#include <pulse/xmalloc.h>
#include "asyncq.h"
+#include "fdsem.h"
#define ASYNCQ_SIZE 128
/* For debugging purposes we can define _Y to put and extra thread
* yield between each operation. */
+/* #define PROFILE */
+
#ifdef PROFILE
#define _Y pa_thread_yield()
#else
unsigned size;
unsigned read_idx;
unsigned write_idx;
- pa_atomic_t read_waiting; /* a bool */
- pa_atomic_t write_waiting; /* a bool */
- int read_fds[2], write_fds[2];
- pa_atomic_t in_read_fifo, in_write_fifo;
+ pa_fdsem *read_fdsem, *write_fdsem;
};
#define PA_ASYNCQ_CELLS(x) ((pa_atomic_ptr_t*) ((uint8_t*) (x) + PA_ALIGN(sizeof(struct pa_asyncq))))
l = pa_xmalloc0(PA_ALIGN(sizeof(pa_asyncq)) + (sizeof(pa_atomic_ptr_t) * size));
l->size = size;
- pa_atomic_store(&l->read_waiting, 0);
- pa_atomic_store(&l->write_waiting, 0);
- pa_atomic_store(&l->in_read_fifo, 0);
- pa_atomic_store(&l->in_write_fifo, 0);
- if (pipe(l->read_fds) < 0) {
+ if (!(l->read_fdsem = pa_fdsem_new())) {
pa_xfree(l);
return NULL;
}
- if (pipe(l->write_fds) < 0) {
- pa_close(l->read_fds[0]);
- pa_close(l->read_fds[1]);
+ if (!(l->write_fdsem = pa_fdsem_new())) {
+ pa_fdsem_free(l->read_fdsem);
pa_xfree(l);
return NULL;
}
- pa_make_nonblock_fd(l->read_fds[1]);
- pa_make_nonblock_fd(l->write_fds[1]);
-
return l;
}
free_cb(p);
}
- pa_close(l->read_fds[0]);
- pa_close(l->read_fds[1]);
- pa_close(l->write_fds[0]);
- pa_close(l->write_fds[1]);
-
+ pa_fdsem_free(l->read_fdsem);
+ pa_fdsem_free(l->write_fdsem);
pa_xfree(l);
}
if (!pa_atomic_ptr_cmpxchg(&cells[idx], NULL, p)) {
- /* Let's empty the FIFO from old notifications, before we return */
-
- while (pa_atomic_load(&l->in_write_fifo) > 0) {
- ssize_t r;
- int x[20];
-
- if ((r = read(l->write_fds[0], x, sizeof(x))) < 0) {
-
- if (errno == EINTR)
- continue;
-
- return -1;
- }
-
- pa_assert(r > 0);
-
- if (pa_atomic_sub(&l->in_write_fifo, r) <= r)
- break;
-
- }
-
- /* Now let's make sure that we didn't lose any events */
- if (!pa_atomic_ptr_cmpxchg(&cells[idx], NULL, p)) {
-
- if (!wait)
- return -1;
-
- /* Let's wait for changes. */
-
- _Y;
-
- pa_assert_se(pa_atomic_cmpxchg(&l->write_waiting, 0, 1));
-
- for (;;) {
- char x[20];
- ssize_t r;
-
- _Y;
-
- if (pa_atomic_ptr_cmpxchg(&cells[idx], NULL, p))
- break;
-
- _Y;
-
- if ((r = read(l->write_fds[0], x, sizeof(x))) < 0) {
-
- if (errno == EINTR)
- continue;
-
- pa_assert_se(pa_atomic_cmpxchg(&l->write_waiting, 1, 0));
- return -1;
- }
-
- pa_assert(r > 0);
- pa_atomic_sub(&l->in_write_fifo, r);
- }
-
- _Y;
-
- pa_assert_se(pa_atomic_cmpxchg(&l->write_waiting, 1, 0));
- }
+ if (!wait)
+ return -1;
+
+/* pa_log("sleeping on push"); */
+
+ do {
+ pa_fdsem_wait(l->read_fdsem);
+ } while (!pa_atomic_ptr_cmpxchg(&cells[idx], NULL, p));
}
_Y;
l->write_idx++;
- if (pa_atomic_load(&l->read_waiting) > 0) {
