pa_shmasyncq *pa_shmasyncq_new(unsigned n_elements, size_t element_size, void *data, int fd[2]) {
pa_shmasyncq *l;
pa_assert(n_elements > 0);
pa_assert(is_power_of_two(n_elements));
pa_assert(element_size > 0);
pa_assert(data);
pa_assert(fd);
l = pa_xnew(pa_shmasyncq, 1);
l->data = data;
memset(data, 0, PA_SHMASYNCQ_SIZE(n_elements, element_size));
l->data->n_elements = n_elements;
l->data->element_size = element_size;
if (!(l->read_fdsem = pa_fdsem_new_shm(&d->read_fdsem_data))) {
pa_xfree(l);
return NULL;
}
fd[0] = pa_fdsem_get(l->read_fdsem);
if (!(l->write_fdsem = pa_fdsem_new(&d->write_fdsem_data, &fd[1]))) {
pa_fdsem_free(l->read_fdsem);
pa_xfree(l);
return NULL;
}
return l;
}
pa_srbchannel* pa_srbchannel_new(pa_mainloop_api *m, pa_mempool *p) {
int capacity;
int readfd;
struct srbheader *srh;
pa_srbchannel* sr = pa_xmalloc0(sizeof(pa_srbchannel));
sr->mainloop = m;
sr->memblock = pa_memblock_new_pool(p, -1);
if (!sr->memblock)
goto fail;
srh = pa_memblock_acquire(sr->memblock);
pa_zero(*srh);
sr->rb_read.memory = (uint8_t*) srh + PA_ALIGN(sizeof(*srh));
srh->readbuf_offset = sr->rb_read.memory - (uint8_t*) srh;
capacity = (pa_memblock_get_length(sr->memblock) - srh->readbuf_offset) / 2;
sr->rb_write.memory = PA_ALIGN_PTR(sr->rb_read.memory + capacity);
srh->writebuf_offset = sr->rb_write.memory - (uint8_t*) srh;
capacity = PA_MIN(capacity, srh->writebuf_offset - srh->readbuf_offset);
pa_log_debug("SHM block is %d bytes, ringbuffer capacity is 2 * %d bytes",
(int) pa_memblock_get_length(sr->memblock), capacity);
srh->capacity = sr->rb_read.capacity = sr->rb_write.capacity = capacity;
sr->rb_read.count = &srh->read_count;
sr->rb_write.count = &srh->write_count;
sr->sem_read = pa_fdsem_new_shm(&srh->read_semdata);
if (!sr->sem_read)
goto fail;
sr->sem_write = pa_fdsem_new_shm(&srh->write_semdata);
if (!sr->sem_write)
goto fail;
readfd = pa_fdsem_get(sr->sem_read);
#ifdef DEBUG_SRBCHANNEL
pa_log("Enabling io event on fd %d", readfd);
#endif
sr->read_event = m->io_new(m, readfd, PA_IO_EVENT_INPUT, semread_cb, sr);
m->io_enable(sr->read_event, PA_IO_EVENT_INPUT);
return sr;
fail:
pa_srbchannel_free(sr);
return NULL;
}
int pa_shmasyncq_get_fd(pa_shmasyncq *q) {
pa_assert(q);
return pa_fdsem_get(q->write_fdsem);
}
int pa_asyncq_write_fd(pa_asyncq *q) {
pa_assert(q);
return pa_fdsem_get(q->read_fdsem);
}
void pa_srbchannel_export(pa_srbchannel *sr, pa_srbchannel_template *t) {
t->memblock = sr->memblock;
t->readfd = pa_fdsem_get(sr->sem_read);
t->writefd = pa_fdsem_get(sr->sem_write);
}
