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;
}
static void dispatch(h2o_memcached_context_t *ctx, h2o_memcached_req_t *req)
{
pthread_mutex_lock(&ctx->mutex);
if (ctx->num_threads_connected != 0) {
h2o_linklist_insert(&ctx->pending, &req->pending);
pthread_cond_signal(&ctx->cond);
} else {
discard_req(req);
}
pthread_mutex_unlock(&ctx->mutex);
}
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);
}