diff options
Diffstat (limited to 'wsrep-lib/wsrep-API/v26/examples/node/trx.c')
| -rw-r--r-- | wsrep-lib/wsrep-API/v26/examples/node/trx.c | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/wsrep-lib/wsrep-API/v26/examples/node/trx.c b/wsrep-lib/wsrep-API/v26/examples/node/trx.c new file mode 100644 index 00000000..afdcada4 --- /dev/null +++ b/wsrep-lib/wsrep-API/v26/examples/node/trx.c @@ -0,0 +1,155 @@ +/* Copyright (c) 2019-2020, Codership Oy. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; version 2 of the License. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include "trx.h" +#include "log.h" + +#include <assert.h> +#include <errno.h> // ENOMEM, etc. +#include <stdbool.h> + +wsrep_status_t +node_trx_execute(node_store_t* const store, + wsrep_t* const wsrep, + wsrep_conn_id_t const conn_id, + int ops_num) +{ + wsrep_status_t cert = WSREP_OK; // for cleanup + + static unsigned int const ws_flags = + WSREP_FLAG_TRX_START | WSREP_FLAG_TRX_END; // atomic trx + wsrep_trx_meta_t ws_meta; + wsrep_status_t ret = WSREP_OK; + + /* prepare simple transaction and obtain a writeset handle for it */ + wsrep_ws_handle_t ws_handle = { 0, NULL }; + while (ops_num--) + { + if (0 != (ret = node_store_execute(store, wsrep, &ws_handle))) + { +#if 0 + NODE_INFO("master [%d]: node_store_execute() returned %d", + conn_id, ret); +#endif + ret = WSREP_TRX_FAIL; + goto cleanup; + } + } + + /* REPLICATION: (replicate and) certify the writeset (pointed to by + * ws_handle) with the cluster */ + cert = wsrep->certify(wsrep, conn_id, &ws_handle, ws_flags, &ws_meta); + + if (WSREP_BF_ABORT == cert) + { + /* REPLICATION: transaction was signaled to abort due to multi-master + * conflict. It must rollback immediately: it blocks + * transaction that was ordered earlier and will never + * be able to enter commit order. */ + node_store_rollback(store, ws_handle.trx_id); + } + + /* REPLICATION: writeset was totally ordered, need to enter commit order */ + if (ws_meta.gtid.seqno > 0) + { + ret = wsrep->commit_order_enter(wsrep, &ws_handle, &ws_meta); + if (ret) + { + NODE_ERROR("master [%d]: wsrep::commit_order_enter(%lld) failed: " + "%d", (long long)(ws_meta.gtid.seqno), ret); + goto cleanup; + } + + /* REPLICATION: inside commit monitor + * Note: we commit transaction only if certification succeded */ + if (WSREP_OK == cert) + node_store_commit(store, ws_handle.trx_id, &ws_meta.gtid); + else + node_store_update_gtid(store, &ws_meta.gtid); + + ret = wsrep->commit_order_leave(wsrep, &ws_handle, &ws_meta, NULL); + if (ret) + { + NODE_ERROR("master [%d]: wsrep::commit_order_leave(%lld) failed: " + "%d", (long long)(ws_meta.gtid.seqno), ret); + goto cleanup; + } + } + else + { + assert(cert); + } + +cleanup: + /* REPLICATION: if wsrep->certify() returned anything else but WSREP_OK + * transaction must roll back. BF aborted trx already did it. */ + if (cert && WSREP_BF_ABORT != cert) + node_store_rollback(store, ws_handle.trx_id); + + /* NOTE: this application follows the approach that resources must be freed + * at the same level where they were allocated, so it is assumed that + * ws_key and ws were deallocated in either commit or rollback calls.*/ + + /* REPLICATION: release provider resources associated with the trx */ + wsrep->release(wsrep, &ws_handle); + + return ret ? ret : cert; +} + +wsrep_status_t +node_trx_apply(node_store_t* const store, + wsrep_t* const wsrep, + const wsrep_ws_handle_t* const ws_handle, + const wsrep_trx_meta_t* const ws_meta, + const wsrep_buf_t* const ws) +{ + /* no business being here if event was not ordered */ + assert(ws_meta->gtid.seqno > 0); + + wsrep_trx_id_t trx_id; + wsrep_buf_t err_buf = { NULL, 0 }; + int app_err; + if (ws) + { + app_err = node_store_apply(store, &trx_id, ws); + if (app_err) + { + /* REPLICATION: if applying failed, prepare an error buffer with + * sufficient error specification */ + err_buf.ptr = &app_err; // suppose error code is enough + err_buf.len = sizeof(app_err); + } + } + else /* ws failed certification and should be skipped */ + { + /* just some non-0 code to choose node_store_update_gtid() below */ + app_err = 1; + } + + wsrep_status_t ret; + ret = wsrep->commit_order_enter(wsrep, ws_handle, ws_meta); + if (ret) { + node_store_rollback(store, trx_id); + return ret; + } + + if (!app_err) node_store_commit(store, trx_id, &ws_meta->gtid); + else node_store_update_gtid(store, &ws_meta->gtid); + + ret = wsrep->commit_order_leave(wsrep, ws_handle, ws_meta, &err_buf); + + return ret; +} |