示例#1
0
static void erase_ref(h2o_cache_t *cache, khiter_t iter, int reuse)
{
    h2o_cache_ref_t *ref = kh_key(cache->table, iter);

    if (!reuse)
        kh_del(cache, cache->table, iter);
    h2o_linklist_unlink(&ref->_lru_link);
    h2o_linklist_unlink(&ref->_age_link);
    cache->size -= ref->value.len;

    h2o_cache_release(cache, ref);
}
示例#2
0
void h2o_multithread_send_message(h2o_multithread_receiver_t *receiver, h2o_multithread_message_t *message)
{
    int do_send = 0;

    pthread_mutex_lock(&receiver->queue->mutex);
    if (message != NULL) {
        assert(!h2o_linklist_is_linked(&message->link));
        if (h2o_linklist_is_empty(&receiver->_messages)) {
            h2o_linklist_unlink(&receiver->_link);
            h2o_linklist_insert(&receiver->queue->receivers.active, &receiver->_link);
            do_send = 1;
        }
        h2o_linklist_insert(&receiver->_messages, &message->link);
    } else {
        if (h2o_linklist_is_empty(&receiver->_messages))
            do_send = 1;
    }
    pthread_mutex_unlock(&receiver->queue->mutex);

    if (do_send) {
#if H2O_USE_LIBUV
        uv_async_send(&receiver->queue->async);
#else
        while (write(receiver->queue->async.write, "", 1) == -1 && errno == EINTR)
            ;
#endif
    }
}
示例#3
0
文件: timeout.c 项目: topcpporg/h2
void h2o_timeout_unlink(h2o_timeout_entry_t *entry)
{
    if (h2o_linklist_is_linked(&entry->_link)) {
        h2o_linklist_unlink(&entry->_link);
        entry->registered_at = 0;
    }
}
示例#4
0
static h2o_memcached_req_t *pop_inflight(struct st_h2o_memcached_conn_t *conn, uint32_t serial)
{
    h2o_memcached_req_t *req;

    pthread_mutex_lock(&conn->mutex);

    if (conn->yrmcds.text_mode) {
        /* in text mode, responses are returned in order (and we may receive responses for commands other than GET) */
        if (!h2o_linklist_is_empty(&conn->inflight)) {
            req = H2O_STRUCT_FROM_MEMBER(h2o_memcached_req_t, inflight, conn->inflight.next);
            assert(req->type == REQ_TYPE_GET);
            if (req->data.get.serial == serial)
                goto Found;
        }
    } else {
        /* in binary mode, responses are received out-of-order (and we would only recieve responses for GET) */
        h2o_linklist_t *node;
        for (node = conn->inflight.next; node != &conn->inflight; node = node->next) {
            req = H2O_STRUCT_FROM_MEMBER(h2o_memcached_req_t, inflight, node);
            assert(req->type == REQ_TYPE_GET);
            if (req->data.get.serial == serial)
                goto Found;
        }
    }

    /* not found */
    pthread_mutex_unlock(&conn->mutex);
    return NULL;

Found:
    h2o_linklist_unlink(&req->inflight);
    pthread_mutex_unlock(&conn->mutex);
    return req;
}
示例#5
0
void h2o_multithread_unregister_receiver(h2o_multithread_queue_t *queue, h2o_multithread_receiver_t *receiver)
{
    assert(queue == receiver->queue);
    assert(h2o_linklist_is_empty(&receiver->_messages));
    pthread_mutex_lock(&queue->mutex);
    h2o_linklist_unlink(&receiver->_link);
    pthread_mutex_unlock(&queue->mutex);
}
示例#6
0
文件: http1.c 项目: dstufft/h2o
static void close_connection(struct st_h2o_http1_conn_t *conn, int close_socket)
{
    h2o_timeout_unlink(&conn->_timeout_entry);
    h2o_dispose_request(&conn->req);
    if (conn->sock != NULL && close_socket)
        h2o_socket_close(conn->sock);
    h2o_linklist_unlink(&conn->_conns);
    free(conn);
}
示例#7
0
void h2o_configurator__dispose_configurators(h2o_globalconf_t *conf)
{
    while (!h2o_linklist_is_empty(&conf->configurators)) {
        h2o_configurator_t *c = H2O_STRUCT_FROM_MEMBER(h2o_configurator_t, _link, conf->configurators.next);
        h2o_linklist_unlink(&c->_link);
        if (c->dispose != NULL)
            c->dispose(c);
        destroy_configurator(c);
    }
}
示例#8
0
static void *writer_main(void *_conn)
{
    struct st_h2o_memcached_conn_t *conn = _conn;
    yrmcds_error err;

