Fix stats reset

make SIGUSR2 dump and reset stats
Make resetting time work

base/statistics.cc:
    Fix statistics reset so that it works again, and correctly
    reset bins as well.  (The old code wouldn't reset if you didn't
    have any bins, and then would actually only reset the first
    bin)
cpu/simple_cpu/simple_cpu.cc:
cpu/simple_cpu/simple_cpu.hh:
    convert idleCycles/idleFraction into a single Average stat
    to make reset work more simply
sim/main.cc:
    handle SIGUSR2 to dump and reset stats
    (SIGUSR1 only dumps them)
sim/sim_time.cc:
sim/sim_time.hh:
    Add support for resetting the time

--HG--
extra : convert_revision : ea43e03c50c0a4bb826dc0842a8c4fa1a9289e0a

6 files changed, 58 insertions, 31 deletions

diff --git a/base/statistics.cc b/base/statistics.cc
index 5f21e4de7..1ffbeb690 100644
--- a/base/statistics.cc
+++ b/base/statistics.cc
@@ -265,19 +265,27 @@ Database::check()
 void
 Database::reset()
 {
-    list<GenBin *>::iterator bi = bins.begin();
-    list<GenBin *>::iterator be = bins.end();
     list_t::iterator i = allStats.begin();
     list_t::iterator end = allStats.end();
-
-   while (bi != be) {
-       (*bi)->activate();
-
-       while (i != end) {
-        (*i)->reset();
+    while (i != end) {
+        Stat *stat = *i;
+        stat->reset();
         ++i;
-       }
-       ++bi;
+    }
+
+    list<GenBin *>::iterator bi = bins.begin();
+    list<GenBin *>::iterator be = bins.end();
+    while (bi != be) {
+        GenBin *bin = *bi;
+        bin->activate();
+
+        i = allStats.begin();
+        while (i != end) {
+            Stat *stat = *i;
+            stat->reset();
+            ++i;
+        }
+        ++bi;
     }
 }
 
@@ -736,7 +744,7 @@ VectorDisplay(std::ostream &stream,
                         _pdf = vec[i] / _total;
                         _cdf += _pdf;
                     } else {
-                        _pdf = _cdf = 0.0;
+                        _pdf = _cdf = NAN;
                     }
                     if (!(myflags & cdf)) {
                         PrintOne(stream, vec[i], subname, subdesc, myprecision,
@@ -768,10 +776,8 @@ VectorDisplay(std::ostream &stream,
                         _pdf = vec[i] / _total;
                         _cdf += _pdf;
                     } else {
-                        _pdf = _cdf = 0.0;
+                        _pdf = _cdf = NAN;
                     }
-                    _pdf = vec[i] / _total;
-                    _cdf += _pdf;
                     PrintOne(stream, vec[i], name, mydesc, myprecision,
                              myflags, _pdf, _cdf);
                 }
diff --git a/cpu/simple_cpu/simple_cpu.cc b/cpu/simple_cpu/simple_cpu.cc
index 814902390..550b6c64f 100644
--- a/cpu/simple_cpu/simple_cpu.cc
+++ b/cpu/simple_cpu/simple_cpu.cc
@@ -160,7 +160,6 @@ SimpleCPU::SimpleCPU(const string &_name, Process *_process,
 
     numInst = 0;
     numLoad = 0;
-    last_idle = 0;
     lastIcacheStall = 0;
     lastDcacheStall = 0;
 
@@ -171,7 +170,6 @@ SimpleCPU::~SimpleCPU()
 {
 }
 
-
 void
 SimpleCPU::switchOut()
 {
@@ -229,11 +227,6 @@ SimpleCPU::regStats()
         .desc("Number of memory references")
         ;
 
-    idleCycles
-        .name(name() + ".idle_cycles")
-        .desc("Number of idle cycles")
-        ;
-
     idleFraction
         .name(name() + ".idle_fraction")
         .desc("Percentage of idle cycles")
@@ -251,8 +244,6 @@ SimpleCPU::regStats()
         .prereq(dcacheStallCycles)
         ;
 
