optimize the SSL session cache allocations

This commit is contained in:
Igor Sysoev 2007-01-11 17:39:02 +00:00
parent e532b0194c
commit b317945089
2 changed files with 43 additions and 56 deletions

View File

@ -1232,6 +1232,14 @@ ngx_ssl_session_cache_init(ngx_shm_zone_t *shm_zone, void *data)
/*
* The length of the session id is 16 bytes for SSLv2 sessions and
* between 1 and 32 bytes for SSLv3/TLSv1, typically 32 bytes.
* It seems that the typical length of the external ASN1 representation
* of a session is 118 or 119 bytes for SSLv3/TSLv1.
* Thus we allocate separatly an rbtree node, a session id, and an ASN1
* representation and on 32-bit platforms they take accordingly 64, 32, and
* 128 bytes.
*
* OpenSSL's i2d_SSL_SESSION() and d2i_SSL_SESSION are slow,
* so they are outside the code locked by shared pool mutex
*/
@ -1240,7 +1248,7 @@ static int
ngx_ssl_new_session(ngx_ssl_conn_t *ssl_conn, ngx_ssl_session_t *sess)
{
int len;
u_char *p, *id;
u_char *p, *id, *cached_sess;
uint32_t hash;
SSL_CTX *ssl_ctx;
ngx_time_t *tp;
@ -1248,7 +1256,6 @@ ngx_ssl_new_session(ngx_ssl_conn_t *ssl_conn, ngx_ssl_session_t *sess)
ngx_connection_t *c;
ngx_slab_pool_t *shpool;
ngx_ssl_sess_id_t *sess_id;
ngx_ssl_cached_sess_t *cached_sess;
ngx_ssl_session_cache_t *cache;
u_char buf[NGX_SSL_MAX_SESSION_SIZE];
@ -1276,8 +1283,7 @@ ngx_ssl_new_session(ngx_ssl_conn_t *ssl_conn, ngx_ssl_session_t *sess)
/* drop one or two expired sessions */
ngx_ssl_expire_sessions(cache, shpool, 1);
cached_sess = ngx_slab_alloc_locked(shpool,
offsetof(ngx_ssl_cached_sess_t, asn1) + len);
cached_sess = ngx_slab_alloc_locked(shpool, len);
if (cached_sess == NULL) {
@ -1285,8 +1291,7 @@ ngx_ssl_new_session(ngx_ssl_conn_t *ssl_conn, ngx_ssl_session_t *sess)
ngx_ssl_expire_sessions(cache, shpool, 0);
cached_sess = ngx_slab_alloc_locked(shpool,
offsetof(ngx_ssl_cached_sess_t, asn1) + len);
cached_sess = ngx_slab_alloc_locked(shpool, len);
if (cached_sess == NULL) {
id = NULL;
@ -1304,7 +1309,7 @@ ngx_ssl_new_session(ngx_ssl_conn_t *ssl_conn, ngx_ssl_session_t *sess)
goto failed;
}
ngx_memcpy(&cached_sess->asn1[0], buf, len);
ngx_memcpy(cached_sess, buf, len);
ngx_memcpy(id, sess->session_id, sess->session_id_length);
@ -1314,21 +1319,20 @@ ngx_ssl_new_session(ngx_ssl_conn_t *ssl_conn, ngx_ssl_session_t *sess)
"http ssl new session: %08XD:%d:%d",
hash, sess->session_id_length, len);
tp = ngx_timeofday();
sess_id->node.key = hash;
sess_id->node.data = (u_char) sess->session_id_length;
sess_id->id = id;
sess_id->len = len;
sess_id->session = cached_sess;
tp = ngx_timeofday();
sess_id->expire = tp->sec + SSL_CTX_get_timeout(ssl_ctx);
cached_sess->expire = tp->sec + SSL_CTX_get_timeout(ssl_ctx);
cached_sess->sess_id = sess_id;
cached_sess->next = cache->session_cache_head.next;
cached_sess->next->prev = cached_sess;
cached_sess->prev = &cache->session_cache_head;
cache->session_cache_head.next = cached_sess;
sess_id->next = cache->session_cache_head.next;
sess_id->next->prev = sess_id;
sess_id->prev = &cache->session_cache_head;
cache->session_cache_head.next = sess_id;
ngx_rbtree_insert(cache->session_rbtree, &sess_id->node);
@ -1371,7 +1375,6 @@ ngx_ssl_get_cached_session(ngx_ssl_conn_t *ssl_conn, u_char *id, int len,
ngx_rbtree_node_t *node, *sentinel;
ngx_ssl_session_t *sess;
ngx_ssl_sess_id_t *sess_id;
ngx_ssl_cached_sess_t *cached_sess;
ngx_ssl_session_cache_t *cache;
u_char buf[NGX_SSL_MAX_SESSION_SIZE];
@ -1421,12 +1424,10 @@ ngx_ssl_get_cached_session(ngx_ssl_conn_t *ssl_conn, u_char *id, int len,
if (ngx_strncmp(id, sess_id->id, len) == 0) {
cached_sess = sess_id->session;
tp = ngx_timeofday();
if (cached_sess->expire > tp->sec) {
ngx_memcpy(buf, &cached_sess->asn1[0], sess_id->len);
if (sess_id->expire > tp->sec) {
ngx_memcpy(buf, sess_id->session, sess_id->len);
ngx_shmtx_unlock(&shpool->mutex);
@ -1436,12 +1437,12 @@ ngx_ssl_get_cached_session(ngx_ssl_conn_t *ssl_conn, u_char *id, int len,
return sess;
}
cached_sess->next->prev = cached_sess->prev;
cached_sess->prev->next = cached_sess->next;
sess_id->next->prev = sess_id->prev;
sess_id->prev->next = sess_id->next;
ngx_rbtree_delete(cache->session_rbtree, node);
ngx_slab_free_locked(shpool, cached_sess);
ngx_slab_free_locked(shpool, sess_id->session);
ngx_slab_free_locked(shpool, sess_id->id);
ngx_slab_free_locked(shpool, sess_id);
@ -1475,7 +1476,6 @@ ngx_ssl_remove_session(SSL_CTX *ssl, ngx_ssl_session_t *sess)
ngx_slab_pool_t *shpool;
ngx_rbtree_node_t *node, *sentinel;
ngx_ssl_sess_id_t *sess_id;
ngx_ssl_cached_sess_t *cached_sess;
ngx_ssl_session_cache_t *cache;
shm_zone = SSL_CTX_get_ex_data(ssl, ngx_ssl_session_cache_index);
@ -1517,14 +1517,12 @@ ngx_ssl_remove_session(SSL_CTX *ssl, ngx_ssl_session_t *sess)
if (ngx_strncmp(id, sess_id->id, (size_t) len) == 0) {
cached_sess = sess_id->session;
cached_sess->next->prev = cached_sess->prev;
cached_sess->prev->next = cached_sess->next;
sess_id->next->prev = sess_id->prev;
sess_id->prev->next = sess_id->next;
ngx_rbtree_delete(cache->session_rbtree, node);
ngx_slab_free_locked(shpool, cached_sess);
ngx_slab_free_locked(shpool, sess_id->session);
ngx_slab_free_locked(shpool, sess_id->id);
ngx_slab_free_locked(shpool, sess_id);
@ -1549,35 +1547,32 @@ static void
ngx_ssl_expire_sessions(ngx_ssl_session_cache_t *cache,
ngx_slab_pool_t *shpool, ngx_uint_t n)
{
ngx_time_t *tp;
ngx_ssl_sess_id_t *sess_id;
ngx_ssl_cached_sess_t *sess;
ngx_time_t *tp;
ngx_ssl_sess_id_t *sess_id;
tp = ngx_timeofday();
while (n < 3) {
sess = cache->session_cache_tail.prev;
sess_id = cache->session_cache_tail.prev;
if (sess == &cache->session_cache_head) {
if (sess_id == &cache->session_cache_head) {
return;
}
if (n++ != 0 && sess->expire > tp->sec) {
if (n++ != 0 && sess_id->expire > tp->sec) {
break;
}
sess->next->prev = sess->prev;
sess->prev->next = sess->next;
sess_id = sess->sess_id;
sess_id->next->prev = sess_id->prev;
sess_id->prev->next = sess_id->next;
ngx_rbtree_delete(cache->session_rbtree, &sess_id->node);
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, ngx_cycle->log, 0,
"expire session: %08Xi", sess_id->node.key);
ngx_slab_free_locked(shpool, sess);
ngx_slab_free_locked(shpool, sess_id->session);
ngx_slab_free_locked(shpool, sess_id->id);
ngx_slab_free_locked(shpool, sess_id);
}

