commit 5a5f768667736d683bd1555b72d410e32db307a3
author Gabe Black <gabeblack@google.com> Fri Sep 07 15:19:44 2018 -0700
committer Gabe Black <gabeblack@google.com> Tue Oct 09 21:41:30 2018 +0000
tree 51cb753e35212bccb60168f8f96df6534fdf2493
parent 09432ca3cd5372bae3a4f041049ea181ddb7db31

systemc: Track the scheduler status using an enum instead of bools.

The scheduler tracked whether it was paused or stopped with two bools
which are mutually exclusive. It's useful to be able to also check for
some other mutually exclusive states like what phase the scheduler is
currently running.

Rather than adding a bunch of additional bools, this change switches
those mutually exclusive states over to an enum, and adds some methods
to access and maintain that enum.

Change-Id: Ia9696b2853d1b122c1100c9df0e12b018fe9b84b
Reviewed-on: https://gem5-review.googlesource.com/c/12605
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

src/systemc/core/scheduler.cc

diff --git a/src/systemc/core/scheduler.cc b/src/systemc/core/scheduler.cc
index 5348e66..beec87d 100644
--- a/src/systemc/core/scheduler.cc
+++ b/src/systemc/core/scheduler.cc
@@ -46,7 +46,7 @@
     stopEvent(this, false, StopPriority),
     scMain(nullptr), _throwToScMain(nullptr),
     starvationEvent(this, false, StarvationPriority),
-    _started(false), _paused(false), _stopped(false), _stopNow(false),
+    _started(false), _stopNow(false), _status(StatusOther),
     maxTickEvent(this, false, MaxTickPriority),
     _numCycles(0), _changeStamp(0), _current(nullptr), initDone(false),
     runOnce(false), readyList(nullptr)
@@ -123,10 +123,8 @@
         p->ready();
     }
 
-    update();
-
-    while (!deltas.empty())
-        deltas.front()->run();
+    runUpdate();
+    runDelta();
 
     for (auto ets: eventsToSchedule)
         eq->schedule(ets.first, ets.second);
@@ -139,6 +137,8 @@
     }
 
     initDone = true;
+
+    status(StatusOther);
 }
 
 void
@@ -311,23 +311,23 @@
     if (_stopNow)
         return;
 
-    // The update phase.
-    update();
-
-    // The delta phase.
-    while (!deltas.empty())
-        deltas.front()->run();
+    runUpdate();
+    runDelta();
 
     if (!runToTime && starved())
         scheduleStarvationEvent();
 
     if (runOnce)
         schedulePause();
+
+    status(StatusOther);
 }
 
 void
-Scheduler::update()
+Scheduler::runUpdate()
 {
+    status(StatusUpdate);
+
     Channel *channel = updateList.getNext();
     while (channel) {
         channel->popListNode();
@@ -337,9 +337,17 @@
 }
 
 void
+Scheduler::runDelta()
+{
+    status(StatusDelta);
+    while (!deltas.empty())
+        deltas.front()->run();
+}
+
+void
 Scheduler::pause()
 {
-    _paused = true;
+    status(StatusPaused);
     kernel->status(::sc_core::SC_PAUSED);
     runOnce = false;
     if (scMain && !scMain->finished())
@@ -349,7 +357,7 @@
 void
 Scheduler::stop()
 {
-    _stopped = true;
+    status(StatusStopped);
     kernel->stop();
 
     clear();
@@ -367,8 +375,7 @@
     scMain = Fiber::currentFiber();
 
     _started = true;
-    _paused = false;
-    _stopped = false;
+    status(StatusOther);
     runToTime = run_to_time;
 
     maxTick = max_tick;

src/systemc/core/scheduler.hh

diff --git a/src/systemc/core/scheduler.hh b/src/systemc/core/scheduler.hh
index dda483f..7b62388 100644
--- a/src/systemc/core/scheduler.hh
+++ b/src/systemc/core/scheduler.hh
@@ -318,7 +318,10 @@
     }
 
     // Run scheduled channel updates.
-    void update();
+    void runUpdate();
+
+    // Run delta events.
+    void runDelta();
 
     void setScMainFiber(Fiber *sc_main) { scMain = sc_main; }
 
@@ -328,13 +331,29 @@
     void schedulePause();
     void scheduleStop(bool finish_delta);
 
-    bool paused() { return _paused; }
-    bool stopped() { return _stopped; }
+    enum Status
+    {
+        StatusOther = 0,
+        StatusDelta,
+        StatusUpdate,
+        StatusTiming,
+        StatusPaused,
+        StatusStopped
+    };
+
+    bool paused() { return status() == StatusPaused; }
+    bool stopped() { return status() == StatusStopped; }
+    bool inDelta() { return status() == StatusDelta; }
+    bool inUpdate() { return status() == StatusUpdate; }
+    bool inTiming() { return status() == StatusTiming; }
 
     uint64_t changeStamp() { return _changeStamp; }
 
     void throwToScMain(const ::sc_core::sc_report *r=nullptr);
 
+    Status status() { return _status; }
+    void status(Status s) { _status = s; }
+
   private:
     typedef const EventBase::Priority Priority;
     static Priority DefaultPriority = EventBase::Default_Pri;
@@ -395,10 +414,10 @@
     void scheduleStarvationEvent();
 
     bool _started;
-    bool _paused;
-    bool _stopped;
     bool _stopNow;
 
+    Status _status;
+
     Tick maxTick;
     Tick lastReadyTick;
     void
@@ -436,8 +455,12 @@
 inline void
 Scheduler::TimeSlot::process()
 {
+    scheduler.status(StatusTiming);
+
     while (!events.empty())
         events.front()->run();
+
+    scheduler.status(StatusOther);
     scheduler.completeTimeSlot(this);
 }