Merge pull request #149 from srivatsansoft/master

A single simulation instance fix for issue #104

myhdl/_Simulation.py

@@ -45,6 +45,7 @@ class _error:
 _error.ArgType = "Inappriopriate argument type"
 _error.MultipleCosim = "Only a single cosimulator argument allowed"
 _error.DuplicatedArg = "Duplicated argument"
+_error.MultipleSim = "Only a single Simulation instance is allowed"
 
 class Simulation(object):
 
@@ -54,6 +55,7 @@ class Simulation(object):
     run -- run a simulation for some duration
 
     """
+    _no_of_instances = 0
 
     def __init__(self, *args):
         """ Construct a simulation object.
@@ -65,13 +67,16 @@ def __init__(self, *args):
         _simulator._time = 0
         arglist = _flatten(*args)
         self._waiters, self._cosim = _makeWaiters(arglist)
+        if Simulation._no_of_instances > 0:
+            raise SimulationError(_error.MultipleSim)
+        Simulation._no_of_instances += 1
         if not self._cosim and _simulator._cosim:
             warn("Cosimulation not registered as Simulation argument")
         self._finished = False
         del _futureEvents[:]
         del _siglist[:]
-        
-        
+
+
     def _finalize(self):
         cosim = self._cosim
         if cosim:
@@ -85,9 +90,12 @@ def _finalize(self):
         # clean up for potential new run with same signals
         for s in _signals:
             s._clear()
+        Simulation._no_of_instances = 0
         self._finished = True
-
-
+
+    def quit(self):
+        self._finalize()
+
     def runc(self, duration=0, quiet=0):
         simrunc.run(sim=self, duration=duration, quiet=quiet)
 
@@ -201,7 +209,7 @@ def run(self, duration=None, quiet=0):
                     self._finalize()
                 # now reraise the exepction
                 raise
-                
+
 
 def _makeWaiters(arglist):
     waiters = []
@@ -231,4 +239,4 @@ def _makeWaiters(arglist):
         if hasattr(sig, '_waiter'):
             waiters.append(sig._waiter)
     return waiters, cosim
-        
+

myhdl/test/bugs/test_issue_104.py

@@ -0,0 +1,43 @@
+from __future__ import print_function
+import pytest
+from myhdl import Simulation, delay, SimulationError, instance, now
+from myhdl._Simulation import _error
+from helpers import raises_kind
+
+def test():
+  @instance
+  def tbstim():
+    yield delay(10)
+    print("{0:<8d} ".format(now()))
+    yield delay(1000)
+    print("{0:<8d} ".format(now()))
+    for _ in range(10):
+      yield delay(1000)
+
+  return tbstim
+
+
+def issue_104_quit_method():
+    sim = Simulation(test())
+    sim.run(1000)
+    sim.run(500)
+    sim.quit()
+    return sim._finished
+
+def issue_104_multiple_instance():
+    sim1 = Simulation(test())
+    sim1.run(1000)
+    # sim1 is "puased"
+
+    # try and create a second, third, forth simulation instance
+    for ii in range(4):
+        with raises_kind(SimulationError, _error.MultipleSim):
+              another_sim = Simulation(test())
+    # generating more sims should have failed
+    sim1.run(1000)
+    sim1.quit()
+
+def test_issue_104():
+
+    assert issue_104_quit_method() == True
+    issue_104_multiple_instance()

myhdl/test/core/test_traceSignals.py

@@ -155,12 +155,16 @@ def testHierarchicalTrace2(self, vcd_dir):
         assert not path.exists(psub)
 
     def testTristateTrace(self, vcd_dir):
-        Simulation(topTristate()).run(100, quiet=QUIET)
+        sim = Simulation(topTristate())
+        sim.run(100, quiet=QUIET)
+        sim.quit()
 
     def testBackupOutputFile(self, vcd_dir):
         p = "%s.vcd" % fun.__name__
         dut = traceSignals(fun)
-        Simulation(dut).run(1000, quiet=QUIET)
+        sim = Simulation(dut)
+        sim.run(1000, quiet=QUIET)
+        sim.quit()
         _simulator._tf.close()
         _simulator._tracing = 0
         size = path.getsize(p)