* A simple benchmark program for PostgreSQL
* Originally written by Tatsuo Ishii and enhanced by many contributors.
*
- * $PostgreSQL: pgsql/contrib/pgbench/pgbench.c,v 1.91 2009/09/10 13:59:57 ishii Exp $
+ * $PostgreSQL: pgsql/contrib/pgbench/pgbench.c,v 1.92 2009/12/11 21:50:06 tgl Exp $
* Copyright (c) 2000-2009, PostgreSQL Global Development Group
* ALL RIGHTS RESERVED;
*
INSTR_TIME_SET_CURRENT(start_time);
srandom((unsigned int) INSTR_TIME_GET_MICROSEC(start_time));
- /* process bultin SQL scripts */
+ /* process builtin SQL scripts */
switch (ttype)
{
case 0:
{
fork_pthread *th;
void *ret;
+ instr_time start_time;
th = (fork_pthread *) malloc(sizeof(fork_pthread));
pipe(th->pipes);
free(th);
return errno;
}
- if (th->pid != 0) /* parent process */
+ if (th->pid != 0) /* in parent process */
{
close(th->pipes[1]);
*thread = th;
return 0;
}
- /* child process */
+ /* in child process */
close(th->pipes[0]);
/* set alarm again because the child does not inherit timers */
if (duration > 0)
setalarm(duration);
+ /*
+ * Set a different random seed in each child process. Otherwise they
+ * all inherit the parent's state and generate the same "random"
+ * sequence. (In the threaded case, the different threads will obtain
+ * subsets of the output of a single random() sequence, which should be
+ * okay for our purposes.)
+ */
+ INSTR_TIME_SET_CURRENT(start_time);
+ srandom(((unsigned int) INSTR_TIME_GET_MICROSEC(start_time)) +
+ ((unsigned int) getpid()));
+
ret = start_routine(arg);
write(th->pipes[1], ret, sizeof(TResult));
close(th->pipes[1]);