mariadb/sql/wsrep_thd.cc
Sergei Golubchik a2330c820a MDEV-8208 Sporadic SEGFAULT on startup
different fix. remove old ones, wait for THD to be fully
initialized before continuing with the server startup process.

This reverts commits db2e21b, 13615c5, 3f515a0, 70113ee.
2016-01-25 17:04:09 +01:00

632 lines
19 KiB
C++

/* Copyright (C) 2013 Codership Oy <info@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.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */
#include "wsrep_thd.h"
#include "transaction.h"
#include "rpl_rli.h"
#include "log_event.h"
#include "sql_parse.h"
//#include "global_threads.h" // LOCK_thread_count, etc.
#include "sql_base.h" // close_thread_tables()
#include "mysqld.h" // start_wsrep_THD();
#include "slave.h" // opt_log_slave_updates
#include "rpl_filter.h"
#include "rpl_rli.h"
#include "rpl_mi.h"
#if (__LP64__)
static volatile int64 wsrep_bf_aborts_counter(0);
#define WSREP_ATOMIC_LOAD_LONG my_atomic_load64
#define WSREP_ATOMIC_ADD_LONG my_atomic_add64
#else
static volatile int32 wsrep_bf_aborts_counter(0);
#define WSREP_ATOMIC_LOAD_LONG my_atomic_load32
#define WSREP_ATOMIC_ADD_LONG my_atomic_add32
#endif
int wsrep_show_bf_aborts (THD *thd, SHOW_VAR *var, char *buff,
enum enum_var_type scope)
{
wsrep_local_bf_aborts = WSREP_ATOMIC_LOAD_LONG(&wsrep_bf_aborts_counter);
var->type = SHOW_LONGLONG;
var->value = (char*)&wsrep_local_bf_aborts;
return 0;
}
/* must have (&thd->LOCK_wsrep_thd) */
void wsrep_client_rollback(THD *thd)
{
WSREP_DEBUG("client rollback due to BF abort for (%ld), query: %s",
thd->thread_id, thd->query());
WSREP_ATOMIC_ADD_LONG(&wsrep_bf_aborts_counter, 1);
thd->wsrep_conflict_state= ABORTING;
mysql_mutex_unlock(&thd->LOCK_wsrep_thd);
trans_rollback(thd);
if (thd->locked_tables_mode && thd->lock)
{
WSREP_DEBUG("unlocking tables for BF abort (%ld)", thd->thread_id);
thd->locked_tables_list.unlock_locked_tables(thd);
thd->variables.option_bits&= ~(OPTION_TABLE_LOCK);
}
if (thd->global_read_lock.is_acquired())
{
WSREP_DEBUG("unlocking GRL for BF abort (%ld)", thd->thread_id);
thd->global_read_lock.unlock_global_read_lock(thd);
}
/* Release transactional metadata locks. */
thd->mdl_context.release_transactional_locks();
/* release explicit MDL locks */
thd->mdl_context.release_explicit_locks();
if (thd->get_binlog_table_maps())
{
WSREP_DEBUG("clearing binlog table map for BF abort (%ld)", thd->thread_id);
thd->clear_binlog_table_maps();
}
mysql_mutex_lock(&thd->LOCK_wsrep_thd);
thd->wsrep_conflict_state= ABORTED;
}
#define NUMBER_OF_FIELDS_TO_IDENTIFY_COORDINATOR 1
#define NUMBER_OF_FIELDS_TO_IDENTIFY_WORKER 2
static rpl_group_info* wsrep_relay_group_init(const char* log_fname)
{
Relay_log_info* rli= new Relay_log_info(false);
rli->no_storage= true;
if (!rli->relay_log.description_event_for_exec)
{
rli->relay_log.description_event_for_exec=
new Format_description_log_event(4);
}
static LEX_STRING connection_name= { C_STRING_WITH_LEN("wsrep") };
/*
Master_info's constructor initializes rpl_filter by either an already
constructed Rpl_filter object from global 'rpl_filters' list if the
specified connection name is same, or it constructs a new Rpl_filter
object and adds it to rpl_filters. This object is later destructed by
Mater_info's destructor by looking it up based on connection name in
rpl_filters list.
However, since all Master_info objects created here would share same
connection name ("wsrep"), destruction of any of the existing Master_info
objects (in wsrep_return_from_bf_mode()) would free rpl_filter referenced
by any/all existing Master_info objects.
In order to avoid that, we have added a check in Master_info's destructor
to not free the "wsrep" rpl_filter. It will eventually be freed by
free_all_rpl_filters() when server terminates.