-    idleFraction = idleCycles / simTicks;
-
     numInsts = Statistics::scalar(numInst);
     simInsts += numInsts;
 }
diff --git a/cpu/simple_cpu/simple_cpu.hh b/cpu/simple_cpu/simple_cpu.hh
index 6ad831218..d69d4e8de 100644
--- a/cpu/simple_cpu/simple_cpu.hh
+++ b/cpu/simple_cpu/simple_cpu.hh
@@ -207,7 +207,7 @@ class SimpleCPU : public BaseCPU
 
           case Idle:
             assert(old_status == Running);
-            last_idle = curTick;
+            idleFraction++;
             if (tickEvent.scheduled())
                 tickEvent.squash();
             break;
@@ -217,7 +217,7 @@ class SimpleCPU : public BaseCPU
                    old_status == DcacheMissStall ||
                    old_status == IcacheMissComplete);
             if (old_status == Idle && curTick != 0)
-                idleCycles += curTick - last_idle;
+                idleFraction--;
 
             if (tickEvent.squashed())
                 tickEvent.reschedule(curTick + 1);
@@ -244,9 +244,7 @@ class SimpleCPU : public BaseCPU
     Counter numLoad;
 
     // number of idle cycles
-    Statistics::Scalar<> idleCycles;
-    Statistics::Formula idleFraction;
-    Counter last_idle;
+    Statistics::Average<> idleFraction;
 
     // number of cycles stalled for I-cache misses
     Statistics::Scalar<> icacheStallCycles;
diff --git a/sim/main.cc b/sim/main.cc
index addedbc85..4fb075a2a 100644
--- a/sim/main.cc
+++ b/sim/main.cc
@@ -59,6 +59,7 @@ using namespace std;
 // See async.h.
 volatile bool async_event = false;
 volatile bool async_dump = false;
+volatile bool async_dumpreset = false;
 volatile bool async_exit = false;
 volatile bool async_io = false;
 volatile bool async_alarm = false;
@@ -71,6 +72,13 @@ dumpStatsHandler(int sigtype)
     async_dump = true;
 }
 
+void
+dumprstStatsHandler(int sigtype)
+{
+    async_event = true;
+    async_dumpreset = true;
+}
+
 /// Exit signal handler.
 void
 exitNowHandler(int sigtype)
@@ -219,8 +227,9 @@ main(int argc, char **argv)
     signal(SIGFPE, SIG_IGN);		// may occur on misspeculated paths
     signal(SIGPIPE, SIG_IGN);
     signal(SIGTRAP, SIG_IGN);
-    signal(SIGUSR1, dumpStatsHandler);	// dump intermediate stats
-    signal(SIGINT, exitNowHandler);	// dump final stats and exit
+    signal(SIGUSR1, dumpStatsHandler);		// dump intermediate stats
+    signal(SIGUSR2, dumprstStatsHandler);	// dump and reset stats
+    signal(SIGINT, exitNowHandler);		// dump final stats and exit
 
     sayHello(cerr);
 
@@ -405,6 +414,13 @@ main(int argc, char **argv)
                 SetupEvent(Dump, curTick);
             }
 
+            if (async_dumpreset) {
+                async_dumpreset = false;
+
+                using namespace Statistics;
+                SetupEvent(Dump | Reset, curTick);
+            }
+
             if (async_exit) {
                 async_exit = false;
                 new SimExitEvent("User requested STOP");
diff --git a/sim/sim_time.cc b/sim/sim_time.cc
index 70483d9a2..09c5a66de 100644
--- a/sim/sim_time.cc
+++ b/sim/sim_time.cc
@@ -65,6 +65,12 @@ namespace Time
         return start->tv;
     }
 
+    void
+    Start::reset()
+    {
+        ::gettimeofday(&start->tv, NULL);
+    }
+
     double
     Start::operator()() const
     {
@@ -115,10 +121,16 @@ namespace Time
         if (!elapsed)
             elapsed = new _timeval;
 
-        timersub(&now.get(), &start.get(), &elapsed->tv);
+        timersub(&_now.get(), &_start.get(), &elapsed->tv);
         return elapsed->tv;
     }
 
+    void
+    Elapsed::reset()
+    {
+        _start.reset();
+    }
+
     double
     Elapsed::operator()() const
     {
diff --git a/sim/sim_time.hh b/sim/sim_time.hh
index af69c3321..02ca5534f 100644
--- a/sim/sim_time.hh
+++ b/sim/sim_time.hh
@@ -45,6 +45,7 @@ namespace Time {
         ~Start();
 
         const timeval &get() const;
+        void reset();
         double operator()() const;
     };
 
@@ -65,12 +66,15 @@ namespace Time {
     {
       private:
         mutable _timeval *elapsed;
+        Start _start;
+        Now _now;
 
       public:
         Elapsed();
         ~Elapsed();
 
         const timeval &get() const;
+        void reset();
         double operator()() const;
     };