Refactor DetermineSleepTime() to use milliseconds.

Since we're not using select() anymore, we don't need to bother with
struct timeval.  We can work directly in milliseconds, which the latch
API wants.

Discussion: https://postgr.es/m/CA%2BhUKG%2BZ-HpOj1JsO9eWUP%2Bar7npSVinsC_npxSy%2BjdOMsx%3DGg%40mail.gmail.com

diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index ac0102b4861754a1eb8c9759b745fac8f2a97e06..9cedc1b9f0d50ea414cc8dd24d8de1e619b159ff 100644 (file)
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -1586,7 +1586,7 @@ checkControlFile(void)
 }
 
 /*
- * Determine how long should we let ServerLoop sleep.
+ * Determine how long should we let ServerLoop sleep, in milliseconds.
  *
  * In normal conditions we wait at most one minute, to ensure that the other
  * background tasks handled by ServerLoop get done even when no requests are
@@ -1594,8 +1594,8 @@ checkControlFile(void)
  * we don't actually sleep so that they are quickly serviced.  Other exception
  * cases are as shown in the code.
  */
-static void
-DetermineSleepTime(struct timeval *timeout)
+static int
+DetermineSleepTime(void)
 {
        TimestampTz next_wakeup = 0;
 
@@ -1608,26 +1608,20 @@ DetermineSleepTime(struct timeval *timeout)
        {
                if (AbortStartTime != 0)
                {
+                       int                     seconds;
+
                        /* time left to abort; clamp to 0 in case it already expired */
-                       timeout->tv_sec = SIGKILL_CHILDREN_AFTER_SECS -
+                       seconds = SIGKILL_CHILDREN_AFTER_SECS -
                                (time(NULL) - AbortStartTime);
-                       timeout->tv_sec = Max(timeout->tv_sec, 0);
-                       timeout->tv_usec = 0;
+
+                       return Max(seconds * 1000, 0);
                }
                else
-               {
-                       timeout->tv_sec = 60;
-                       timeout->tv_usec = 0;
-               }
-               return;
+                       return 60 * 1000;
        }
 
        if (StartWorkerNeeded)
-       {
-               timeout->tv_sec = 0;
-               timeout->tv_usec = 0;
-               return;
-       }
+               return 0;
 
        if (HaveCrashedWorker)
        {
@@ -1665,26 +1659,14 @@ DetermineSleepTime(struct timeval *timeout)
 
        if (next_wakeup != 0)
        {
-               long            secs;
-               int                     microsecs;
-
-               TimestampDifference(GetCurrentTimestamp(), next_wakeup,
-                                                       &secs, &microsecs);
-               timeout->tv_sec = secs;
-               timeout->tv_usec = microsecs;
-
-               /* Ensure we don't exceed one minute */
-               if (timeout->tv_sec > 60)
-               {
-                       timeout->tv_sec = 60;
-                       timeout->tv_usec = 0;
-               }
-       }
-       else
-       {
-               timeout->tv_sec = 60;
-               timeout->tv_usec = 0;
+               /* Ensure we don't exceed one minute, or go under 0. */
+               return Max(0,
+                                  Min(60 * 1000,
+                                          TimestampDifferenceMilliseconds(GetCurrentTimestamp(),
+                                                                                                          next_wakeup)));
        }
+
+       return 60 * 1000;
 }
 
 /*
@@ -1743,12 +1725,9 @@ ServerLoop(void)
        for (;;)
        {
                time_t          now;
-               struct timeval timeout;
-
-               DetermineSleepTime(&timeout);
 
                nevents = WaitEventSetWait(pm_wait_set,
-                                                                  timeout.tv_sec * 1000 + timeout.tv_usec / 1000,
+                                                                  DetermineSleepTime(),
                                                                   events,
                                                                   lengthof(events),
                                                                   0 /* postmaster posts no wait_events */ );