    pthread_mutex_lock(&conn->ctx->mutex);

    while (!__sync_add_and_fetch(&conn->writer_exit_requested, 0)) {
        while (!h2o_linklist_is_empty(&conn->ctx->pending)) {
            h2o_memcached_req_t *req = H2O_STRUCT_FROM_MEMBER(h2o_memcached_req_t, pending, conn->ctx->pending.next);
            h2o_linklist_unlink(&req->pending);
            pthread_mutex_unlock(&conn->ctx->mutex);

            switch (req->type) {
            case REQ_TYPE_GET:
                pthread_mutex_lock(&conn->mutex);
                h2o_linklist_insert(&conn->inflight, &req->inflight);
                pthread_mutex_unlock(&conn->mutex);
                if ((err = yrmcds_get(&conn->yrmcds, req->key.base, req->key.len, 0, &req->data.get.serial)) != YRMCDS_OK)
                    goto Error;
                break;
            case REQ_TYPE_SET:
                err = yrmcds_set(&conn->yrmcds, req->key.base, req->key.len, req->data.set.value.base, req->data.set.value.len, 0,
                                 req->data.set.expiration, 0, !conn->yrmcds.text_mode, NULL);
                discard_req(req);
                if (err != YRMCDS_OK)
                    goto Error;
                break;
            case REQ_TYPE_DELETE:
                err = yrmcds_remove(&conn->yrmcds, req->key.base, req->key.len, !conn->yrmcds.text_mode, NULL);
                discard_req(req);
                if (err != YRMCDS_OK)
                    goto Error;
                break;
            default:
                fprintf(stderr, "[lib/common/memcached.c] unknown type:%d\n", (int)req->type);
                err = YRMCDS_NOT_IMPLEMENTED;
                goto Error;
            }

            pthread_mutex_lock(&conn->ctx->mutex);
        }
        pthread_cond_wait(&conn->ctx->cond, &conn->ctx->mutex);
    }

    pthread_mutex_unlock(&conn->ctx->mutex);
    return NULL;

Error:
    fprintf(stderr, "[lib/common/memcached.c] failed to send request; %s\n", yrmcds_strerror(err));
    /* doc says the call can be used to interrupt yrmcds_recv */
    yrmcds_shutdown(&conn->yrmcds);

    return NULL;
}
示例#9
0
文件: filecache.c 项目: IvwsIgeMq/h2o
static inline void release_from_cache(h2o_filecache_t *cache, khiter_t iter)
{
    const char *path = kh_key(cache->hash, iter);
    h2o_filecache_ref_t *ref = H2O_STRUCT_FROM_MEMBER(h2o_filecache_ref_t, _path, path);

    /* detach from list */
    kh_del(opencache_set, cache->hash, iter);
    h2o_linklist_unlink(&ref->_lru);

    /* and close */
    h2o_filecache_close_file(ref);
}
示例#10
0
文件: connection.c 项目: tidatida/h2o
static void run_pending_requests(h2o_http2_conn_t *conn)
{
    while (!h2o_linklist_is_empty(&conn->_pending_reqs) && can_run_requests(conn)) {
        /* fetch and detach a pending stream */
        h2o_http2_stream_t *stream = H2O_STRUCT_FROM_MEMBER(h2o_http2_stream_t, _refs.link, conn->_pending_reqs.next);
        h2o_linklist_unlink(&stream->_refs.link);
        /* handle it */
        h2o_http2_stream_set_state(conn, stream, H2O_HTTP2_STREAM_STATE_SEND_HEADERS);
        if (!h2o_http2_stream_is_push(stream->stream_id) && conn->pull_stream_ids.max_processed < stream->stream_id)
            conn->pull_stream_ids.max_processed = stream->stream_id;
        h2o_process_request(&stream->req);
    }
}
示例#11
0
文件: config.c 项目: Gwill/h2o
void h2o_config_dispose(h2o_global_configuration_t *config)
{
    while (! h2o_linklist_is_empty(&config->virtual_hosts)) {
        h2o_host_configuration_t *host_config = H2O_STRUCT_FROM_MEMBER(h2o_host_configuration_t, _link, config->virtual_hosts.next);
        h2o_linklist_unlink(&host_config->_link);
        dispose_host_config(host_config);
        free(host_config);
    }
    dispose_host_config(&config->default_host);
    DESTROY_LIST(h2o_configurator_t, config->global_configurators);
    DESTROY_LIST(h2o_configurator_t, config->host_configurators);

