/**
* get a connection from the pool
*
* make sure we have at lease <min-conns> for each user
* if we have more, reuse a connect to reauth it to another user
*
* @param pool connection pool to get the connection from
* @param username (optional) name of the auth connection
* @param default_db (unused) unused name of the default-db
*/
network_socket *network_connection_pool_get(network_connection_pool *pool,
GString *username,
GString *UNUSED_PARAM(default_db)) {
network_connection_pool_entry *entry = NULL;
network_socket *sock = NULL;
GQueue *conns = network_connection_pool_get_conns(pool, username, NULL);
/**
* if we know this use, return a authed connection
*/
if (conns) {
entry = g_queue_pop_head(conns);
if (conns->length == 0) {
/**
* all connections are gone, remove it from the hash
*/
g_hash_table_remove(pool->users, username);
}
}
if (!entry) {
#ifdef DEBUG_CONN_POOL
g_debug("%s: (get) no entry for user '%s' -> %p", G_STRLOC, username ? username->str : "", conns);
#endif
return NULL;
}
sock = entry->sock;
network_connection_pool_entry_free(entry, FALSE);
/* remove the idle handler from the socket */
event_del(&(sock->event));
#ifdef DEBUG_CONN_POOL
g_debug("%s: (get) got socket for user '%s' -> %p", G_STRLOC, username ? username->str : "", sock);
#endif
return sock;
}
network_socket *network_connection_pool_get_new(chassis *chas,
network_backend_t *backend, proxy_rw type,
network_connection_pool *pool, const GString *username,
user_pool_config *user_pool_conf,
connection_scaler_pool_statistics *pool_stats) {
guint pool_conn_current_using_sum = 0;
GQueue *conns = NULL;
network_connection_pool_entry *entry = NULL;
GTimeVal now_tv;
guint removed = 0;
network_socket *sock = NULL;
g_assert(chas);
g_assert(backend);
g_assert(type == PROXY_TYPE_WRITE || type == PROXY_TYPE_READ);
g_assert(pool);
g_assert(username);
g_assert(user_pool_conf);
g_assert(pool_stats);
g_assert(backend->pool[type] == pool);
/**
* 取用户连接池
*/
g_mutex_lock(&(pool->connection_pool_mutex));
conns = network_connection_pool_get_conns(pool, username, NULL );
if (conns == NULL ) {
pool_stats->conn_nopool++;
goto NETWORK_CONNECTION_POOL_GET_NEW_EXIT;
}
pool_stats->conn_length = g_queue_get_length(conns);
/**
* 删除空的用户连接池
* 比如最小连接数等于零
*/
if (pool_stats->conn_length == 0) {
pool_stats->conn_zerosize++;
g_hash_table_remove(pool->users, username);
goto NETWORK_CONNECTION_POOL_GET_NEW_EXIT;
}
/**
* 取用户连接池当前连接数，包括未决的和已用的，不包括空闲的(空闲数量应该约等于连接池长度)
*/
pool_conn_current_using_sum = get_conn_using_pending_count(pool, username->str);
/**
* 是否[连接池当前连接]大于[最大连接数]
*/
if (pool_conn_current_using_sum > user_pool_conf->max_connections) {
pool_stats->conn_toomany++;
goto NETWORK_CONNECTION_POOL_GET_NEW_EXIT;
}
g_get_current_time(&now_tv);
/**取出一个连接*/
for (entry = g_queue_pop_head(conns); conns != NULL && entry != NULL ;
entry = g_queue_pop_head(conns)) {
pool_stats->conn_checked++;
/**proxy_get_server_connection_list()这里idle--*/
//update_conn_pool_status_in_state(pool, username->str, POOL_STATUS_STATE_REMOVE_FROM_POOL);
/**
* 检查时间间隔未到，不需要检查，退出(此用户连接池)循环
*/
if (check_pool_entry_connectivity_timeout(entry, &now_tv) == FALSE) {
pool_stats->conn_again++;
break;
}
/**
* 是否断开
*/
if (check_pool_entry_connectivity(entry) == FALSE) {
update_conn_pool_status_in_state(pool, username->str, POOL_STATUS_STATE_REMOVE_FROM_POOL);
garbage_connection_pool_add_entry(pool->garbage_connection_pool,
entry);
pool_stats->conn_disconnected++;
entry = NULL;
pool_conn_current_using_sum = get_conn_using_pending_count(pool, username->str);
continue;
}
/**
* 正常的连接
*/
if (entry != NULL) {
pool_stats->conn_good++;
break;
}
}
NETWORK_CONNECTION_POOL_GET_NEW_EXIT:
g_mutex_unlock(
&(pool->connection_pool_mutex));
removed += pool_stats->conn_disconnected;
if (entry == NULL ) {
#ifdef DEBUG_CONN_POOL
g_debug("%s: (get) no entry for user '%s' -> %p", G_STRLOC, username ? username->str : "", conns);
#endif
return NULL ;
} else {
sock = entry->sock;
network_connection_pool_entry_free(entry, FALSE);
#ifdef DEBUG_CONN_POOL
g_debug("%s: (get) got socket for user '%s' -> %p", G_STRLOC, username ? username->str : "", sock);
#endif
}
return sock;
}
/**
* get a connection from the pool
*
* make sure we have at lease <min-conns> for each user
* if we have more, reuse a connect to reauth it to another user
*
* @param pool connection pool to get the connection from
