diff options
| -rw-r--r-- | contrib/pgbench/pgbench.c | 20 |
1 files changed, 16 insertions, 4 deletions
diff --git a/contrib/pgbench/pgbench.c b/contrib/pgbench/pgbench.c index d41a87cfea8..b5520754e4a 100644 --- a/contrib/pgbench/pgbench.c +++ b/contrib/pgbench/pgbench.c @@ -4,7 +4,7 @@ * 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; * @@ -1916,7 +1916,7 @@ main(int argc, char **argv) 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: @@ -2201,6 +2201,7 @@ pthread_create(pthread_t *thread, { fork_pthread *th; void *ret; + instr_time start_time; th = (fork_pthread *) malloc(sizeof(fork_pthread)); pipe(th->pipes); @@ -2211,20 +2212,31 @@ pthread_create(pthread_t *thread, 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]); |