The following bug has been logged online:
Bug reference: 1569
Logged by: Gavin Scott
Email address: [EMAIL PROTECTED]
PostgreSQL version: 8.0.1
Operating system: Fedora Core 3
Description: Threads don't see ecpg default connection
Details:
When using postgresql 8.0 compiled with --enable-thread-safety, new threads
no longer see the default ecpg connection. That was not the case in 7.4.x
compiled with or without --enable-thread-safety.
TEST CASE
The program at the end of this mail sets up a database table named
"dbthreadtest" in the default database. It then spawns 5 threads which each
do a select from that table using the default connection.
If the program is saved as dbthreadtest.pgc, compile with:
ecpg -t -o dbthreadtest.c dbthreadtest.pgc
gcc -Wall -o dbthreadtest dbthreadtest.c -lecpg -lpthread
Results under 7.4.x / 8.0 without --enable-thread-safety:
[EMAIL PROTECTED] protocol_lib]$ psql --version
psql (PostgreSQL) 7.4.7
contains support for command-line editing
[EMAIL PROTECTED] protocol_lib]$ ./dbthreadtest
got id = 1
got id = 1
got id = 1
got id = 1
got id = 1
Results under 8.0 with --enable-thread-safety:
[EMAIL PROTECTED] protocol_lib]$ psql --version
psql (PostgreSQL) 8.0.1
contains support for command-line editing
[EMAIL PROTECTED] protocol_lib]$ ./dbthreadtest
'No such connection NULL in line 76.', sqlcode = -220 select id
TEST PROGRAM
/* -*-C-*- */
#include <stdlib.h>
#include <pthread.h>
#define CHECK_SQL(fmt, args...) \
do \
{ \
if (sqlca.sqlcode != ECPG_NO_ERROR) \
{ \
fprintf (stderr, "'%s', sqlcode = %ld " fmt "\n", \
sqlca.sqlerrm.sqlerrmc, \
sqlca.sqlcode, ## args); \
exit (1); \
} \
} \
while (0)
#define FATAL(fmt, args...) \
do \
{ \
fprintf (stderr, fmt "\n", ## args); \
exit (1); \
} \
while (0)
pthread_mutex_t global_lock;
pthread_t global_threads[5];
void
setup_db ()
{
exec sql begin declare section;
const char *_user;
exec sql end declare section;
pthread_mutex_lock (&global_lock);
_user = getenv ("LOGNAME");
exec sql connect to :_user;
CHECK_SQL ("connect");
exec sql create table dbthreadtest (id int);
CHECK_SQL ("create dbthreadtest");
exec sql insert into dbthreadtest (id) values (1);
CHECK_SQL ("insert 1");
pthread_mutex_unlock (&global_lock);
}
void
teardown_db ()
{
pthread_mutex_lock (&global_lock);
exec sql drop table dbthreadtest;
CHECK_SQL ("drop dbthreadtest");
exec sql disconnect;
CHECK_SQL ("disconnect");
pthread_mutex_unlock (&global_lock);
}
void *query_db (void *ignorep)
{
exec sql begin declare section;
int _id;
exec sql end declare section;
pthread_mutex_lock (&global_lock);
exec sql select id into :_id from dbthreadtest;
CHECK_SQL ("select id");
fprintf (stdout, "got id = %d\n", _id);
pthread_mutex_unlock (&global_lock);
return NULL;
}
int
main ()
{
int i;
pthread_mutex_init (&global_lock, NULL);
setup_db ();
for (i = 0; i < sizeof (global_threads) / sizeof (global_threads[0]);
++i)
{
if (pthread_create (&global_threads[i], NULL, query_db, NULL))
FATAL ("pthread_create %d failed", i);
}
for (i = 0; i < sizeof (global_threads) / sizeof (global_threads[0]);
++i)
{
if (pthread_join (global_threads[i], NULL))
FATAL ("pthread_join %d failed", i);
}
teardown_db ();
return 0;
}
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