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-source.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) (limited to 'src/modules/module-alsa-source.c') diff --git a/src/modules/module-alsa-source.c b/src/modules/module-alsa-source.c index aa0666f1..9bde46da 100644 --- a/src/modules/module-alsa-source.c +++ b/src/modules/module-alsa-source.c @@ -149,6 +149,7 @@ static void do_read(struct userdata *u) { pa_memchunk post_memchunk; snd_pcm_sframes_t frames; size_t l; + void *p; if (!u->memchunk.memblock) { u->memchunk.memblock = pa_memblock_new(u->source->core->mempool, u->memchunk.length = u->fragment_size); @@ -157,11 +158,13 @@ static void do_read(struct userdata *u) { assert(u->memchunk.memblock); assert(u->memchunk.length); - assert(u->memchunk.memblock->data); - assert(u->memchunk.memblock->length); assert(u->memchunk.length % u->frame_size == 0); - if ((frames = snd_pcm_readi(u->pcm_handle, (uint8_t*) u->memchunk.memblock->data + u->memchunk.index, u->memchunk.length / u->frame_size)) < 0) { + p = pa_memblock_acquire(u->memchunk.memblock); + + if ((frames = snd_pcm_readi(u->pcm_handle, (uint8_t*) p + u->memchunk.index, u->memchunk.length / u->frame_size)) < 0) { + pa_memblock_release(u->memchunk.memblock); + if (frames == -EAGAIN) return; @@ -178,6 +181,7 @@ static void do_read(struct userdata *u) { pa_module_unload_request(u->module); return; } + pa_memblock_release(u->memchunk.memblock); l = frames * u->frame_size; -- cgit