* @param username (optional) name of the auth connection
* @param default_db (unused) unused name of the default-db
*/
network_socket *network_connection_pool_get(network_connection_pool *pool,
GString *username,
GString *UNUSED_PARAM(default_db), conn_ctl_info *info) {
guint32 cur;
guint len, i;
network_socket *sock = NULL;
network_connection_pool_entry *entry, *found_entry = NULL;
GQueue *conns = network_connection_pool_get_conns(pool, username, NULL);
/**
* if we know this use, return a authed connection
*/
if (conns) {
cur = time(0);
len = g_queue_get_length(conns);
for (i = 0; i < len; i++) {
entry = g_queue_peek_nth(conns, i);
if (entry->key == info->key) {
if (!entry->shared) {
found_entry = entry;
g_queue_pop_nth (conns, i);
break;
}
}
}
if (!found_entry && len > 0) {
entry = g_queue_peek_nth(conns, 0);
found_entry = entry;
g_queue_pop_nth (conns, 0);
g_debug("%s: (get) entry for user '%s' -> %p, cur:%u",
G_STRLOC, username ? username->str : "", entry, cur);
}
if (conns->length == 0) {
/**
* all connections are gone, remove it from the hash
*/
g_hash_table_remove(pool->users, username);
}
}
if (!found_entry) {
g_debug("%s: (get) no entry for user '%s' -> %p", G_STRLOC, username ? username->str : "", conns);
return NULL;
}
sock = found_entry->sock;
g_debug("%s: recv queue length:%d, sock:%p",
G_STRLOC, sock->recv_queue->chunks->length, sock);
network_connection_pool_entry_free(found_entry, FALSE);
/* remove the idle handler from the socket */
event_del(&(sock->event));
g_debug("%s: (get) got socket for user '%s' -> %p", G_STRLOC, username ? username->str : "", sock);
return sock;
}
/**
* get a connection from the pool
* 从连接池头部取出一个连接
*
* make sure we have at lease <min-conns> for each user
* if we have more, reuse a connect to reauth it to another user
*
* @param pool connection pool to get the connection from
* @param username (optional) name of the auth connection
* @param default_db (unused) unused name of the default-db
*/
network_socket *network_connection_pool_get(network_connection_pool *pool,
GString *username,
GString *UNUSED_PARAM(default_db)) {
GQueue *conns = NULL;
network_connection_pool_entry *entry = NULL;
network_socket *sock = NULL;
g_mutex_lock(&(pool->connection_pool_mutex));
conns = network_connection_pool_get_conns(pool, username, NULL);
/**
* if we know this use, return a authed connection
*/
#ifndef CONNECTION_POOL_REGISTER_EVENTS_ENABLED
if (conns) {
entry = g_queue_pop_head(conns);
/**
* 取出一个状态正常的连接，将状态异常的连接放入垃圾回收池
* @todo 这里可以不用检查了？因为已有单独scaler线程定期(若干秒)检查连接状态
*/
while (entry != NULL ) {
if (check_pool_entry_status(entry) == TRUE) {
break;
} else {
garbage_connection_pool_add_entry(pool->garbage_connection_pool, entry);
}
entry = g_queue_pop_head(conns);
}
if (conns->length == 0) {
/**
* all connections are gone, remove it from the hash
*/
g_hash_table_remove(pool->users, username);
}
}
#else
if (conns) {
entry = g_queue_pop_head(conns);
if (conns->length == 0) {
/**
* all connections are gone, remove it from the hash
*/
g_hash_table_remove(pool->users, username);
}
}
#endif
if (!entry) {
#ifdef DEBUG_CONN_POOL
g_debug("%s: (get) no entry for user '%s' -> %p", G_STRLOC, username ? username->str : "", conns);
#endif
g_mutex_unlock(&(pool->connection_pool_mutex));
return NULL;
}
sock = entry->sock;
network_connection_pool_entry_free(entry, FALSE);
/**连接加入连接池时没有注册事件，所以取出时也不需要删除事件*/
// struct event *ev = &(sock->event);
// /* remove the idle handler from the socket */
// if(sock->event.ev_base) {
// g_debug("[%s]: fd: %d, events: %x, callback: %p network_mysqld_pool_con_idle_handle: %p, network_mysqld_cache_con_idle_handle: %p",
// G_STRLOC, event_get_fd(ev), event_get_events(ev),
// event_get_callback(ev),
// network_mysqld_pool_con_idle_handle,
// network_mysqld_cache_con_idle_handle);
// event_del(&(sock->event));
// }
// g_debug("[%s]: fd: %d, events: %x, callback: %p network_mysqld_pool_con_idle_handle: %p, network_mysqld_cache_con_idle_handle: %p",
// G_STRLOC, event_get_fd(ev), event_get_events(ev),
// event_get_callback(ev),
// network_mysqld_pool_con_idle_handle,
// network_mysqld_cache_con_idle_handle);
#ifdef DEBUG_CONN_POOL
g_debug("%s: (get) got socket for user '%s' -> %p", G_STRLOC, username ? username->str : "", sock);
#endif
g_mutex_unlock(&(pool->connection_pool_mutex));
return sock;
}
