Added wsrep specific files

1 files changed, 419 insertions, 0 deletions

diff --git a/sql/wsrep_hton.cc b/sql/wsrep_hton.cc
new file mode 100644
index 00000000000..9986d7c79cd
--- /dev/null
+++ b/sql/wsrep_hton.cc
@@ -0,0 +1,419 @@
+/* Copyright 2008 Codership Oy <http://www.codership.com>
+
+   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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
+
+#include <mysqld.h>
+#include "sql_base.h"
+#include <sql_class.h>
+#include "wsrep_mysqld.h"
+#include "wsrep_priv.h"
+#include <cstdio>
+#include <cstdlib>
+
+extern handlerton *binlog_hton;
+extern int binlog_close_connection(handlerton *hton, THD *thd);
+extern ulonglong thd_to_trx_id(THD *thd);
+
+extern "C" int thd_binlog_format(const MYSQL_THD thd); 
+// todo: share interface with ha_innodb.c 
+
+enum wsrep_trx_status wsrep_run_wsrep_commit(THD *thd, handlerton *hton, bool all);
+
+/*
+  a post-commit cleanup on behalf of wsrep. Can't be a part of hton struct.
+  Is called by THD::transactions.cleanup()
+*/
+void wsrep_cleanup_transaction(THD *thd)
+{
+  if (thd->thread_id == 0) return;
+  if (thd->wsrep_exec_mode == LOCAL_COMMIT)
+  {
+    if (thd->variables.wsrep_on &&
+        thd->wsrep_conflict_state != MUST_REPLAY)
+    {
+      if (thd->wsrep_seqno_changed)
+      {
+	if (wsrep->post_commit(wsrep, &thd->wsrep_trx_handle))
+	{
+	  DBUG_PRINT("wsrep", ("set committed fail"));
+	  WSREP_WARN("set committed fail: %llu %d", 
+		     (long long)thd->real_id, thd->stmt_da->status());
+	}
+      }
+      //else
+      //WSREP_DEBUG("no trx handle for %s", thd->query());
+      thd_binlog_trx_reset(thd);
+      thd->wsrep_seqno_changed = false;
+    }
+    thd->wsrep_exec_mode= LOCAL_STATE;
+  }
+}
+
+/*
+  wsrep hton
+*/
+handlerton *wsrep_hton;
+
+void wsrep_register_hton(THD* thd, bool all)
+{
+  THD_TRANS *trans=all ? &thd->transaction.all : &thd->transaction.stmt;
+  for (Ha_trx_info *i= trans->ha_list; WSREP(thd) && i; i = i->next())
+  {
+    if (i->ht()->db_type == DB_TYPE_INNODB)
+    {
+      trans_register_ha(thd, all, wsrep_hton);
+      thd->ha_data[wsrep_hton->slot].ha_info[all].set_trx_read_write();
+      break;
+    }
+  }
+}
+
+/*
+  wsrep exploits binlog's caches even if binlogging itself is not 
+  activated. In such case connection close needs calling
+  actual binlog's method.
+  Todo: split binlog hton from its caches to use ones by wsrep
+  without referring to binlog's stuff.
+*/
+static int
+wsrep_close_connection(handlerton*  hton, THD* thd)
+{
+  DBUG_ENTER("wsrep_close_connection");
+  if (thd_get_ha_data(thd, binlog_hton) != NULL)
+    binlog_hton->close_connection (binlog_hton, thd);
+  DBUG_RETURN(0);
+} 
+
+/*
+  prepare/wsrep_run_wsrep_commit can fail in two ways
+  - certification test or an equivalent. As a result,
+    the current transaction just rolls back
+    Error codes:
+           WSREP_TRX_ROLLBACK, WSREP_TRX_ERROR
+  - a post-certification failure makes this server unable to
+    commit its own WS and therefore the server must abort
+*/
+static int wsrep_prepare(handlerton *hton, THD *thd, bool all)
+{
+#ifndef DBUG_OFF
+  //wsrep_seqno_t old = thd->wsrep_trx_seqno;
+#endif
+  DBUG_ENTER("wsrep_prepare");
+  if ((all || 
+      !thd_test_options(thd, OPTION_NOT_AUTOCOMMIT | OPTION_BEGIN)) &&
+      (thd->variables.wsrep_on && !wsrep_trans_cache_is_empty(thd)))
+  {
+    switch (wsrep_run_wsrep_commit(thd, hton, all))
+    {
+    case WSREP_TRX_OK:
+      //  DBUG_ASSERT(thd->wsrep_trx_seqno > old       ||
+      //	  thd->wsrep_exec_mode == REPL_RECV    ||
+      //	  thd->wsrep_exec_mode == TOTAL_ORDER);
+      break;
+    case WSREP_TRX_ROLLBACK:
+    case WSREP_TRX_ERROR:
+      DBUG_RETURN(1);
+    }
+  }
+  DBUG_RETURN(0);
+}
+
+static int wsrep_savepoint_set(handlerton *hton, THD *thd,  void *sv)
+{
+  if (!wsrep_emulate_bin_log) return 0;
+  int rcode = binlog_hton->savepoint_set(binlog_hton, thd, sv);
+  return rcode;
+}
+static int wsrep_savepoint_rollback(handlerton *hton, THD *thd, void *sv)
+{
+  if (!wsrep_emulate_bin_log) return 0;
+  int rcode = binlog_hton->savepoint_rollback(binlog_hton, thd, sv);
+  return rcode;
+}
+
+static int wsrep_rollback(handlerton *hton, THD *thd, bool all)
+{
+  DBUG_ENTER("wsrep_rollback");
+  mysql_mutex_lock(&thd->LOCK_wsrep_thd);
+  if ((all || !thd_test_options(thd, OPTION_NOT_AUTOCOMMIT | OPTION_BEGIN)) &&
+      (thd->variables.wsrep_on && thd->wsrep_conflict_state != MUST_REPLAY))
+  {
+    if (wsrep->post_rollback(wsrep, &thd->wsrep_trx_handle))
+    {
+      DBUG_PRINT("wsrep", ("setting rollback fail"));
+      WSREP_ERROR("settting rollback fail: thd: %llu SQL: %s", 
+		  (long long)thd->real_id, thd->query());
+    }
+  }
+
+  int rcode = 0;
+  if (!wsrep_emulate_bin_log) 
+  {
+    if (all) thd_binlog_trx_reset(thd);
+  }
+
+  mysql_mutex_unlock(&thd->LOCK_wsrep_thd);
+  DBUG_RETURN(rcode);
+}
+
+int wsrep_commit(handlerton *hton, THD *thd, bool all)
+{
+  DBUG_ENTER("wsrep_commit");
+
+  DBUG_RETURN(0);
+}
+
+extern my_bool opt_log_slave_updates;
+enum wsrep_trx_status
+wsrep_run_wsrep_commit(
+    THD *thd, handlerton *hton, bool all)
+{
+  int rcode         = -1;
+  uint data_len     = 0;
+  uchar *rbr_data   = NULL;
+  IO_CACHE *cache;
+  int replay_round= 0;
+
+  if (thd->stmt_da->is_error()) {
+    WSREP_ERROR("commit issue, error: %d %s", 
+                thd->stmt_da->sql_errno(), thd->stmt_da->message());
+  }
+
+  DBUG_ENTER("wsrep_run_wsrep_commit");
+  if (thd->slave_thread && !opt_log_slave_updates) {
+    DBUG_RETURN(WSREP_TRX_OK);
+  }
+  if (thd->wsrep_exec_mode == REPL_RECV) {
+
+    mysql_mutex_lock(&thd->LOCK_wsrep_thd);
+    if (thd->wsrep_conflict_state == MUST_ABORT) {
+      if (wsrep_debug)
+        WSREP_INFO("WSREP: must abort for BF");
+      DBUG_PRINT("wsrep", ("BF apply commit fail"));
+      thd->wsrep_conflict_state = NO_CONFLICT;
+      mysql_mutex_unlock(&thd->LOCK_wsrep_thd);
+      //
+      // TODO: test all calls of the rollback.