}
示例#12
0
void h2o_socketpool_connect(h2o_socketpool_connect_request_t **_req, h2o_socketpool_t *pool, h2o_loop_t *loop,
                            h2o_multithread_receiver_t *getaddr_receiver, h2o_socketpool_connect_cb cb, void *data)
{
    struct pool_entry_t *entry = NULL;

    if (_req != NULL)
        *_req = NULL;

    /* fetch an entry */
    pthread_mutex_lock(&pool->_shared.mutex);
    destroy_expired(pool);
    if (!h2o_linklist_is_empty(&pool->_shared.sockets)) {
        entry = H2O_STRUCT_FROM_MEMBER(struct pool_entry_t, link, pool->_shared.sockets.next);
        h2o_linklist_unlink(&entry->link);
    }
示例#13
0
文件: timeout.c 项目: topcpporg/h2
void h2o_timeout_run(h2o_loop_t *loop, h2o_timeout_t *timeout, uint64_t now)
{
    uint64_t max_registered_at = now - timeout->timeout;

    while (!h2o_linklist_is_empty(&timeout->_entries)) {
        h2o_timeout_entry_t *entry = H2O_STRUCT_FROM_MEMBER(h2o_timeout_entry_t, _link, timeout->_entries.next);
        if (entry->registered_at > max_registered_at) {
            break;
        }
        h2o_linklist_unlink(&entry->_link);
        entry->registered_at = 0;
        entry->cb(entry);
        h2o_timeout__do_post_callback(loop);
    }
}
示例#14
0
文件: hostinfo.c 项目: topcpporg/h2
void h2o_hostinfo_getaddr_receiver(h2o_multithread_receiver_t *receiver, h2o_linklist_t *messages)
{
    while (!h2o_linklist_is_empty(messages)) {
        h2o_hostinfo_getaddr_req_t *req = H2O_STRUCT_FROM_MEMBER(h2o_hostinfo_getaddr_req_t, _out.message.link, messages->next);
        h2o_linklist_unlink(&req->_out.message.link);
        h2o_hostinfo_getaddr_cb cb = req->_cb;
        if (cb != NULL) {
            req->_cb = NULL;
            cb(req, req->_out.errstr, req->_out.ai, req->cbdata);
        }
        if (req->_out.ai != NULL)
            freeaddrinfo(req->_out.ai);
        free(req);
    }
}
示例#15
0
文件: memcached.c 项目: Handy2015/h2o
void h2o_memcached_cancel_get(h2o_memcached_context_t *ctx, h2o_memcached_req_t *req)
{
    int do_free = 0;

    pthread_mutex_lock(&ctx->mutex);
    req->data.get.cb = NULL;
    if (h2o_linklist_is_linked(&req->pending)) {
        h2o_linklist_unlink(&req->pending);
        do_free = 1;
    }
    pthread_mutex_unlock(&ctx->mutex);

    if (do_free)
        free_req(req);
}
示例#16
0
static void run_pending_requests(h2o_http2_conn_t *conn)
{
    conn->_is_dispatching_pending_reqs = 1;

