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lighttpd2/src/main/throttle.c

370 lines
11 KiB

/*
* Implemented with token bucket algorithm.
* On average, the rate of bytes/s never exceeds the specified limit
* but allows small bursts of previously unused bandwidth (max rate*2 for 1 second).
*/
#include <lighttpd/base.h>
static void li_throttle_pool_rearm(liWorker *wrk, liThrottlePool *pool);
liThrottlePool *li_throttle_pool_new(liServer *srv, liThrottlePoolType type, gpointer param, guint rate) {
liThrottlePool *pool;
guint i;
g_mutex_lock(srv->action_mutex);
if (type == LI_THROTTLE_POOL_NAME) {
/* named pool */
GString *name = param;
/* check if we already have a pool with that name */
for (i = 0; i < srv->throttle_pools->len; i++) {
pool = g_array_index(srv->throttle_pools, liThrottlePool*, i);
if (g_string_equal(pool->data.name, name)) {
g_atomic_int_inc(&pool->refcount);
g_mutex_unlock(srv->action_mutex);
g_string_free(name, TRUE);
return pool;
}
}
} else {
/* IP address pool */
liSocketAddress *remote_addr = param;
if (remote_addr->addr->plain.sa_family == AF_INET)
pool = li_radixtree_lookup_exact(srv->throttle_ip_pools, &remote_addr->addr->ipv4.sin_addr.s_addr, 32);
else
pool = li_radixtree_lookup_exact(srv->throttle_ip_pools, &remote_addr->addr->ipv6.sin6_addr.s6_addr, 128);
if (pool) {
g_mutex_unlock(srv->action_mutex);
return pool;
}
}
if (rate == 0) {
g_mutex_unlock(srv->action_mutex);
return NULL;
}
pool = g_slice_new0(liThrottlePool);
pool->type = type;
pool->rate = rate;
pool->last_rearm = THROTTLE_EVTSTAMP_TO_GINT(ev_time());
/*
* We if we are not in LI_SERVER_INIT state, we can initialize the queues directly.
* Otherwise they'll get initialized in the worker prepare callback.
*/
if (g_atomic_int_get(&srv->state) != LI_SERVER_INIT) {
pool->worker_magazine = g_new0(gint, srv->worker_count);
pool->worker_last_rearm = g_new0(gint, srv->worker_count);
pool->worker_num_cons_queued = g_new0(gint, srv->worker_count);
pool->worker_queues = g_new0(GQueue*, srv->worker_count);
for (i = 0; i < srv->worker_count; i++) {
pool->worker_queues[i] = g_queue_new();
pool->worker_last_rearm[i] = pool->last_rearm;
}
}
if (type == LI_THROTTLE_POOL_NAME) {
pool->refcount = 1;
pool->data.name = param;
g_array_append_val(srv->throttle_pools, pool);
} else {
liSocketAddress *remote_addr = param;
pool->data.addr = li_sockaddr_dup(*remote_addr);
if (remote_addr->addr->plain.sa_family == AF_INET)
li_radixtree_insert(srv->throttle_ip_pools, &remote_addr->addr->ipv4.sin_addr.s_addr, 32, pool);
else
li_radixtree_insert(srv->throttle_ip_pools, &remote_addr->addr->ipv6.sin6_addr.s6_addr, 128, pool);
}
g_mutex_unlock(srv->action_mutex);
return pool;
}
void li_throttle_pool_free(liServer *srv, liThrottlePool *pool) {
guint i;
if (!g_atomic_int_dec_and_test(&pool->refcount))
return;
g_mutex_lock(srv->action_mutex);
if (pool->type == LI_THROTTLE_POOL_NAME) {
for (i = 0; i < srv->throttle_pools->len; i++) {
if (pool == g_array_index(srv->throttle_pools, liThrottlePool*, i)) {
g_array_remove_index_fast(srv->throttle_pools, i);
break;
}
}
g_string_free(pool->data.name, TRUE);
} else {
if (pool->data.addr.addr->plain.sa_family == AF_INET)
li_radixtree_remove(srv->throttle_ip_pools, &pool->data.addr.addr->ipv4.sin_addr.s_addr, 32);
else
li_radixtree_remove(srv->throttle_ip_pools, &pool->data.addr.addr->ipv6.sin6_addr.s6_addr, 128);
li_sockaddr_clear(&pool->data.addr);
}
g_mutex_unlock(srv->action_mutex);
if (pool->worker_queues) {