- char x = 'x';
- _Y;
- if (write(l->read_fds[1], &x, sizeof(x)) > 0) {
- pa_atomic_inc(&l->in_read_fifo);
-/* pa_log("increasing %p by 1", l); */
- }
- }
+ pa_fdsem_post(l->write_fdsem);
return 0;
}
if (!(ret = pa_atomic_ptr_load(&cells[idx]))) {
-/* pa_log("pop failed wait=%i", wait); */
-
- /* Hmm, nothing, here, so let's drop all queued events. */
- while (pa_atomic_load(&l->in_read_fifo) > 0) {
- ssize_t r;
- int x[20];
-
- if ((r = read(l->read_fds[0], x, sizeof(x))) < 0) {
-
- if (errno == EINTR)
- continue;
-
- return NULL;
- }
-
- pa_assert(r > 0);
-
-/* pa_log("decreasing %p by %i", l, r); */
-
- if (pa_atomic_sub(&l->in_read_fifo, r) <= r)
- break;
- }
-
- /* Now let's make sure that we didn't lose any events */
- if (!(ret = pa_atomic_ptr_load(&cells[idx]))) {
-
- if (!wait)
- return NULL;
-
- /* Let's wait for changes. */
-
- _Y;
-
- pa_assert_se(pa_atomic_cmpxchg(&l->read_waiting, 0, 1));
-
- for (;;) {
- char x[20];
- ssize_t r;
-
- _Y;
-
- if ((ret = pa_atomic_ptr_load(&cells[idx])))
- break;
-
- _Y;
-
- if ((r = read(l->read_fds[0], x, sizeof(x))) < 0) {
-
- if (errno == EINTR)
- continue;
-
- pa_assert_se(pa_atomic_cmpxchg(&l->read_waiting, 1, 0));
- return NULL;
- }
-
-/* pa_log("decreasing %p by %i", l, r); */
-
- pa_assert(r > 0);
- pa_atomic_sub(&l->in_read_fifo, r);
- }
-
- _Y;
-
- pa_assert_se(pa_atomic_cmpxchg(&l->read_waiting, 1, 0));
- }
+ if (!wait)
+ return NULL;
+
+/* pa_log("sleeping on pop"); */
+
+ do {
+ pa_fdsem_wait(l->write_fdsem);
+ } while (!(ret = pa_atomic_ptr_load(&cells[idx])));
}
pa_assert(ret);
- /* Guaranteed if we only have a single reader */
+ /* Guaranteed to succeed if we only have a single reader */
pa_assert_se(pa_atomic_ptr_cmpxchg(&cells[idx], ret, NULL));
_Y;
l->read_idx++;
- if (pa_atomic_load(&l->write_waiting) > 0) {
- char x = 'x';
- _Y;
- if (write(l->write_fds[1], &x, sizeof(x)) >= 0)
- pa_atomic_inc(&l->in_write_fifo);
- }
-
+ pa_fdsem_post(l->read_fdsem);
+
return ret;
}
int pa_asyncq_get_fd(pa_asyncq *q) {
pa_assert(q);
- return q->read_fds[0];
+ return pa_fdsem_get(q->write_fdsem);
}
int pa_asyncq_before_poll(pa_asyncq *l) {
_Y;
idx = reduce(l, l->read_idx);
- if (pa_atomic_ptr_load(&cells[idx]) || pa_atomic_load(&l->in_read_fifo) > 0)
- return -1;
-
- pa_assert_se(pa_atomic_cmpxchg(&l->read_waiting, 0, 1));
+ for (;;) {
+ if (pa_atomic_ptr_load(&cells[idx]))
+ return -1;
- if (pa_atomic_ptr_load(&cells[idx]) || pa_atomic_load(&l->in_read_fifo) > 0) {
- pa_assert_se(pa_atomic_cmpxchg(&l->read_waiting, 1, 0));
- return -1;
+ if (pa_fdsem_before_poll(l->write_fdsem) >= 0)
+ return 0;
}
return 0;
void pa_asyncq_after_poll(pa_asyncq *l) {
pa_assert(l);
- pa_assert_se(pa_atomic_cmpxchg(&l->read_waiting, 1, 0));
+ pa_fdsem_after_poll(l->write_fdsem);
}