From: Gabe Black <gabeblack@google.com>
Date: Sun, 26 Aug 2018 22:34:31 +0000 (-0700)
Subject: systemc: Fix some issues with starvation checks.
X-Git-Tag: v19.0.0.0~1723
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=9b6119a6a31f8597eebdc8bb469fd9f407ffa5e4;p=gem5.git

systemc: Fix some issues with starvation checks.

Make sure we check for starvation after timed notifications and at the
very end of delta cycles (after delta notifications, not before). Also
reverse the order of starvation checks (whether they apply at all, then
if they're satisfied) to make those checks faster. Checking a bool
is a lot easier than checking if a bunch of other structures are
empty.

Change-Id: I514ff219909823f1f424fde69856d6b510655188
Reviewed-on: https://gem5-review.googlesource.com/12268
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>
---

diff --git a/src/systemc/core/scheduler.cc b/src/systemc/core/scheduler.cc
index c84aa9a46..46053b40f 100644
--- a/src/systemc/core/scheduler.cc
+++ b/src/systemc/core/scheduler.cc
@@ -124,7 +124,7 @@ Scheduler::initPhase()
     eventsToSchedule.clear();
 
     if (_started) {
-        if (starved() && !runToTime)
+        if (!runToTime && starved())
             scheduleStarvationEvent();
         kernel->status(::sc_core::SC_RUNNING);
     }
@@ -244,14 +244,14 @@ Scheduler::runReady()
     // The update phase.
     update();
 
-    if (starved() && !runToTime)
-        scheduleStarvationEvent();
-
     // The delta phase.
     for (auto &e: deltas)
         e->run();
     deltas.clear();
 
+    if (!runToTime && starved())
+        scheduleStarvationEvent();
+
     if (runOnce)
         schedulePause();
 }
@@ -303,7 +303,7 @@ Scheduler::start(Tick max_tick, bool run_to_time)
     maxTick = max_tick;
 
     if (initDone) {
-        if (starved() && !runToTime)
+        if (!runToTime && starved())
             scheduleStarvationEvent();
         kernel->status(::sc_core::SC_RUNNING);
     }
diff --git a/src/systemc/core/scheduler.hh b/src/systemc/core/scheduler.hh
index 3068a0aaa..ff8434bef 100644
--- a/src/systemc/core/scheduler.hh
+++ b/src/systemc/core/scheduler.hh
@@ -266,6 +266,8 @@ class Scheduler
     {
         assert(ts == timeSlots.begin()->second);
         timeSlots.erase(timeSlots.begin());
+        if (!runToTime && starved())
+            scheduleStarvationEvent();
     }
 
     // Pending activity ignores gem5 activity, much like how a systemc