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 5912821..c809798 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;