*/
rli->mi = new Master_info(&connection_name, false);
struct rpl_group_info *rgi= new rpl_group_info(rli);
rgi->thd= rli->sql_driver_thd= current_thd;
if ((rgi->deferred_events_collecting= rli->mi->rpl_filter->is_on()))
{
rgi->deferred_events= new Deferred_log_events(rli);
}
return rgi;
}
static void wsrep_prepare_bf_thd(THD *thd, struct wsrep_thd_shadow* shadow)
{
shadow->options = thd->variables.option_bits;
shadow->server_status = thd->server_status;
shadow->wsrep_exec_mode = thd->wsrep_exec_mode;
shadow->vio = thd->net.vio;
if (opt_log_slave_updates)
thd->variables.option_bits|= OPTION_BIN_LOG;
else
thd->variables.option_bits&= ~(OPTION_BIN_LOG);
if (!thd->wsrep_rgi) thd->wsrep_rgi= wsrep_relay_group_init("wsrep_relay");
/* thd->system_thread_info.rpl_sql_info isn't initialized. */
thd->system_thread_info.rpl_sql_info=
new rpl_sql_thread_info(thd->wsrep_rgi->rli->mi->rpl_filter);
thd->wsrep_exec_mode= REPL_RECV;
thd->net.vio= 0;
thd->clear_error();
shadow->tx_isolation = thd->variables.tx_isolation;
thd->variables.tx_isolation = ISO_READ_COMMITTED;
thd->tx_isolation = ISO_READ_COMMITTED;
shadow->db = thd->db;
shadow->db_length = thd->db_length;
thd->reset_db(NULL, 0);
}
static void wsrep_return_from_bf_mode(THD *thd, struct wsrep_thd_shadow* shadow)
{
thd->variables.option_bits = shadow->options;
thd->server_status = shadow->server_status;
thd->wsrep_exec_mode = shadow->wsrep_exec_mode;
thd->net.vio = shadow->vio;
thd->variables.tx_isolation = shadow->tx_isolation;
thd->reset_db(shadow->db, shadow->db_length);
delete thd->system_thread_info.rpl_sql_info;
delete thd->wsrep_rgi->rli->mi;
delete thd->wsrep_rgi->rli;
thd->wsrep_rgi->cleanup_after_session();
delete thd->wsrep_rgi;
thd->wsrep_rgi = NULL;
}
void wsrep_replay_transaction(THD *thd)
{
/* checking if BF trx must be replayed */
if (thd->wsrep_conflict_state== MUST_REPLAY) {
DBUG_ASSERT(wsrep_thd_trx_seqno(thd));
if (thd->wsrep_exec_mode!= REPL_RECV) {
if (thd->get_stmt_da()->is_sent())
{
WSREP_ERROR("replay issue, thd has reported status already");
}
thd->get_stmt_da()->reset_diagnostics_area();
thd->wsrep_conflict_state= REPLAYING;
mysql_mutex_unlock(&thd->LOCK_wsrep_thd);
thd->reset_for_next_command();
thd->killed= NOT_KILLED;
close_thread_tables(thd);
if (thd->locked_tables_mode && thd->lock)
{
WSREP_DEBUG("releasing table lock for replaying (%ld)",
thd->thread_id);
thd->locked_tables_list.unlock_locked_tables(thd);
thd->variables.option_bits&= ~(OPTION_TABLE_LOCK);
}
thd->mdl_context.release_transactional_locks();
/*
Replaying will call MYSQL_START_STATEMENT when handling
BEGIN Query_log_event so end statement must be called before
replaying.
*/
MYSQL_END_STATEMENT(thd->m_statement_psi, thd->get_stmt_da());
thd->m_statement_psi= NULL;
thd->m_digest= NULL;
thd_proc_info(thd, "wsrep replaying trx");
WSREP_DEBUG("replay trx: %s %lld",
thd->query() ? thd->query() : "void",
(long long)wsrep_thd_trx_seqno(thd));
struct wsrep_thd_shadow shadow;
wsrep_prepare_bf_thd(thd, &shadow);
/* From trans_begin() */
thd->variables.option_bits|= OPTION_BEGIN;
thd->server_status|= SERVER_STATUS_IN_TRANS;
int rcode = wsrep->replay_trx(wsrep,
&thd->wsrep_ws_handle,
(void *)thd);
wsrep_return_from_bf_mode(thd, &shadow);
if (thd->wsrep_conflict_state!= REPLAYING)
WSREP_WARN("lost replaying mode: %d", thd->wsrep_conflict_state );
mysql_mutex_lock(&thd->LOCK_wsrep_thd);
switch (rcode)
{
case WSREP_OK:
thd->wsrep_conflict_state= NO_CONFLICT;
wsrep->post_commit(wsrep, &thd->wsrep_ws_handle);
WSREP_DEBUG("trx_replay successful for: %ld %llu",
thd->thread_id, (long long)thd->real_id);
if (thd->get_stmt_da()->is_sent())
{
WSREP_WARN("replay ok, thd has reported status");
}
else if (thd->get_stmt_da()->is_set())
{
if (thd->get_stmt_da()->status() != Diagnostics_area::DA_OK)
{
WSREP_WARN("replay ok, thd has error status %d",
thd->get_stmt_da()->status());
}
}
else
{
my_ok(thd);
}
break;
case WSREP_TRX_FAIL:
if (thd->get_stmt_da()->is_sent())
{
WSREP_ERROR("replay failed, thd has reported status");
}
else
{
WSREP_DEBUG("replay failed, rolling back");
//my_error(ER_LOCK_DEADLOCK, MYF(0), "wsrep aborted transaction");
}
thd->wsrep_conflict_state= ABORTED;
wsrep->post_rollback(wsrep, &thd->wsrep_ws_handle);
break;
default:
WSREP_ERROR("trx_replay failed for: %d, schema: %s, query: %s",
rcode,
(thd->db ? thd->db : "(null)"),
thd->query() ? thd->query() : "void");
/* we're now in inconsistent state, must abort */
/* http://bazaar.launchpad.net/~codership/codership-mysql/5.6/revision/3962#sql/wsrep_thd.cc */
mysql_mutex_unlock(&thd->LOCK_wsrep_thd);
unireg_abort(1);
break;
}
wsrep_cleanup_transaction(thd);
mysql_mutex_lock(&LOCK_wsrep_replaying);
wsrep_replaying--;
WSREP_DEBUG("replaying decreased: %d, thd: %lu",
wsrep_replaying, thd->thread_id);
mysql_cond_broadcast(&COND_wsrep_replaying);
mysql_mutex_unlock(&LOCK_wsrep_replaying);
}
}
}
static void wsrep_replication_process(THD *thd)
{
int rcode;
DBUG_ENTER("wsrep_replication_process");
struct wsrep_thd_shadow shadow;
wsrep_prepare_bf_thd(thd, &shadow);
/* From trans_begin() */
thd->variables.option_bits|= OPTION_BEGIN;
thd->server_status|= SERVER_STATUS_IN_TRANS;
rcode = wsrep->recv(wsrep, (void *)thd);
DBUG_PRINT("wsrep",("wsrep_repl returned: %d", rcode));
WSREP_INFO("applier thread exiting (code:%d)", rcode);
switch (rcode) {
case WSREP_OK:
case WSREP_NOT_IMPLEMENTED:
case WSREP_CONN_FAIL:
/* provider does not support slave operations / disconnected from group,
* just close applier thread */
break;
case WSREP_NODE_FAIL:
/* data inconsistency => SST is needed */
/* Note: we cannot just blindly restart replication here,
* SST might require server restart if storage engines must be
* initialized after SST */
WSREP_ERROR("node consistency compromised, aborting");
wsrep_kill_mysql(thd);
break;
case WSREP_WARNING:
case WSREP_TRX_FAIL:
case WSREP_TRX_MISSING:
/* these suggests a bug in provider code */
WSREP_WARN("bad return from recv() call: %d", rcode);
/* fall through to node shutdown */
case WSREP_FATAL:
/* Cluster connectivity is lost.
*
* If applier was killed on purpose (KILL_CONNECTION), we
* avoid mysql shutdown. This is because the killer will then handle
* shutdown processing (or replication restarting)
*/
if (thd->killed != KILL_CONNECTION)
{
wsrep_kill_mysql(thd);
}
break;
}
mysql_mutex_lock(&LOCK_thread_count);
wsrep_close_applier(thd);
mysql_cond_broadcast(&COND_thread_count);
mysql_mutex_unlock(&LOCK_thread_count);
TABLE *tmp;
while ((tmp = thd->temporary_tables))
{
WSREP_WARN("Applier %lu, has temporary tables at exit: %s.%s",
thd->thread_id,
(tmp->s) ? tmp->s->db.str : "void",
(tmp->s) ? tmp->s->table_name.str : "void");
}
wsrep_return_from_bf_mode(thd, &shadow);
DBUG_VOID_RETURN;
}
static bool create_wsrep_THD(wsrep_thd_processor_fun processor)
{
ulong old_wsrep_running_threads= wsrep_running_threads;
pthread_t unused;
mysql_mutex_lock(&LOCK_thread_count);
bool res= pthread_create(&unused, &connection_attrib, start_wsrep_THD,
(void*)processor);
/*
if starting a thread on server startup, wait until the this thread's THD
is fully initialized (otherwise a THD initialization code might
try to access a partially initialized server data structure - MDEV-8208).
*/
if (!mysqld_server_initialized)
while (old_wsrep_running_threads == wsrep_running_threads)
mysql_cond_wait(&COND_thread_count, &LOCK_thread_count);
mysql_mutex_unlock(&LOCK_thread_count);
return res;
}
void wsrep_create_appliers(long threads)
{
if (!wsrep_connected)
{
/* see wsrep_replication_start() for the logic */
if (wsrep_cluster_address && strlen(wsrep_cluster_address) &&
wsrep_provider && strcasecmp(wsrep_provider, "none"))
{
WSREP_ERROR("Trying to launch slave threads before creating "
"connection at '%s'", wsrep_cluster_address);
assert(0);
}
return;
}
long wsrep_threads=0;
while (wsrep_threads++ < threads) {
if (create_wsrep_THD(wsrep_replication_process))
WSREP_WARN("Can't create thread to manage wsrep replication");
}
}
static void wsrep_rollback_process(THD *thd)
{
DBUG_ENTER("wsrep_rollback_process");
mysql_mutex_lock(&LOCK_wsrep_rollback);
wsrep_aborting_thd= NULL;
while (thd->killed == NOT_KILLED) {
thd_proc_info(thd, "wsrep aborter idle");
thd->mysys_var->current_mutex= &LOCK_wsrep_rollback;
thd->mysys_var->current_cond= &COND_wsrep_rollback;
mysql_cond_wait(&COND_wsrep_rollback,&LOCK_wsrep_rollback);
WSREP_DEBUG("WSREP rollback thread wakes for signal");
mysql_mutex_lock(&thd->mysys_var->mutex);
thd_proc_info(thd, "wsrep aborter active");
thd->mysys_var->current_mutex= 0;
thd->mysys_var->current_cond= 0;
mysql_mutex_unlock(&thd->mysys_var->mutex);
/* check for false alarms */
if (!wsrep_aborting_thd)
{
WSREP_DEBUG("WSREP rollback thread has empty abort queue");
}
/* process all entries in the queue */
while (wsrep_aborting_thd) {
THD *aborting;
wsrep_aborting_thd_t next = wsrep_aborting_thd->next;
aborting = wsrep_aborting_thd->aborting_thd;
my_free(wsrep_aborting_thd);
wsrep_aborting_thd= next;
/*
* must release mutex, appliers my want to add more
* aborting thds in our work queue, while we rollback
*/
mysql_mutex_unlock(&LOCK_wsrep_rollback);
mysql_mutex_lock(&aborting->LOCK_wsrep_thd);
if (aborting->wsrep_conflict_state== ABORTED)
{
WSREP_DEBUG("WSREP, thd already aborted: %llu state: %d",
(long long)aborting->real_id,
aborting->wsrep_conflict_state);
mysql_mutex_unlock(&aborting->LOCK_wsrep_thd);
mysql_mutex_lock(&LOCK_wsrep_rollback);
continue;
}
aborting->wsrep_conflict_state= ABORTING;
mysql_mutex_unlock(&aborting->LOCK_wsrep_thd);
set_current_thd(aborting);
aborting->store_globals();
mysql_mutex_lock(&aborting->LOCK_wsrep_thd);
wsrep_client_rollback(aborting);
WSREP_DEBUG("WSREP rollbacker aborted thd: (%lu %llu)",
aborting->thread_id, (long long)aborting->real_id);
mysql_mutex_unlock(&aborting->LOCK_wsrep_thd);
set_current_thd(thd);
thd->store_globals();
mysql_mutex_lock(&LOCK_wsrep_rollback);
}
}
mysql_mutex_unlock(&LOCK_wsrep_rollback);
sql_print_information("WSREP: rollbacker thread exiting");
DBUG_PRINT("wsrep",("wsrep rollbacker thread exiting"));
DBUG_VOID_RETURN;
}
void wsrep_create_rollbacker()
{
if (wsrep_provider && strcasecmp(wsrep_provider, "none"))
{