View File

@ -55,33 +55,25 @@ typedef struct {
#define NGX_SSL_NO_BUILTIN_SCACHE -3
typedef struct ngx_ssl_cached_sess_s ngx_ssl_cached_sess_t;
#define NGX_SSL_MAX_SESSION_SIZE (4096)
typedef struct ngx_ssl_sess_id_s ngx_ssl_sess_id_t;
#define NGX_SSL_MAX_SESSION_SIZE (4096 - offsetof(ngx_ssl_cached_sess_t, asn1))
typedef struct {
struct ngx_ssl_sess_id_s {
ngx_rbtree_node_t node;
u_char *id;
size_t len;
ngx_ssl_cached_sess_t *session;
} ngx_ssl_sess_id_t;
struct ngx_ssl_cached_sess_s {
ngx_ssl_cached_sess_t *prev;
ngx_ssl_cached_sess_t *next;
u_char *session;
ngx_ssl_sess_id_t *prev;
ngx_ssl_sess_id_t *next;
time_t expire;
ngx_ssl_sess_id_t *sess_id;
u_char asn1[1];
};
typedef struct {
ngx_rbtree_t *session_rbtree;
ngx_ssl_cached_sess_t session_cache_head;
ngx_ssl_cached_sess_t session_cache_tail;
ngx_ssl_sess_id_t session_cache_head;
ngx_ssl_sess_id_t session_cache_tail;
} ngx_ssl_session_cache_t;