port asyncq to make use of new fdsem object

git-svn-id: file:///home/lennart/svn/public/pulseaudio/branches/lennart@1538 fefdeb5f-60dc-0310-8127-8f9354f1896f
This commit is contained in:
Lennart Poettering 2007-07-26 13:15:05 +00:00
parent 6ad165c686
commit bc3693261f

View file

@ -36,12 +36,15 @@
#include <pulse/xmalloc.h> #include <pulse/xmalloc.h>
#include "asyncq.h" #include "asyncq.h"
#include "fdsem.h"
#define ASYNCQ_SIZE 128 #define ASYNCQ_SIZE 128
/* For debugging purposes we can define _Y to put and extra thread /* For debugging purposes we can define _Y to put and extra thread
* yield between each operation. */ * yield between each operation. */
/* #define PROFILE */
#ifdef PROFILE #ifdef PROFILE
#define _Y pa_thread_yield() #define _Y pa_thread_yield()
#else #else
@ -52,10 +55,7 @@ struct pa_asyncq {
unsigned size; unsigned size;
unsigned read_idx; unsigned read_idx;
unsigned write_idx; unsigned write_idx;
pa_atomic_t read_waiting; /* a bool */ pa_fdsem *read_fdsem, *write_fdsem;
pa_atomic_t write_waiting; /* a bool */
int read_fds[2], write_fds[2];
pa_atomic_t in_read_fifo, in_write_fifo;
}; };
#define PA_ASYNCQ_CELLS(x) ((pa_atomic_ptr_t*) ((uint8_t*) (x) + PA_ALIGN(sizeof(struct pa_asyncq)))) #define PA_ASYNCQ_CELLS(x) ((pa_atomic_ptr_t*) ((uint8_t*) (x) + PA_ALIGN(sizeof(struct pa_asyncq))))
@ -79,26 +79,18 @@ pa_asyncq *pa_asyncq_new(unsigned size) {
l = pa_xmalloc0(PA_ALIGN(sizeof(pa_asyncq)) + (sizeof(pa_atomic_ptr_t) * size)); l = pa_xmalloc0(PA_ALIGN(sizeof(pa_asyncq)) + (sizeof(pa_atomic_ptr_t) * size));
l->size = 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); pa_xfree(l);
return NULL; return NULL;
} }
if (pipe(l->write_fds) < 0) { if (!(l->write_fdsem = pa_fdsem_new())) {
pa_close(l->read_fds[0]); pa_fdsem_free(l->read_fdsem);
pa_close(l->read_fds[1]);
pa_xfree(l); pa_xfree(l);
return NULL; return NULL;
} }
pa_make_nonblock_fd(l->read_fds[1]);
pa_make_nonblock_fd(l->write_fds[1]);
return l; return l;
} }
@ -112,11 +104,8 @@ void pa_asyncq_free(pa_asyncq *l, pa_free_cb_t free_cb) {
free_cb(p); free_cb(p);
} }
pa_close(l->read_fds[0]); pa_fdsem_free(l->read_fdsem);
pa_close(l->read_fds[1]); pa_fdsem_free(l->write_fdsem);
pa_close(l->write_fds[0]);
pa_close(l->write_fds[1]);
pa_xfree(l); pa_xfree(l);
} }
@ -132,82 +121,22 @@ int pa_asyncq_push(pa_asyncq*l, void *p, int wait) {
_Y; _Y;
idx = reduce(l, l->write_idx); idx = reduce(l, l->write_idx);
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 (!pa_atomic_ptr_cmpxchg(&cells[idx], NULL, p)) {
if (!wait) if (!wait)
return -1; return -1;
/* Let's wait for changes. */ /* pa_log("sleeping on push"); */
_Y; do {
pa_fdsem_wait(l->read_fdsem);
pa_assert_se(pa_atomic_cmpxchg(&l->write_waiting, 0, 1)); } while (!pa_atomic_ptr_cmpxchg(&cells[idx], NULL, p));
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));
}
} }
_Y; _Y;
l->write_idx++; l->write_idx++;
if (pa_atomic_load(&l->read_waiting) > 0) { pa_fdsem_post(l->write_fdsem);
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); */
}
}
return 0; return 0;
} }
@ -226,87 +155,25 @@ void* pa_asyncq_pop(pa_asyncq*l, int wait) {
if (!(ret = pa_atomic_ptr_load(&cells[idx]))) { 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) if (!wait)
return NULL; return NULL;
/* Let's wait for changes. */ /* pa_log("sleeping on pop"); */
_Y; do {
pa_fdsem_wait(l->write_fdsem);
pa_assert_se(pa_atomic_cmpxchg(&l->read_waiting, 0, 1)); } while (!(ret = pa_atomic_ptr_load(&cells[idx])));
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));
}
} }
pa_assert(ret); 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)); pa_assert_se(pa_atomic_ptr_cmpxchg(&cells[idx], ret, NULL));
_Y; _Y;
l->read_idx++; l->read_idx++;
if (pa_atomic_load(&l->write_waiting) > 0) { pa_fdsem_post(l->read_fdsem);
char x = 'x';
_Y;
if (write(l->write_fds[1], &x, sizeof(x)) >= 0)
pa_atomic_inc(&l->in_write_fifo);
}
return ret; return ret;
} }
@ -314,7 +181,7 @@ void* pa_asyncq_pop(pa_asyncq*l, int wait) {
int pa_asyncq_get_fd(pa_asyncq *q) { int pa_asyncq_get_fd(pa_asyncq *q) {
pa_assert(q); pa_assert(q);
return q->read_fds[0]; return pa_fdsem_get(q->write_fdsem);
} }
int pa_asyncq_before_poll(pa_asyncq *l) { int pa_asyncq_before_poll(pa_asyncq *l) {
@ -328,14 +195,12 @@ int pa_asyncq_before_poll(pa_asyncq *l) {
_Y; _Y;
idx = reduce(l, l->read_idx); idx = reduce(l, l->read_idx);
if (pa_atomic_ptr_load(&cells[idx]) || pa_atomic_load(&l->in_read_fifo) > 0) for (;;) {
if (pa_atomic_ptr_load(&cells[idx]))
return -1; return -1;
pa_assert_se(pa_atomic_cmpxchg(&l->read_waiting, 0, 1)); if (pa_fdsem_before_poll(l->write_fdsem) >= 0)
return 0;
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;
} }
return 0; return 0;
@ -344,5 +209,5 @@ int pa_asyncq_before_poll(pa_asyncq *l) {
void pa_asyncq_after_poll(pa_asyncq *l) { void pa_asyncq_after_poll(pa_asyncq *l) {
pa_assert(l); pa_assert(l);
pa_assert_se(pa_atomic_cmpxchg(&l->read_waiting, 1, 0)); pa_fdsem_after_poll(l->write_fdsem);
} }