/* create rollbacker */
if (create_wsrep_THD(wsrep_rollback_process))
WSREP_WARN("Can't create thread to manage wsrep rollback");
}
}
void wsrep_thd_set_PA_safe(void *thd_ptr, my_bool safe)
{
if (thd_ptr)
{
THD* thd = (THD*)thd_ptr;
thd->wsrep_PA_safe = safe;
}
}
enum wsrep_conflict_state wsrep_thd_conflict_state(THD *thd, my_bool sync)
{
enum wsrep_conflict_state state = NO_CONFLICT;
if (thd)
{
if (sync) mysql_mutex_lock(&thd->LOCK_wsrep_thd);
state = thd->wsrep_conflict_state;
if (sync) mysql_mutex_unlock(&thd->LOCK_wsrep_thd);
}
return state;
}
my_bool wsrep_thd_is_wsrep(THD *thd)
{
my_bool status = FALSE;
if (thd)
{
status = (WSREP(thd) && WSREP_PROVIDER_EXISTS);
}
return status;
}
my_bool wsrep_thd_is_BF(THD *thd, my_bool sync)
{
my_bool status = FALSE;
if (thd)
{
// THD can be BF only if provider exists
if (wsrep_thd_is_wsrep(thd))
{
if (sync)
mysql_mutex_lock(&thd->LOCK_wsrep_thd);
status = ((thd->wsrep_exec_mode == REPL_RECV) ||
(thd->wsrep_exec_mode == TOTAL_ORDER));
if (sync)
mysql_mutex_unlock(&thd->LOCK_wsrep_thd);
}
}
return status;
}
extern "C"
my_bool wsrep_thd_is_BF_or_commit(void *thd_ptr, my_bool sync)
{
bool status = FALSE;
if (thd_ptr)
{
THD* thd = (THD*)thd_ptr;
if (sync) mysql_mutex_lock(&thd->LOCK_wsrep_thd);
status = ((thd->wsrep_exec_mode == REPL_RECV) ||
(thd->wsrep_exec_mode == TOTAL_ORDER) ||
(thd->wsrep_exec_mode == LOCAL_COMMIT));
if (sync) mysql_mutex_unlock(&thd->LOCK_wsrep_thd);
}
return status;
}
extern "C"
my_bool wsrep_thd_is_local(void *thd_ptr, my_bool sync)
{
bool status = FALSE;
if (thd_ptr)
{
THD* thd = (THD*)thd_ptr;
if (sync) mysql_mutex_lock(&thd->LOCK_wsrep_thd);
status = (thd->wsrep_exec_mode == LOCAL_STATE);
if (sync) mysql_mutex_unlock(&thd->LOCK_wsrep_thd);
}
return status;
}
int wsrep_abort_thd(void *bf_thd_ptr, void *victim_thd_ptr, my_bool signal)
{
THD *victim_thd = (THD *) victim_thd_ptr;
THD *bf_thd = (THD *) bf_thd_ptr;
DBUG_ENTER("wsrep_abort_thd");
if ( (WSREP(bf_thd) ||
( (WSREP_ON || bf_thd->variables.wsrep_OSU_method == WSREP_OSU_RSU) &&
bf_thd->wsrep_exec_mode == TOTAL_ORDER) ) &&
victim_thd)
{
if ((victim_thd->wsrep_conflict_state == MUST_ABORT) ||
(victim_thd->wsrep_conflict_state == ABORTED) ||
(victim_thd->wsrep_conflict_state == ABORTING))
{
WSREP_DEBUG("wsrep_abort_thd called by %llu with victim %llu already "
"aborted. Ignoring.",
(bf_thd) ? (long long)bf_thd->real_id : 0,
(long long)victim_thd->real_id);
DBUG_RETURN(1);
}
WSREP_DEBUG("wsrep_abort_thd, by: %llu, victim: %llu", (bf_thd) ?
(long long)bf_thd->real_id : 0, (long long)victim_thd->real_id);
ha_abort_transaction(bf_thd, victim_thd, signal);
}
else
{
WSREP_DEBUG("wsrep_abort_thd not effective: %p %p", bf_thd, victim_thd);
}
DBUG_RETURN(1);
}
extern "C"
int wsrep_thd_in_locking_session(void *thd_ptr)
{
if (thd_ptr && ((THD *)thd_ptr)->in_lock_tables) {
return 1;
}
return 0;
}
bool wsrep_thd_has_explicit_locks(THD *thd)
{
assert(thd);
return thd->mdl_context.has_explicit_locks();
}