+      // rollback must happen automagically innobase_rollback(hton, thd, 1);
+      //
+      DBUG_RETURN(WSREP_TRX_ERROR);
+    }
+    mysql_mutex_unlock(&thd->LOCK_wsrep_thd);
+  }
+  if (thd->wsrep_exec_mode != LOCAL_STATE) {
+    DBUG_RETURN(WSREP_TRX_OK);
+  }
+  if (thd->wsrep_consistency_check) {
+    WSREP_DEBUG("commit for consistency check: %s", thd->query());
+    DBUG_RETURN(WSREP_TRX_OK);
+  }
+
+  DBUG_PRINT("wsrep", ("replicating commit"));
+
+  mysql_mutex_lock(&thd->LOCK_wsrep_thd);
+  if (thd->wsrep_conflict_state == MUST_ABORT) {
+    DBUG_PRINT("wsrep", ("replicate commit fail"));
+    thd->wsrep_conflict_state = ABORTED;
+    mysql_mutex_unlock(&thd->LOCK_wsrep_thd);
+    if (wsrep_debug) {
+      WSREP_INFO("innobase_commit, abort %s",
+                 (thd->query()) ? thd->query() : "void");
+    }
+    DBUG_RETURN(WSREP_TRX_ROLLBACK);
+  }
+
+  mysql_mutex_lock(&LOCK_wsrep_replaying);
+
+  while (wsrep_replaying > 0                       && 
+         thd->wsrep_conflict_state == NO_CONFLICT  &&
+         thd->killed == NOT_KILLED                 &&
+         !shutdown_in_progress) {
+
+    mysql_mutex_unlock(&LOCK_wsrep_replaying);
+    mysql_mutex_unlock(&thd->LOCK_wsrep_thd);
+
+    mysql_mutex_lock(&thd->mysys_var->mutex);
+    thd_proc_info(thd, "wsrep waiting on replaying");
+    thd->mysys_var->current_mutex= &LOCK_wsrep_replaying;
+    thd->mysys_var->current_cond=  &COND_wsrep_replaying;
+    mysql_mutex_unlock(&thd->mysys_var->mutex);
+
+    mysql_mutex_lock(&LOCK_wsrep_replaying);
+    // Using timedwait is a hack to avoid deadlock in case if BF victim
+    // misses the signal.
+    struct timespec wtime = {0, 1000000};
+    mysql_cond_timedwait(&COND_wsrep_replaying, &LOCK_wsrep_replaying,
+			 &wtime);
+    if (replay_round++ % 100000 == 0)
+      WSREP_DEBUG("commit waiting for replaying: replayers %d, thd: (%lu) conflict: %d (round: %d)", 
+		  wsrep_replaying, thd->thread_id, thd->wsrep_conflict_state, replay_round);
+
+    mysql_mutex_unlock(&LOCK_wsrep_replaying);
+
+    mysql_mutex_lock(&thd->mysys_var->mutex);
+    thd->mysys_var->current_mutex= 0;
+    thd->mysys_var->current_cond=  0;
+    mysql_mutex_unlock(&thd->mysys_var->mutex);
+
+    mysql_mutex_lock(&thd->LOCK_wsrep_thd);
+    mysql_mutex_lock(&LOCK_wsrep_replaying);
+  }
+  mysql_mutex_unlock(&LOCK_wsrep_replaying);
+
+  if (thd->wsrep_conflict_state == MUST_ABORT) {
+    DBUG_PRINT("wsrep", ("replicate commit fail"));
+    thd->wsrep_conflict_state = ABORTED;
+    mysql_mutex_unlock(&thd->LOCK_wsrep_thd);
+    WSREP_DEBUG("innobase_commit abort after replaying wait %s",
+                (thd->query()) ? thd->query() : "void");
+    DBUG_RETURN(WSREP_TRX_ROLLBACK);
+  }  thd->wsrep_query_state = QUERY_COMMITTING;
+  mysql_mutex_unlock(&thd->LOCK_wsrep_thd);
+
+  cache = get_trans_log(thd);
+  rcode = 0;
+  if (cache) {
+    thd->binlog_flush_pending_rows_event(true);
+    rcode = wsrep_write_cache(cache, &rbr_data, &data_len);
+    if (rcode) {
+      WSREP_ERROR("rbr write fail, data_len: %d, %d", data_len, rcode);
+      if (data_len) my_free(rbr_data);
+      DBUG_RETURN(WSREP_TRX_ROLLBACK);
+    }
+  }
+  if (data_len == 0) 
+  {
+    mysql_mutex_lock(&thd->LOCK_wsrep_thd);
+    thd->wsrep_exec_mode = LOCAL_COMMIT;
+    WSREP_DEBUG("empty rbr buffer, query: %s", thd->query());
+    mysql_mutex_unlock(&thd->LOCK_wsrep_thd);
+    DBUG_RETURN(WSREP_TRX_OK);
+  }
+  if (!rcode) {
+    rcode = wsrep->pre_commit(
+                              wsrep,
+                              (wsrep_conn_id_t)thd->thread_id,
+                              &thd->wsrep_trx_handle,
+                              rbr_data,
+                              data_len,
+                              (thd->wsrep_PA_safe) ? WSREP_FLAG_PA_SAFE : 0ULL,
+                              &thd->wsrep_trx_seqno);
+    if (rcode == WSREP_TRX_MISSING) {
+      rcode = WSREP_OK;
+    } else if (rcode == WSREP_BF_ABORT) {
+      mysql_mutex_lock(&thd->LOCK_wsrep_thd);
+      thd->wsrep_conflict_state = MUST_REPLAY;
+      mysql_mutex_unlock(&thd->LOCK_wsrep_thd);
+      mysql_mutex_lock(&LOCK_wsrep_replaying);
+      wsrep_replaying++;
+      WSREP_DEBUG("replaying increased: %d, thd: %lu",
+                  wsrep_replaying, thd->thread_id);
+      mysql_mutex_unlock(&LOCK_wsrep_replaying);
+    }
+    thd->wsrep_seqno_changed = true;
+  } else {
+    WSREP_ERROR("I/O error reading from thd's binlog iocache: "
+                "errno=%d, io cache code=%d", my_errno, cache->error);
+    if (data_len) my_free(rbr_data);
+    DBUG_ASSERT(0); // failure like this can not normally happen
+    DBUG_RETURN(WSREP_TRX_ERROR);
+  }
+
+  if (data_len) {
+    my_free(rbr_data);
+  }
+
+  mysql_mutex_lock(&thd->LOCK_wsrep_thd);
+  switch(rcode) {
+  case 0:
+    thd->wsrep_exec_mode = LOCAL_COMMIT;
+    /* Override XID iff it was generated by mysql */
+    if (thd->transaction.xid_state.xid.get_my_xid())
+    {
+      wsrep_xid_init(&thd->transaction.xid_state.xid,
+                     wsrep_cluster_uuid(),
+                     thd->wsrep_trx_seqno);
+    }
+    DBUG_PRINT("wsrep", ("replicating commit success"));
+
+    break;
+  case WSREP_TRX_FAIL:
+  case WSREP_BF_ABORT:
+    WSREP_DEBUG("commit failed for reason: %d", rcode);
+    DBUG_PRINT("wsrep", ("replicating commit fail"));
+
+    thd->wsrep_query_state= QUERY_EXEC;
+
+    if (thd->wsrep_conflict_state == MUST_ABORT) {
+      thd->wsrep_conflict_state= ABORTED;
+    }
+    mysql_mutex_unlock(&thd->LOCK_wsrep_thd);
+
+    DBUG_RETURN(WSREP_TRX_ROLLBACK);
+
+  case WSREP_CONN_FAIL:
+    WSREP_ERROR("connection failure");
+    DBUG_RETURN(WSREP_TRX_ERROR);
+  default:
+    WSREP_ERROR("unknown connection failure");
+    DBUG_RETURN(WSREP_TRX_ERROR);
+  }
+
+  thd->wsrep_query_state= QUERY_EXEC;
+  mysql_mutex_unlock(&thd->LOCK_wsrep_thd);
+
+  DBUG_RETURN(WSREP_TRX_OK);
+}
+
+
+static int wsrep_hton_init(void *p)
+{
+  wsrep_hton= (handlerton *)p;
+  //wsrep_hton->state=opt_bin_log ? SHOW_OPTION_YES : SHOW_OPTION_NO;
+  wsrep_hton->state= SHOW_OPTION_YES;
+  wsrep_hton->db_type=DB_TYPE_WSREP;
+  wsrep_hton->savepoint_offset= sizeof(my_off_t);
+  wsrep_hton->close_connection= wsrep_close_connection;
+  wsrep_hton->savepoint_set= wsrep_savepoint_set;
+  wsrep_hton->savepoint_rollback= wsrep_savepoint_rollback;
+  wsrep_hton->commit= wsrep_commit;
+  wsrep_hton->rollback= wsrep_rollback;
+  wsrep_hton->prepare= wsrep_prepare;
+  wsrep_hton->flags= HTON_NOT_USER_SELECTABLE | HTON_HIDDEN; // todo: fix flags
+  wsrep_hton->slot= 0;
+  return 0;
+}
+
+
+struct st_mysql_storage_engine wsrep_storage_engine=
+{ MYSQL_HANDLERTON_INTERFACE_VERSION };
+
+
+mysql_declare_plugin(wsrep)
+{
+  MYSQL_STORAGE_ENGINE_PLUGIN,
+  &wsrep_storage_engine,
+  "wsrep",
+  "Codership Oy",
+  "A pseudo storage engine to represent transactions in multi-master synchornous replication",
+  PLUGIN_LICENSE_GPL,
+  wsrep_hton_init, /* Plugin Init */
+  NULL, /* Plugin Deinit */
+  0x0100 /* 1.0 */,
+  NULL,                       /* status variables                */
+  NULL,                       /* system variables                */
+  NULL,                        /* config options                  */
+  0,                          /* flags                           */
+}
+mysql_declare_plugin_end;