systemc: Implement general and VCD trace support.

This doesn't include WIF trace support, but does make allowances for
adding it in the future.

Change-Id: Ifb62f40a7d8a13e94463930a44ac4b1cf41e3009
Reviewed-on: https://gem5-review.googlesource.com/c/12826
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

2 files changed, 40 insertions, 2 deletions

diff --git a/src/systemc/core/scheduler.cc b/src/systemc/core/scheduler.cc
index ae1aa899f..d79abb251 100644
--- a/src/systemc/core/scheduler.cc
+++ b/src/systemc/core/scheduler.cc
@@ -36,6 +36,7 @@
 #include "systemc/ext/core/sc_main.hh"
 #include "systemc/ext/utils/sc_report.hh"
 #include "systemc/ext/utils/sc_report_handler.hh"
+#include "systemc/utils/tracefile.hh"
 
 namespace sc_gem5
 {
@@ -48,8 +49,8 @@ Scheduler::Scheduler() :
     starvationEvent(this, false, StarvationPriority),
     _elaborationDone(false), _started(false), _stopNow(false),
     _status(StatusOther), maxTickEvent(this, false, MaxTickPriority),
-    _numCycles(0), _changeStamp(0), _current(nullptr), initDone(false),
-    runOnce(false)
+    timeAdvancesEvent(this, false, TimeAdvancesPriority), _numCycles(0),
+    _changeStamp(0), _current(nullptr), initDone(false), runOnce(false)
 {}
 
 Scheduler::~Scheduler()
@@ -86,6 +87,8 @@ Scheduler::clear()
         deschedule(&starvationEvent);
     if (maxTickEvent.scheduled())
         deschedule(&maxTickEvent);
+    if (timeAdvancesEvent.scheduled())
+        deschedule(&timeAdvancesEvent);
 
     Process *p;
     while ((p = initList.getNext()))
@@ -134,6 +137,8 @@ Scheduler::initPhase()
     initDone = true;
 
     status(StatusOther);
+
+    scheduleTimeAdvancesEvent();
 }
 
 void
@@ -263,10 +268,13 @@ Scheduler::scheduleStarvationEvent()
 void
 Scheduler::runReady()
 {
+    scheduleTimeAdvancesEvent();
+
     bool empty = readyListMethods.empty() && readyListThreads.empty();
     lastReadyTick = getCurTick();
 
     // The evaluation phase.
+    status(StatusEvaluate);
     do {
         yield();
     } while (getNextReady());
@@ -282,6 +290,8 @@ Scheduler::runReady()
     }
 
     runUpdate();
+    if (!traceFiles.empty())
+        trace(true);
     runDelta();
 
     if (!runToTime && starved())
@@ -367,6 +377,7 @@ Scheduler::start(Tick max_tick, bool run_to_time)
     }
 
     schedule(&maxTickEvent, maxTick);
+    scheduleTimeAdvancesEvent();
 
     // Return to gem5 to let it run events, etc.
     Fiber::primaryFiber()->run();
@@ -429,6 +440,13 @@ Scheduler::scheduleStop(bool finish_delta)
     schedule(&stopEvent);
 }
 
+void
+Scheduler::trace(bool delta)
+{
+    for (auto tf: traceFiles)
+        tf->trace(delta);
+}
+
 Scheduler scheduler;
 
 namespace {
diff --git a/src/systemc/core/scheduler.hh b/src/systemc/core/scheduler.hh
index 8015260a3..ebe15462c 100644
--- a/src/systemc/core/scheduler.hh
+++ b/src/systemc/core/scheduler.hh
@@ -48,6 +48,8 @@ class Fiber;
 namespace sc_gem5
 {
 
+class TraceFile;
+
 typedef NodeList<Process> ProcessList;
 typedef NodeList<Channel> ChannelList;
 
@@ -280,6 +282,7 @@ class Scheduler
         timeSlots.erase(timeSlots.begin());
         if (!runToTime && starved())
             scheduleStarvationEvent();
+        scheduleTimeAdvancesEvent();
     }
 
     // Pending activity ignores gem5 activity, much like how a systemc
@@ -357,6 +360,9 @@ class Scheduler
     Status status() { return _status; }
     void status(Status s) { _status = s; }
 
+    void registerTraceFile(TraceFile *tf) { traceFiles.insert(tf); }
+    void unregisterTraceFile(TraceFile *tf) { traceFiles.erase(tf); }
+
   private:
     typedef const EventBase::Priority Priority;
     static Priority DefaultPriority = EventBase::Default_Pri;
@@ -366,6 +372,7 @@ class Scheduler
     static Priority MaxTickPriority = DefaultPriority + 2;
     static Priority ReadyPriority = DefaultPriority + 3;
     static Priority StarvationPriority = ReadyPriority;
+    static Priority TimeAdvancesPriority = EventBase::Maximum_Pri;
 
     EventQueue *eq;
 
@@ -440,6 +447,15 @@ class Scheduler
     }
     EventWrapper<Scheduler, &Scheduler::maxTickFunc> maxTickEvent;
 
+    void timeAdvances() { trace(false); }
+    EventWrapper<Scheduler, &Scheduler::timeAdvances> timeAdvancesEvent;
+    void
+    scheduleTimeAdvancesEvent()
+    {
+        if (!traceFiles.empty() && !timeAdvancesEvent.scheduled())
+            schedule(&timeAdvancesEvent);
+    }
+
     uint64_t _numCycles;
     uint64_t _changeStamp;
 
@@ -457,6 +473,10 @@ class Scheduler
     ChannelList updateList;
 
     std::map<::Event *, Tick> eventsToSchedule;
+
+    std::set<TraceFile *> traceFiles;
+
+    void trace(bool delta);
 };
 
 extern Scheduler scheduler;