    while (!h2o_linklist_is_empty(&conn->_pending_reqs) &&
           conn->num_streams.responding < conn->super.ctx->globalconf->http2.max_concurrent_requests_per_connection) {
        /* fetch and detach a pending stream */
        h2o_http2_stream_t *stream = H2O_STRUCT_FROM_MEMBER(h2o_http2_stream_t, _refs.link, conn->_pending_reqs.next);
        h2o_linklist_unlink(&stream->_refs.link);
        /* handle it */
        h2o_http2_stream_set_state(conn, stream, H2O_HTTP2_STREAM_STATE_SEND_HEADERS);
        if (!h2o_http2_stream_is_push(stream->stream_id) && conn->pull_stream_ids.max_processed < stream->stream_id)
            conn->pull_stream_ids.max_processed = stream->stream_id;
        h2o_process_request(&stream->req);
    }

    conn->_is_dispatching_pending_reqs = 0;
}
示例#17
0
文件: scheduler.c 项目: pmeenan/h2o
static void do_rebind(h2o_http2_scheduler_openref_t *ref, h2o_http2_scheduler_node_t *new_parent, int exclusive)
{
    /* rebind _all_link */
    h2o_linklist_unlink(&ref->_all_link);
    h2o_linklist_insert(&new_parent->_all_refs, &ref->_all_link);
    /* rebind to WRR (as well as adjust active_cnt) */
    if (ref->_active_cnt != 0) {
        queue_unset(&ref->_queue_node);
        queue_set(get_queue(new_parent), &ref->_queue_node, ref->weight);
        decr_active_cnt(ref->node._parent);
        incr_active_cnt(new_parent);
    }
    /* update the backlinks */
    ref->node._parent = new_parent;

    if (exclusive)
        convert_to_exclusive(new_parent, ref);
}
示例#18
0
文件: memcached.c 项目: Handy2015/h2o
void h2o_memcached_receiver(h2o_multithread_receiver_t *receiver, h2o_linklist_t *messages)
{
    while (!h2o_linklist_is_empty(messages)) {
        h2o_memcached_req_t *req = H2O_STRUCT_FROM_MEMBER(h2o_memcached_req_t, data.get.message.link, messages->next);
        h2o_linklist_unlink(&req->data.get.message.link);
        assert(req->type == REQ_TYPE_GET);
        if (req->data.get.cb != NULL) {
            if (req->data.get.value_is_encoded && req->data.get.value.len != 0) {
                h2o_iovec_t decoded = h2o_decode_base64url(NULL, req->data.get.value.base, req->data.get.value.len);
                h2o_mem_set_secure(req->data.get.value.base, 0, req->data.get.value.len);
                free(req->data.get.value.base);
                req->data.get.value = decoded;
            }
            req->data.get.cb(req->data.get.value, req->data.get.cb_data);
        }
        free_req(req);
    }
}
示例#19
0
文件: hostinfo.c 项目: topcpporg/h2
void h2o_hostinfo_getaddr_cancel(h2o_hostinfo_getaddr_req_t *req)
{
    int should_free = 0;

    pthread_mutex_lock(&queue.mutex);

    if (h2o_linklist_is_linked(&req->_pending)) {
        h2o_linklist_unlink(&req->_pending);
        should_free = 1;
    } else {
        req->_cb = NULL;
    }

    pthread_mutex_unlock(&queue.mutex);

    if (should_free)
        free(req);
}
示例#20
0
文件: hostinfo.c 项目: topcpporg/h2
static void *lookup_thread_main(void *_unused)
{
    pthread_mutex_lock(&queue.mutex);

    while (1) {
        --queue.num_threads_idle;
        while (!h2o_linklist_is_empty(&queue.pending)) {
            h2o_hostinfo_getaddr_req_t *req = H2O_STRUCT_FROM_MEMBER(h2o_hostinfo_getaddr_req_t, _pending, queue.pending.next);
            h2o_linklist_unlink(&req->_pending);
            pthread_mutex_unlock(&queue.mutex);
            lookup_and_respond(req);
            pthread_mutex_lock(&queue.mutex);
        }
        ++queue.num_threads_idle;
        pthread_cond_wait(&queue.cond, &queue.mutex);
    }

    h2o_fatal("unreachable");
    return NULL;
}
示例#21
0
文件: scheduler.c 项目: pmeenan/h2o
void h2o_http2_scheduler_close(h2o_http2_scheduler_openref_t *ref)
{
    assert(h2o_http2_scheduler_is_open(ref));

