsa_read_data(ACImpl *This) snd_strerror(err)); } + This->wri_offs_frames += nread; + This->wri_offs_frames %= This->bufsize_frames; This->held_frames += nread; - - if(This->held_frames > This->bufsize_frames){ - WARN("Overflow of unread data\n"); - This->lcl_offs_frames += This->held_frames; - This->lcl_offs_frames %= This->bufsize_frames; - This->held_frames = This->bufsize_frames; - } } static void CALLBACK alsa_push_buffer_data(void *user, BOOLEAN timer) @@ -2256,6 +2269,7 @@ static HRESULT WINAPI AudioClient_Reset(IAudioClient *iface) } This->held_frames = 0; This->lcl_offs_frames = 0; + This->wri_offs_frames = 0; LeaveCriticalSection(&This->lock); @@ -2463,8 +2477,7 @@ static HRESULT WINAPI AudioRenderClient_GetBuffer(IAudioRenderClient *iface, return AUDCLNT_E_BUFFER_TOO_LARGE; } - write_pos = - (This->lcl_offs_frames + This->held_frames) % This->bufsize_frames; + write_pos = This->wri_offs_frames; if(write_pos + frames > This->bufsize_frames){ if(This->tmp_buffer_frames < frames){ HeapFree(GetProcessHeap(), 0, This->tmp_buffer); @@ -2490,8 +2503,7 @@ static HRESULT WINAPI AudioRenderClient_GetBuffer(IAudioRenderClient *iface, static void alsa_wrap_buffer(ACImpl *This, BYTE *buffer, UINT32 written_frames) { - snd_pcm_uframes_t write_offs_frames = - (This->lcl_offs_frames + This->held_frames) % This->bufsize_frames; + snd_pcm_uframes_t write_offs_frames = This->wri_offs_frames; UINT32 write_offs_bytes = write_offs_frames * This->fmt->nBlockAlign; snd_pcm_uframes_t chunk_frames = This->bufsize_frames - write_offs_frames; UINT32 chunk_bytes = chunk_frames * This->fmt->nBlockAlign; @@ -2533,8 +2545,7 @@ static HRESULT WINAPI AudioRenderClient_ReleaseBuffer( } if(This->getbuf_last >= 0) - buffer = This->local_buffer + This->fmt->nBlockAlign * - ((This->lcl_offs_frames + This->held_frames) % This->bufsize_frames); + buffer = This->local_buffer + This->wri_offs_frames * This->fmt->nBlockAlign; else buffer = This->tmp_buffer; @@ -2548,6 +2559,8 @@ static HRESULT WINAPI AudioRenderClient_ReleaseBuffer( if(This->getbuf_last < 0) alsa_wrap_buffer(This, buffer, written_frames); + This->wri_offs_frames += written_frames; + This->wri_offs_frames %= This->bufsize_frames; This->held_frames += written_frames; This->written_frames += written_frames; This->getbuf_last = 0;
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Alexandre Julliard