int ringbuf_push(const char *value, size_t len) {
static pid_t pid = 0;
if (unlikely(len > shm->size))
return -1;
if (unlikely(pid == 0))
pid = getpid();
shmtx_lock(&mutex_w, pid);
uint32_t index_w = shm->index_w;
uint32_t next = Next_Slot(index_w, shm->max);
if (next == shm->index_r) {
shmtx_unlock(&mutex_w, pid);
return Cache_Full;
}
memcpy(shm->datas + index_w * shm->size, value, len);
atomic_cmp_set(&shm->index_w, index_w, next);
if (!shmtx_unlock(&mutex_w, pid)) {
#ifdef RB_DEBUG
printf("push lock exception! %lu\n", *mutex_w.lock);
#endif
}
return 0;
}
int ringbuf_pop(char *value) {
static pid_t pid = 0;
if (unlikely(pid == 0))
pid = getpid();
shmtx_lock(&mutex_r, pid);
uint32_t index_r = shm->index_r;
if (shm->index_w == index_r) {
shmtx_unlock(&mutex_r, pid);
return No_Data;
}
uint32_t next = Next_Slot(index_r, shm->max);
memcpy(value, shm->datas + index_r * shm->size, shm->size);
atomic_cmp_set(&shm->index_r, index_r, next);
if (!shmtx_unlock(&mutex_r, pid)) {
#ifdef RB_DEBUG
printf("pop lock exception! %lu \n", *mutex_r.lock);
#endif
}
return 0;
}
void spinlock_lock(atomic_t* locker)
{
int i, count = 0, n = 0;
for (;;++count)
{
if (*locker == 0 && atomic_cmp_set(locker, 0, 1)) { return; }
if (sys_cpus > 1)
{
for (n = 1; n < 16; n <<= 1)
{
for (i = 0; i < n; i++)
{
pause();
}
if (*locker == 0 && atomic_cmp_set(locker, 0, 1)) { return; }
}
}
sched_yield();
}
}
bool spinlock_trylock(atomic_t* locker)
{
return (*(locker) == 0 && atomic_cmp_set(locker, 0, 1));
}