mariadb/unittest/sql/my_apc-t.cc
Kristian Nielsen 2a4c573339 MDEV-32728: Wrong mutex usage 'LOCK_thd_data' and 'wait_mutex'
Checking for kill with thd_kill_level() or check_killed() runs apc
requests, which takes the LOCK_thd_kill mutex. But this is dangerous,
as checking for kill needs to be called while holding many different
mutexes, and can lead to cyclic mutex dependency and deadlock.

But running apc is only "best effort", so skip running the apc if the
LOCK_thd_kill is not available. The apc will then be run on next check
of kill signal.

Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
2023-11-08 14:50:43 +01:00

229 lines
5.2 KiB
C++

/*
Copyright (c) 2012, Monty Program Ab
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 02110-1335 USA */
/*
This file does standalone APC system tests.
*/
#include <my_global.h>
#include <my_pthread.h>
#include <my_sys.h>
#include <stdio.h>
#include <tap.h>
/*
A fake THD with enter_cond/exit_cond and some other members.
*/
PSI_stage_info stage_show_explain;
class THD
{
mysql_mutex_t* thd_mutex;
public:
bool killed;
THD() : killed(FALSE) {}
inline const char* ENTER_COND(mysql_cond_t *cond, mysql_mutex_t* mutex,
PSI_stage_info*, PSI_stage_info*)
{
mysql_mutex_assert_owner(mutex);
thd_mutex= mutex;
return NULL;
}
inline void EXIT_COND(PSI_stage_info*)
{
mysql_mutex_unlock(thd_mutex);
}
};
#include "../sql/my_apc.h"
#define MY_APC_STANDALONE 1
#include "../sql/my_apc.cc"
volatile bool started= FALSE;
volatile bool service_should_exit= FALSE;
volatile bool requestors_should_exit=FALSE;
/* Counters for APC calls */
int apcs_served= 0;
int apcs_missed=0;
int apcs_timed_out=0;
mysql_mutex_t apc_counters_mutex;
inline void increment_counter(int *var)
{
mysql_mutex_lock(&apc_counters_mutex);
*var= *var+1;
mysql_mutex_unlock(&apc_counters_mutex);
}
volatile bool have_errors= false;
Apc_target apc_target;
mysql_mutex_t target_mutex;
int int_rand(int size)
{
return (int) (0.5 + ((double)rand() / RAND_MAX) * size);
}
/*
APC target thread (the one that will serve the APC requests). We will have
one target.
*/
void *test_apc_service_thread(void *ptr)
{
my_thread_init();
mysql_mutex_init(0, &target_mutex, MY_MUTEX_INIT_FAST);
apc_target.init(&target_mutex);
apc_target.enable();
started= TRUE;
diag("test_apc_service_thread started");
while (!service_should_exit)
{
//apc_target.disable();
my_sleep(10000);
//apc_target.enable();
for (int i = 0; i < 10 && !service_should_exit; i++)
{
apc_target.process_apc_requests(true);
my_sleep(int_rand(30));
}
}
apc_target.disable();
apc_target.destroy();
mysql_mutex_destroy(&target_mutex);
my_thread_end();
pthread_exit(0);
return NULL;
}
/*
One APC request (to write 'value' into *where_to)
*/
class Apc_order : public Apc_target::Apc_call
{
public:
int value; // The value
int *where_to; // Where to write it
Apc_order(int a, int *b) : value(a), where_to(b) {}
void call_in_target_thread()
{
my_sleep(int_rand(1000));
*where_to = value;
increment_counter(&apcs_served);
}
};
/*
APC requestor thread. It makes APC requests, and checks if they were actually
executed.
*/
void *test_apc_requestor_thread(void *ptr)
{
my_thread_init();
diag("test_apc_requestor_thread started");
THD my_thd;
while (!requestors_should_exit)
{
int dst_value= 0;
int src_value= int_rand(4*1000*100);
/* Create an APC to do "dst_value= src_value" assignment */
Apc_order apc_order(src_value, &dst_value);
bool timed_out;
mysql_mutex_lock(&target_mutex);
bool res= apc_target.make_apc_call(&my_thd, &apc_order, 60, &timed_out);
if (res)
{
if (timed_out)
increment_counter(&apcs_timed_out);
else
increment_counter(&apcs_missed);
if (dst_value != 0)
{
diag("APC was done even though return value says it wasnt!");
have_errors= true;
}
}
else
{
if (dst_value != src_value)
{
diag("APC was not done even though return value says it was!");
have_errors= true;
}
}
//my_sleep(300);
}
diag("test_apc_requestor_thread exiting");
my_thread_end();
return NULL;
}
/* Number of APC requestor threads */
const int N_THREADS=23;
int main(int args, char **argv)
{
pthread_t service_thr;
pthread_t request_thr[N_THREADS];
int i;
my_thread_global_init();
mysql_mutex_init(0, &apc_counters_mutex, MY_MUTEX_INIT_FAST);
plan(1);
diag("Testing APC delivery and execution");
pthread_create(&service_thr, NULL, test_apc_service_thread, (void*)NULL);
while (!started)
my_sleep(1000);
for (i = 0; i < N_THREADS; i++)
pthread_create(&request_thr[i], NULL, test_apc_requestor_thread, (void*)NULL);
for (i = 0; i < 15; i++)
{
my_sleep(500*1000);
diag("%d APCs served %d missed", apcs_served, apcs_missed);
}
diag("Shutting down requestors");
requestors_should_exit= TRUE;
for (i = 0; i < N_THREADS; i++)
pthread_join(request_thr[i], NULL);
diag("Shutting down service");
service_should_exit= TRUE;
pthread_join(service_thr, NULL);
mysql_mutex_destroy(&apc_counters_mutex);
diag("Done");
my_thread_end();
my_thread_global_end();
ok1(!have_errors);
return exit_status();
}