    /* move dependents to parent */
    if (!h2o_linklist_is_empty(&ref->node._all_refs)) {
        /* proportionally distribute the weight to the children (draft-16 5.3.4) */
        uint32_t total_weight = 0, factor;
        h2o_linklist_t *link;
        for (link = ref->node._all_refs.next; link != &ref->node._all_refs; link = link->next) {
            h2o_http2_scheduler_openref_t *child_ref = H2O_STRUCT_FROM_MEMBER(h2o_http2_scheduler_openref_t, _all_link, link);
            total_weight += child_ref->weight;
        }
        assert(total_weight != 0);
        factor = ((uint32_t)ref->weight * 65536 + total_weight / 2) / total_weight;
        do {
            h2o_http2_scheduler_openref_t *child_ref =
                H2O_STRUCT_FROM_MEMBER(h2o_http2_scheduler_openref_t, _all_link, ref->node._all_refs.next);
            uint16_t weight = (child_ref->weight * factor / 32768 + 1) / 2;
            if (weight < 1)
                weight = 1;
            else if (weight > 256)
                weight = 256;
            h2o_http2_scheduler_rebind(child_ref, ref->node._parent, weight, 0);
        } while (!h2o_linklist_is_empty(&ref->node._all_refs));
    }

    free(ref->node._queue);
    ref->node._queue = NULL;

    /* detach self */
    h2o_linklist_unlink(&ref->_all_link);
    if (ref->_self_is_active) {
        assert(ref->_active_cnt == 1);
        queue_unset(&ref->_queue_node);
        decr_active_cnt(ref->node._parent);
    } else {
        assert(ref->_active_cnt == 0);
    }
}
示例#22
0
h2o_cache_ref_t *h2o_cache_fetch(h2o_cache_t *cache, uint64_t now, h2o_iovec_t key, h2o_cache_hashcode_t keyhash)
{
    h2o_cache_ref_t search_key, *ref;
    khiter_t iter;
    int64_t timeleft;

    if (keyhash == 0)
        keyhash = h2o_cache_calchash(key.base, key.len);
    search_key.key = key;
    search_key.keyhash = keyhash;

    lock_cache(cache);

    purge(cache, now);

    if ((iter = kh_get(cache, cache->table, &search_key)) == kh_end(cache->table))
        goto NotFound;

    /* found */
    ref = kh_key(cache->table, iter);
    timeleft = get_timeleft(cache, ref, now);
    if (timeleft < 0)
        goto NotFound;
    if ((cache->flags & H2O_CACHE_FLAG_EARLY_UPDATE) != 0 && timeleft < 10 && !ref->_requested_early_update) {
        ref->_requested_early_update = 1;
        goto NotFound;
    }
    /* move the entry to the top of LRU */
    h2o_linklist_unlink(&ref->_lru_link);
    h2o_linklist_insert(&cache->lru, &ref->_lru_link);
    __sync_fetch_and_add(&ref->_refcnt, 1);

    /* unlock and return the found entry */
    unlock_cache(cache);
    return ref;

NotFound:
    unlock_cache(cache);
    return NULL;
}
示例#23
0
文件: memcached.c 项目: Handy2015/h2o
static h2o_memcached_req_t *pop_inflight(struct st_h2o_memcached_conn_t *conn, uint32_t serial)
{
    h2o_memcached_req_t *req;
    h2o_linklist_t *node;

    pthread_mutex_lock(&conn->mutex);

    for (node = conn->inflight.next; node != &conn->inflight; node = node->next) {
        req = H2O_STRUCT_FROM_MEMBER(h2o_memcached_req_t, inflight, node);
        assert(req->type == REQ_TYPE_GET);
        if (req->data.get.serial == serial) {
            h2o_linklist_unlink(&req->inflight);
            goto Found;
        }
    }
    req = NULL;
Found:

    pthread_mutex_unlock(&conn->mutex);

    return req;
}
示例#24
0
static void queue_cb(h2o_multithread_queue_t *queue)
{
    pthread_mutex_lock(&queue->mutex);

