diff options
| -rw-r--r-- | src/backend/postmaster/postmaster.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c index 688f462e7d0..981a058522f 100644 --- a/src/backend/postmaster/postmaster.c +++ b/src/backend/postmaster/postmaster.c @@ -2525,8 +2525,16 @@ InitProcessGlobals(void) random_start_time.tv_usec = 0; #endif - /* Set a different seed for random() in every backend. */ - srandom((unsigned int) MyProcPid ^ (unsigned int) MyStartTimestamp); + /* + * Set a different seed for random() in every backend. Since PIDs and + * timestamps tend to change more frequently in their least significant + * bits, shift the timestamp left to allow a larger total number of seeds + * in a given time period. Since that would leave only 20 bits of the + * timestamp that cycle every ~1 second, also mix in some higher bits. + */ + srandom(((unsigned int) MyProcPid) ^ + ((unsigned int) MyStartTimestamp << 12) ^ + ((unsigned int) MyStartTimestamp >> 20)); } |