for (i = 0; i < srv->worker_count; i++) {
g_queue_free(pool->worker_queues[i]);
}
g_free(pool->worker_magazine);
g_free(pool->worker_last_rearm);
g_free(pool->worker_num_cons_queued);
g_free(pool->worker_queues);
}
g_slice_free(liThrottlePool, pool);
}
void li_throttle_pool_acquire(liVRequest *vr, liThrottlePool *pool) {
/* already in this pool */
if (vr->throttle.pool.ptr == pool || vr->throttle.ip.ptr == pool)
return;
g_atomic_int_inc(&pool->refcount);
if (pool->type == LI_THROTTLE_POOL_NAME) {
if (vr->throttle.pool.ptr != NULL) {
/* already in a different pool */
li_throttle_pool_release(vr, vr->throttle.pool.ptr);
}
vr->throttle.pool.ptr = pool;
} else {
vr->throttle.ip.ptr = pool;
}
vr->throttled = TRUE;
li_throttle_pool_rearm(vr->wrk, pool);
li_throttle_update(vr, 0, 0);
}
void li_throttle_pool_release(liVRequest *vr, liThrottlePool *pool) {
if (pool->type == LI_THROTTLE_POOL_NAME) {
if (vr->throttle.pool.queue) {
g_atomic_int_add(&pool->worker_num_cons_queued[vr->wrk->ndx], -1);
g_queue_unlink(vr->throttle.pool.queue, &vr->throttle.pool.lnk);
vr->throttle.pool.queue = NULL;
}
vr->throttle.pool.magazine = 0;
vr->throttle.pool.ptr = NULL;
} else {
if (vr->throttle.ip.queue) {
g_atomic_int_add(&pool->worker_num_cons_queued[vr->wrk->ndx], -1);
g_queue_unlink(vr->throttle.ip.queue, &vr->throttle.ip.lnk);
vr->throttle.ip.queue = NULL;
}
vr->throttle.ip.magazine = 0;
vr->throttle.ip.ptr = NULL;
}
li_throttle_pool_free(vr->wrk->srv, pool);
}
static void li_throttle_pool_rearm(liWorker *wrk, liThrottlePool *pool) {
gint time_diff, supply, num_cons, magazine;
guint i;
GQueue *queue;
GList *lnk, *lnk_next;
guint now = THROTTLE_EVTSTAMP_TO_GINT(CUR_TS(wrk));
time_diff = now - pool->worker_last_rearm[wrk->ndx];
/* overflow after 31 days... */
if (G_UNLIKELY(time_diff < 0))
time_diff = 1000;
if (G_LIKELY(time_diff < THROTTLE_GRANULARITY) && G_LIKELY(time_diff > 0))
return;
/* milliseconds since last global rearm */
time_diff = now - g_atomic_int_get(&pool->last_rearm);
if (G_UNLIKELY(time_diff < 0))
time_diff = 1000;
/* check if we have to rearm any magazines */
if (G_UNLIKELY(time_diff >= THROTTLE_GRANULARITY)) {
/* spinlock while we rearm the magazines */
if (g_atomic_int_compare_and_exchange(&pool->rearming, 0, 1)) {
gint worker_num_cons[wrk->srv->worker_count];
/* calculate total cons, take a safe "snapshot" */
num_cons = 0;
for (i = 0; i < wrk->srv->worker_count; i++) {
worker_num_cons[i] = g_atomic_int_get(&pool->worker_num_cons_queued[i]);
num_cons += worker_num_cons[i];
}
if (num_cons) {
/* rearm the worker magazines */
supply = ((pool->rate / 1000) * MIN(time_diff, 1000)) / num_cons;
for (i = 0; i < wrk->srv->worker_count; i++) {
if (worker_num_cons[i] == 0)
continue;
g_atomic_int_add(&pool->worker_magazine[i], supply * worker_num_cons[i]);
}
}
g_atomic_int_set(&pool->last_rearm, now);
g_atomic_int_set(&pool->rearming, 0);
} else {
/* wait for pool rearm to finish */
while (g_atomic_int_get(&pool->rearming) == 1) { }
}
}
/* select current queue */
queue = pool->worker_queues[wrk->ndx];
if (queue->length) {
g_atomic_int_set(&pool->worker_num_cons_queued[wrk->ndx], 0);
magazine = g_atomic_int_get(&pool->worker_magazine[wrk->ndx]);
g_atomic_int_add(&pool->worker_magazine[wrk->ndx], -magazine);
supply = magazine / queue->length;
/* rearm connections */
for (lnk = g_queue_peek_head_link(queue); lnk != NULL; lnk = lnk_next) {
if (pool->type == LI_THROTTLE_POOL_NAME) {
((liVRequest*)lnk->data)->throttle.pool.magazine += supply;