    while (!h2o_linklist_is_empty(&queue->receivers.active)) {
        h2o_multithread_receiver_t *receiver =
            H2O_STRUCT_FROM_MEMBER(h2o_multithread_receiver_t, _link, queue->receivers.active.next);
        /* detach all the messages from the receiver */
        h2o_linklist_t messages;
        h2o_linklist_init_anchor(&messages);
        h2o_linklist_insert_list(&messages, &receiver->_messages);
        /* relink the receiver to the inactive list */
        h2o_linklist_unlink(&receiver->_link);
        h2o_linklist_insert(&queue->receivers.inactive, &receiver->_link);

        /* dispatch the messages */
        pthread_mutex_unlock(&queue->mutex);
        receiver->cb(receiver, &messages);
        assert(h2o_linklist_is_empty(&messages));
        pthread_mutex_lock(&queue->mutex);
    }

    pthread_mutex_unlock(&queue->mutex);
}
示例#25
0
文件: scheduler.c 项目: pmeenan/h2o
static void queue_unset(h2o_http2_scheduler_queue_node_t *node)
{
    assert(h2o_linklist_is_linked(&node->_link));
    h2o_linklist_unlink(&node->_link);
}
示例#26
0
static void destroy_attached(struct pool_entry_t *entry)
{
    h2o_linklist_unlink(&entry->link);
    h2o_socket_dispose_export(&entry->sockinfo);
    free(entry);
}
示例#27
0
static void destroy_attached(struct pool_entry_t *entry)
{
    h2o_linklist_unlink(&entry->link);
    destroy_detached(entry);
}
示例#28
0
static void pop_empty_message(h2o_linklist_t *list)
{
    h2o_multithread_message_t *message = H2O_STRUCT_FROM_MEMBER(h2o_multithread_message_t, link, list->next);
    h2o_linklist_unlink(&message->link);
    free(message);
}
示例#29
0
void h2o_socketpool_connect(h2o_socketpool_connect_request_t **_req, h2o_socketpool_t *pool, h2o_loop_t *loop,
                            h2o_multithread_receiver_t *getaddr_receiver, h2o_socketpool_connect_cb cb, void *data)
{
    struct pool_entry_t *entry = NULL;

    if (_req != NULL)
        *_req = NULL;

    /* fetch an entry and return it */
    pthread_mutex_lock(&pool->_shared.mutex);
    destroy_expired(pool);
    while (1) {
        if (h2o_linklist_is_empty(&pool->_shared.sockets))
            break;
        entry = H2O_STRUCT_FROM_MEMBER(struct pool_entry_t, link, pool->_shared.sockets.next);
        h2o_linklist_unlink(&entry->link);
        pthread_mutex_unlock(&pool->_shared.mutex);

        /* test if the connection is still alive */
        char buf[1];
        ssize_t rret = recv(entry->sockinfo.fd, buf, 1, MSG_PEEK);
        if (rret == -1 && (errno == EAGAIN || errno == EWOULDBLOCK)) {
            /* yes! return it */
            h2o_socket_t *sock = h2o_socket_import(loop, &entry->sockinfo);
            free(entry);
            sock->on_close.cb = on_close;
            sock->on_close.data = pool;
            cb(sock, NULL, data);
            return;
        }

        /* connection is dead, report, close, and retry */
        if (rret <= 0) {
            static long counter = 0;
            if (__sync_fetch_and_add(&counter, 1) == 0)
                fprintf(stderr, "[WARN] detected close by upstream before the expected timeout (see issue #679)\n");
        } else {
            static long counter = 0;
            if (__sync_fetch_and_add(&counter, 1) == 0)
                fprintf(stderr, "[WARN] unexpectedly received data to a pooled socket (see issue #679)\n");
        }
        destroy_detached(entry);
        pthread_mutex_lock(&pool->_shared.mutex);
    }
    pthread_mutex_unlock(&pool->_shared.mutex);

    /* FIXME repsect `capacity` */
    __sync_add_and_fetch(&pool->_shared.count, 1);

