char *generate_name(char *buf, const char *radix,
struct name_generator *ngen)
{
int len = ngen->length - 1, tag;
if (radix && *radix) {
strncpy(buf, radix, len);
buf[len] = '\0';
} else {
tag = atomic_add_fetch(&ngen->serial, 1);
snprintf(buf, len, "%s@%d", ngen->radix, tag);
}
return buf;
}
void mp_retain(mempool_t *mp)
{
atomic_add_fetch(&mp->refcnt, 1);
}
int mp_create(mempool_priv_t *mp_priv, const char *name, unsigned int entries,
unsigned int buckets)
{
int fd, i, mask = entries - 1;
mempool_t *mp;
int size = sizeof(mempool_t)
+ (sizeof(mp_ring_t) + sizeof(void *) * entries) * buckets
+ sizeof(mp_buf_t) * entries;
if (buckets < 2 || buckets > MEM_POOL_MAX_BUCKETS) {
fprintf(stderr, "number of buckets must be greater than 1 and "
"less than %d\n", MEM_POOL_MAX_BUCKETS);
return -1;
}
if (!POWEROF2(entries)) {
fprintf(stderr, "number of entries must be power of 2\n");
return -1;
}
/* open shared memory */
if ((fd = shm_open(name, O_CREAT|O_RDWR|O_TRUNC, S_IRUSR|S_IWUSR)) < 0)
return -1;
if ((ftruncate(fd, size)) < 0) {
shm_unlink(name);
close(fd);
}
mp = mmap(NULL, size, PROT_WRITE | PROT_READ, MAP_SHARED, fd, 0);
if ((long)mp == -1) {
shm_unlink(name);
close(fd);
}
atomic_add_fetch(&mp->refcnt, 1);
mp->size = size;
mp->entries = entries;
strncpy(mp->name, name, MEM_POOL_MAX_NAME);
mp->buckets = buckets;
memset(mp_priv->fds, -1, sizeof(int) * MEM_POOL_MAX_FDS);
mp_priv->mp = mp;
mp_priv->bucket[0] = (mp_ring_t *)((char *)mp + sizeof(mempool_t));
mp_priv->bucket[0]->mask = mask;
for (i = 1; i < buckets; i++) {
mp_ring_t *ring = (mp_ring_t *)((char *)mp_priv->bucket[i-1]
+ sizeof(mp_ring_t)
+ sizeof(void *) * entries);
ring->mask = mask;
mp_priv->bucket[i] = ring;
}
mp_priv->data = (mp_buf_t *)((char *)mp_priv->bucket[buckets-1]
+ sizeof(mp_ring_t) + sizeof(void *) * entries);
if ((uintptr_t)mp_priv->data & __cache_line_mask) {
fprintf(stderr, "mp_priv->data not cache aligned\n");
goto error;
}
mp_priv->entries = entries;
/* fill up the 1st ring */
for (i = 0; i < entries - 1; i++) {
mp_buf_priv_t buf = {
.offset = i,
#ifndef NDEBUG
.buf = &mp_priv->data[i],
#endif
};
#ifndef NDEBUG
mp_priv->data[i].owner = -1;
if ((long)buf.buf & __cache_line_mask) {
fprintf(stderr, "buf not cache aligned\n");
goto error;
}
#endif
if (mp_put(mp_priv, 0, &buf) < 0)
goto error;
}
close(fd);
return 0;
error:
munmap(mp, size);
shm_unlink(name);
close(fd);
return -1;
}
int mp_create_notifs(mempool_priv_t *mp_priv, unsigned notifications)
{
int i;
if (notifications > MEM_POOL_MAX_FDS) {
fprintf(stderr, "number of notifications cannot exceed %d\n",
MEM_POOL_MAX_FDS);
return -1;
}
for (i = 0; i < notifications; i++) {
int efd;
if (mp_priv->fds[i] != -1)
return -1;
efd = eventfd(0, 0);
if (efd < 0)
return -1;
mp_priv->fds[i] = efd;
}
return 0;
}