((liVRequest*)lnk->data)->throttle.pool.queue = NULL;
} else {
((liVRequest*)lnk->data)->throttle.ip.magazine += supply;
((liVRequest*)lnk->data)->throttle.ip.queue = NULL;
}
lnk_next = lnk->next;
lnk->next = NULL;
lnk->prev = NULL;
}
/* clear current connection queue */
g_queue_init(queue);
}
pool->worker_last_rearm[wrk->ndx] = now;
}
void li_throttle_reset(liVRequest *vr) {
if (!vr->throttled)
return;
/* remove from throttle queue */
li_waitqueue_remove(&vr->wrk->throttle_queue, &vr->throttle.wqueue_elem);
if (vr->throttle.pool.ptr)
li_throttle_pool_release(vr, vr->throttle.pool.ptr);
if (vr->throttle.ip.ptr)
li_throttle_pool_release(vr, vr->throttle.ip.ptr);
vr->throttle.pool.magazine = 0;
vr->throttle.ip.magazine = 0;
vr->throttle.con.rate = 0;
vr->throttle.magazine = 0;
vr->throttled = FALSE;
}
void li_throttle_cb(liWaitQueue *wq, gpointer data) {
liWaitQueueElem *wqe;
liVRequest *vr;
liWorker *wrk;
gint supply;
wrk = data;
while (NULL != (wqe = li_waitqueue_pop(wq))) {
vr = wqe->data;
if (vr->throttle.pool.ptr) {
/* throttled by pool */
li_throttle_pool_rearm(wrk, vr->throttle.pool.ptr);
if (vr->throttle.ip.ptr) {
/* throttled by pool+IP */
li_throttle_pool_rearm(wrk, vr->throttle.ip.ptr);
supply = MIN(vr->throttle.pool.magazine, vr->throttle.ip.magazine);
if (vr->throttle.con.rate) {
/* throttled by pool+IP+con */
supply = MIN(supply, vr->throttle.con.rate / 1000 * THROTTLE_GRANULARITY);
}
vr->throttle.pool.magazine -= supply;
vr->throttle.ip.magazine -= supply;
vr->throttle.magazine += supply;
} else if (vr->throttle.con.rate) {
/* throttled by pool+con */
supply = MIN(vr->throttle.pool.magazine, vr->throttle.con.rate / 1000 * THROTTLE_GRANULARITY);
vr->throttle.magazine += supply;
vr->throttle.pool.magazine -= supply;
} else {
vr->throttle.magazine += vr->throttle.pool.magazine;
vr->throttle.pool.magazine = 0;
}
} else if (vr->throttle.ip.ptr) {
/* throttled by IP */
li_throttle_pool_rearm(wrk, vr->throttle.ip.ptr);
if (vr->throttle.con.rate) {
/* throttled by IP+con */
supply = MIN(vr->throttle.ip.magazine, vr->throttle.con.rate / 1000 * THROTTLE_GRANULARITY);
vr->throttle.magazine += supply;
vr->throttle.ip.magazine -= supply;
} else {
vr->throttle.magazine += vr->throttle.ip.magazine;
vr->throttle.ip.magazine = 0;
}
} else {
/* throttled by connection */
if (vr->throttle.magazine <= vr->throttle.con.rate)
vr->throttle.magazine += vr->throttle.con.rate / 1000 * THROTTLE_GRANULARITY;
}
vr->coninfo->callbacks->handle_check_io(vr);
}
li_waitqueue_update(wq);
}
void li_throttle_update(liVRequest *vr, goffset transferred, goffset write_max) {
vr->throttle.magazine -= transferred;
if (vr->throttle.magazine <= 0) {
li_waitqueue_push(&vr->wrk->throttle_queue, &vr->throttle.wqueue_elem);
}
/* queue in pool if necessary */
if (vr->throttle.pool.ptr && vr->throttle.pool.magazine <= write_max && !vr->throttle.pool.queue) {
liThrottlePool *pool = vr->throttle.pool.ptr;
vr->throttle.pool.queue = pool->worker_queues[vr->wrk->ndx];
g_queue_push_tail_link(vr->throttle.pool.queue, &vr->throttle.pool.lnk);
g_atomic_int_inc(&pool->worker_num_cons_queued[vr->wrk->ndx]);
}
/* queue in IP pool if necessary */
if (vr->throttle.ip.ptr && vr->throttle.ip.magazine <= write_max && !vr->throttle.ip.queue) {
liThrottlePool *pool = vr->throttle.ip.ptr;
vr->throttle.ip.queue = pool->worker_queues[vr->wrk->ndx];
g_queue_push_tail_link(vr->throttle.ip.queue, &vr->throttle.ip.lnk);
g_atomic_int_inc(&pool->worker_num_cons_queued[vr->wrk->ndx]);
}
}