Avoid calling poll or gettimeofday for 1000 line bursts.

1 files changed, 31 insertions, 24 deletions

diff --git a/pw.c b/pw.c
index 1dc2a40..6ea1407 100644
--- a/pw.c
+++ b/pw.c
@@ -396,7 +396,9 @@ int main(int argc, char **argv)
   if (fcntl(fd, F_SETFL, O_NONBLOCK) < 0)
     panic("unable to set stdin nonblocking");
 
-  for (unsigned stat = stat_dirty, hpos = 0, kbd_state = kbd_cmd, lasttime = ~0U;
+  for (unsigned stat = stat_dirty, hpos = 0,
+                kbd_state = kbd_cmd, lasttime = ~0U,
+                work = 1000;
        kbd_state != kbd_exit ;)
   {
     int force = 0, nfds = 2, pollms = poll_interval;
@@ -405,24 +407,6 @@ int main(int argc, char **argv)
       { .fd = fd, .events = POLLIN | POLLHUP | POLLERR },
     };
 
-    if (stat & stat_trgrd)
-      force = 1;
-
-    if (!force)
-    {
-      struct timeval tv;
-      unsigned now;
-
-      gettimeofday(&tv, NULL);
-      now = (((unsigned) tv.tv_sec)%1000000)*1000 + tv.tv_usec/1000;
-      if (lasttime == ~0U || now - lasttime > (unsigned) long_interval) {
-        if ((stat & stat_dirty) && nlines == maxlines)
-          force = 1;
-        lasttime = now;
-        stat &= ~stat_dirty;
-      }
-    }
-
     if ((stat & stat_eof) == 0) {
       int ch;
       while ((ch = getc(stdin)) != EOF && ch != '\n')
@@ -470,16 +454,39 @@ int main(int argc, char **argv)
       nfds = 1;
     }
 
-    if (force) {
-      redraw(circbuf, nlines, hpos, columns, stat, curcmd);
-      stat &= ~(stat_dirty | stat_trgrd);
-    }
-
     if ((stat & stat_eof))
       pollms = -1;
     else if (nfds < 2)
       pollms = 0;
 
+    if ((stat & (stat_trgrd | stat_susp)) == stat_trgrd)
+      force = 1;
+
+    if (pollms == 0 && !force && work-- > 0)
+      continue;
+
+    work = 1000;
+
+    if (!force)
+    {
+      struct timeval tv;
+      unsigned now;
+
+      gettimeofday(&tv, NULL);
+      now = (((unsigned) tv.tv_sec)%1000000)*1000 + tv.tv_usec/1000;
+      if (lasttime == ~0U || now - lasttime > (unsigned) long_interval) {
+        if ((stat & stat_dirty) && nlines == maxlines)
+          force = 1;
+        lasttime = now;
+        stat &= ~stat_dirty;
+      }
+    }
+
+    if (force) {
+      redraw(circbuf, nlines, hpos, columns, stat, curcmd);
+      stat &= ~(stat_dirty | stat_trgrd);
+    }
+
     if (poll(pe, nfds, pollms) <= 0) {
       if (pollms) {
         if ((stat & stat_dirty) && nlines == maxlines) {