index 74d90e6f8871b302b7e3c8762b0718843d6e8bbe..4543c5c5032309bb3888c4d68cbb3127fbda3361 100644 (file)
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/postmaster/postmaster.c,v 1.538 2007年08月03日 20:06:50 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/postmaster/postmaster.c,v 1.539 2007年08月04日 03:15:49 tgl Exp $
*
* NOTES
*
@@ -230,6 +230,7 @@ static volatile sig_atomic_t start_autovac_launcher = false;
* backend from the postmaster to that backend (via fork).
*/
static unsigned int random_seed = 0;
+static struct timeval random_start_time;
extern char *optarg;
extern int optind,
* Remember postmaster startup time
*/
PgStartTime = GetCurrentTimestamp();
+ /* PostmasterRandom wants its own copy */
+ gettimeofday(&random_start_time, NULL);
/*
* We're ready to rock and roll...
int nSockets;
time_t now,
last_touch_time;
- struct timeval earlier,
- later;
- gettimeofday(&earlier, NULL);
last_touch_time = time(NULL);
nSockets = initMasks(&readmask);
*/
if (selres > 0)
{
- /*
- * Select a random seed at the time of first receiving a request.
- */
- while (random_seed == 0)
- {
- gettimeofday(&later, NULL);
-
- /*
- * We are not sure how much precision is in tv_usec, so we
- * swap the high and low 16 bits of 'later' and XOR them with
- * 'earlier'. On the off chance that the result is 0, we loop
- * until it isn't.
- */
- random_seed = earlier.tv_usec ^
- ((later.tv_usec << 16) |
- ((later.tv_usec >> 16) & 0xffff));
- }
-
for (i = 0; i < MAXLISTEN; i++)
{
if (ListenSocket[i] == -1)
* a new random sequence in the random() library function.
*/
random_seed = 0;
+ random_start_time.tv_usec = 0;
/* slightly hacky way to get integer microseconds part of timestamptz */
TimestampDifference(0, port->SessionStartTime, &secs, &usecs);
srandom((unsigned int) (MyProcPid ^ usecs));
static long
PostmasterRandom(void)
{
- static bool initialized = false;
-
- if (!initialized)
+ /*
+ * Select a random seed at the time of first receiving a request.
+ */
+ if (random_seed == 0)
{
- Assert(random_seed != 0);
+ do
+ {
+ struct timeval random_stop_time;
+
+ gettimeofday(&random_stop_time, NULL);
+ /*
+ * We are not sure how much precision is in tv_usec, so we swap
+ * the high and low 16 bits of 'random_stop_time' and XOR them
+ * with 'random_start_time'. On the off chance that the result is
+ * 0, we loop until it isn't.
+ */
+ random_seed = random_start_time.tv_usec ^
+ ((random_stop_time.tv_usec << 16) |
+ ((random_stop_time.tv_usec >> 16) & 0xffff));
+ }
+ while (random_seed == 0);
+
srandom(random_seed);
- initialized = true;
}
return random();