Delay for loadavg after SIGCONT, bug #476104

diff --git a/pym/_emerge/Scheduler.py b/pym/_emerge/Scheduler.py
index 94d3d3f529b2661278cc4ee0d2447179fe43e7de..5cb4128b37a07d9696f5b5fa3aab339367a11870 100644 (file)
--- a/pym/_emerge/Scheduler.py
+++ b/pym/_emerge/Scheduler.py
@@ -251,6 +251,12 @@ class Scheduler(PollScheduler):
                self._job_delay_max = 5
                self._previous_job_start_time = None
 
+               # The load average takes some time to respond when after
+               # a SIGSTOP/SIGCONT cycle, so delay scheduling for some
+               # time after SIGCONT is received.
+               self._sigcont_delay = 5
+               self._sigcont_time = None
+
                # This is used to memoize the _choose_pkg() result when
                # no packages can be chosen until one of the existing
                # jobs completes.
@@ -1005,6 +1011,8 @@ class Scheduler(PollScheduler):
 
                        earlier_sigint_handler = signal.signal(signal.SIGINT, sighandler)
                        earlier_sigterm_handler = signal.signal(signal.SIGTERM, sighandler)
+                       earlier_sigcont_handler = \
+                               signal.signal(signal.SIGCONT, self._sigcont_handler)
 
                        try:
                                rval = self._merge()
@@ -1018,6 +1026,10 @@ class Scheduler(PollScheduler):
                                        signal.signal(signal.SIGTERM, earlier_sigterm_handler)
                                else:
                                        signal.signal(signal.SIGTERM, signal.SIG_DFL)
+                               if earlier_sigcont_handler is not None:
+                                       signal.signal(signal.SIGCONT, earlier_sigcont_handler)
+                               else:
+                                       signal.signal(signal.SIGCONT, signal.SIG_DFL)
 
                        if received_signal:
                                sys.exit(received_signal[0])
@@ -1579,6 +1591,9 @@ class Scheduler(PollScheduler):
                                not self._task_queues.merge)):
                                break
 
+       def _sigcont_handler(self, signum, frame):
+               self._sigcont_time = time.time()
+
        def _job_delay(self):
                """
                @rtype: bool
@@ -1588,6 +1603,23 @@ class Scheduler(PollScheduler):
                if self._jobs and self._max_load is not None:
 
                        current_time = time.time()
+
+                       if self._sigcont_time is not None:
+
+                               elapsed_seconds = current_time - self._sigcont_time
+                               # elapsed_seconds < 0 means the system clock has been adjusted
+                               if elapsed_seconds > 0 and \
+                                       elapsed_seconds < self._sigcont_delay:
+                                       self._event_loop.timeout_add(
+                                               1000 * (self._sigcont_delay - elapsed_seconds),
+                                               self._schedule_once)
+                                       return True
+
+                               # Only set this to None after the delay has expired,
+                               # since this method may be called again before the
+                               # delay has expired.
+                               self._sigcont_time = None
+
                        try:
                                avg1, avg5, avg15 = getloadavg()
                        except OSError: