From d210ebbb09daddb2c8c8e8e77243e088b0b19c4d Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Tue, 26 Sep 2006 23:50:56 +0000 Subject: rework memory block management to be thread-safe and mostly lock-free. pa_memblock is now an opaque structure. Access to its fields is now done through various accessor functions in a thread-safe manner. pa_memblock_acquire() and pa_memblock_release() are now used to access the attached audio data. Why? To allow safe manipulation of the memory pointer maintained by the memory block. Internally _acquire() and _release() maintain a reference counter. Please do not confuse this reference counter whith the one maintained by pa_memblock_ref()/_unref()! As a side effect this patch removes all direct usages of AO_t and replaces it with pa_atomic_xxx based code. This stuff needs some serious testing love. Especially if threads are actively used. git-svn-id: file:///home/lennart/svn/public/pulseaudio/trunk@1404 fefdeb5f-60dc-0310-8127-8f9354f1896f --- src/modules/module-alsa-sink.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) (limited to 'src/modules/module-alsa-sink.c') diff --git a/src/modules/module-alsa-sink.c b/src/modules/module-alsa-sink.c index 6ff9a6e4..7bbd7de2 100644 --- a/src/modules/module-alsa-sink.c +++ b/src/modules/module-alsa-sink.c @@ -144,6 +144,7 @@ static void do_write(struct userdata *u) { update_usage(u); for (;;) { + void *p; pa_memchunk *memchunk = NULL; snd_pcm_sframes_t frames; @@ -156,9 +157,15 @@ static void do_write(struct userdata *u) { memchunk = &u->memchunk; } - assert(memchunk->memblock && memchunk->memblock->data && memchunk->length && memchunk->memblock->length && (memchunk->length % u->frame_size) == 0); + assert(memchunk->memblock); + assert(memchunk->length); + assert((memchunk->length % u->frame_size) == 0); - if ((frames = snd_pcm_writei(u->pcm_handle, (uint8_t*) memchunk->memblock->data + memchunk->index, memchunk->length / u->frame_size)) < 0) { + p = pa_memblock_acquire(memchunk->memblock); + + if ((frames = snd_pcm_writei(u->pcm_handle, (uint8_t*) p + memchunk->index, memchunk->length / u->frame_size)) < 0) { + pa_memblock_release(memchunk->memblock); + if (frames == -EAGAIN) return; @@ -176,6 +183,9 @@ static void do_write(struct userdata *u) { return; } + pa_memblock_release(memchunk->memblock); + + if (memchunk == &u->memchunk) { size_t l = frames * u->frame_size; memchunk->index += l; -- cgit