    /* prepare request object */
    h2o_socketpool_connect_request_t *req = h2o_mem_alloc(sizeof(*req));
    *req = (h2o_socketpool_connect_request_t){data, cb, pool, loop};
    if (_req != NULL)
        *_req = req;

    switch (pool->type) {
    case H2O_SOCKETPOOL_TYPE_NAMED:
        /* resolve the name, and connect */
        req->getaddr_req = h2o_hostinfo_getaddr(getaddr_receiver, pool->peer.host, pool->peer.named_serv, AF_UNSPEC, SOCK_STREAM,
                                                IPPROTO_TCP, AI_ADDRCONFIG | AI_NUMERICSERV, on_getaddr, req);
        break;
    case H2O_SOCKETPOOL_TYPE_SOCKADDR:
        /* connect (using sockaddr_in) */
        start_connect(req, (void *)&pool->peer.sockaddr.bytes, pool->peer.sockaddr.len);
        break;
    }
}
示例#30
0
文件: memcached.c 项目: Handy2015/h2o
static void reader_main(h2o_memcached_context_t *ctx)
{
    struct st_h2o_memcached_conn_t conn = {ctx, {}, PTHREAD_MUTEX_INITIALIZER, {&conn.inflight, &conn.inflight}, 0};
    pthread_t writer_thread;
    yrmcds_response resp;
    yrmcds_error err;

    /* connect to server and start the writer thread */
    connect_to_server(conn.ctx, &conn.yrmcds);
    pthread_create(&writer_thread, NULL, writer_main, &conn);

    pthread_mutex_lock(&conn.ctx->mutex);
    ++conn.ctx->num_threads_connected;
    pthread_mutex_unlock(&conn.ctx->mutex);

    /* receive data until an error occurs */
    while (1) {
        if ((err = yrmcds_recv(&conn.yrmcds, &resp)) != YRMCDS_OK) {
            fprintf(stderr, "[lib/common/memcached.c] yrmcds_recv:%s\n", yrmcds_strerror(err));
            break;
        }
        h2o_memcached_req_t *req = pop_inflight(&conn, resp.serial);
        if (req == NULL) {
            fprintf(stderr, "[lib/common/memcached.c] received unexpected serial\n");
            break;
        }
        if (resp.status == YRMCDS_STATUS_OK) {
            req->data.get.value = h2o_iovec_init(h2o_mem_alloc(resp.data_len), resp.data_len);
            memcpy(req->data.get.value.base, resp.data, resp.data_len);
            h2o_mem_set_secure((void *)resp.data, 0, resp.data_len);
        }
        h2o_multithread_send_message(req->data.get.receiver, &req->data.get.message);
    }

    /* send error to all the reqs in-flight */
    pthread_mutex_lock(&conn.mutex);
    while (!h2o_linklist_is_empty(&conn.inflight)) {
        h2o_memcached_req_t *req = H2O_STRUCT_FROM_MEMBER(h2o_memcached_req_t, inflight, conn.inflight.next);
        h2o_linklist_unlink(&req->inflight);
        assert(req->type == REQ_TYPE_GET);
        h2o_multithread_send_message(req->data.get.receiver, &req->data.get.message);
    }
    pthread_mutex_unlock(&conn.mutex);

    /* stop the writer thread */
    __sync_add_and_fetch(&conn.writer_exit_requested, 1);
    pthread_mutex_lock(&conn.ctx->mutex);
    pthread_cond_broadcast(&conn.ctx->cond);
    pthread_mutex_unlock(&conn.ctx->mutex);
    pthread_join(writer_thread, NULL);

    /* decrement num_threads_connected, and discard all the pending requests if no connections are alive */
    pthread_mutex_lock(&conn.ctx->mutex);
    if (--conn.ctx->num_threads_connected == 0) {
        while (!h2o_linklist_is_empty(&conn.ctx->pending)) {
            h2o_memcached_req_t *req = H2O_STRUCT_FROM_MEMBER(h2o_memcached_req_t, pending, conn.ctx->pending.next);
            h2o_linklist_unlink(&req->pending);
            discard_req(req);
        }
    }
    pthread_mutex_unlock(&conn.ctx->mutex);

    /* close the connection */
    yrmcds_close(&conn.yrmcds);
}