Use the new TimestampDifferenceExceeds API instead of timestamp_cmp_internal

and TimestampDifference, to make coding clearer.  I think this should also fix
the failure to start workers in platforms with low resolution timers, as
reported by Itagaki Takahiro.

diff --git a/src/backend/postmaster/autovacuum.c b/src/backend/postmaster/autovacuum.c
index 59128212d5ae02a539dd5ad2b8aaed04083f0fc7..c80979850427d56e9aef252952c36a89898b39b0 100644 (file)
--- a/src/backend/postmaster/autovacuum.c
+++ b/src/backend/postmaster/autovacuum.c
@@ -10,7 +10,7 @@
  *
  *
  * IDENTIFICATION
- *   $PostgreSQL: pgsql/src/backend/postmaster/autovacuum.c,v 1.43 2007/05/02 15:47:14 alvherre Exp $
+ *   $PostgreSQL: pgsql/src/backend/postmaster/autovacuum.c,v 1.44 2007/05/02 18:27:57 alvherre Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -549,8 +549,6 @@ AutoVacLauncherMain(int argc, char *argv[])
 
        if (can_launch && AutoVacuumShmem->av_startingWorker != INVALID_OFFSET)
        {
-           long    secs;
-           int     usecs;
            WorkerInfo worker = (WorkerInfo) MAKE_PTR(AutoVacuumShmem->av_startingWorker);
 
            if (current_time == 0)
@@ -566,11 +564,8 @@ AutoVacLauncherMain(int argc, char *argv[])
             * startingWorker pointer before trying to connect; only low-level
             * problems, like fork() failure, can get us here.
             */
-           TimestampDifference(worker->wi_launchtime, current_time,
-                               &secs, &usecs);
-
-           /* ignore microseconds, as they cannot make any difference */
-           if (secs > autovacuum_naptime)
+           if (TimestampDifferenceExceeds(worker->wi_launchtime, current_time,
+                                          autovacuum_naptime * 1000))
            {
                LWLockRelease(AutovacuumLock);
                LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
@@ -618,13 +613,13 @@ AutoVacLauncherMain(int argc, char *argv[])
            if (elem != NULL)
            {
                avl_dbase *avdb = DLE_VAL(elem);
-               long    secs;
-               int     usecs;
-
-               TimestampDifference(current_time, avdb->adl_next_worker, &secs, &usecs);
 
-               /* do we have to start a worker? */
-               if (secs <= 0 && usecs <= 0)
+               /*
+                * launch a worker if next_worker is right now or it is in the
+                * past
+                */
+               if (TimestampDifferenceExceeds(avdb->adl_next_worker,
+                                              current_time, 0))
                    launch_worker(current_time);
            }
            else
@@ -1037,22 +1032,15 @@ do_start_worker(void)
 
            if (dbp->adl_datid == tmp->adw_datid)
            {
-               TimestampTz     curr_plus_naptime;
-               TimestampTz     next = dbp->adl_next_worker;
-               
-               curr_plus_naptime =
-                   TimestampTzPlusMilliseconds(current_time,
-                                               autovacuum_naptime * 1000);
-
                /*
-                * What we want here if to skip if next_worker falls between
+                * Skip this database if its next_worker value falls between
                 * the current time and the current time plus naptime.
                 */
-               if (timestamp_cmp_internal(current_time, next) > 0)
-                   skipit = false;
-               else if (timestamp_cmp_internal(next, curr_plus_naptime) > 0)
-                   skipit = false;
-               else
+               if (TimestampDifferenceExceeds(current_time,
+                                              dbp->adl_next_worker, 0) &&
+                   !TimestampDifferenceExceeds(current_time,
+                                               dbp->adl_next_worker,
+                                               autovacuum_naptime * 1000))
                    skipit = true;
 
                break;