Add 'passive' simulation functions that are not taken into account while determining when to stop the simulator

migen/bus/lasmibus.py

@@ -260,6 +260,7 @@ class _ReqFIFO(Module):
 		else:
 			selfp.bank.req_ack = 0
 		selfp.bank.lock = bool(self.contents)
+	do_simulation.passive = True
 
 class Target(Module):
 	def __init__(self, model, *ifargs, **ifkwargs):
@@ -305,3 +306,4 @@ class Target(Module):
 		if done_wr_transaction is not None:
 			self.model.write(done_wr_transaction[0], done_wr_transaction[1],
 				selfp.bus.dat_w, selfp.bus.dat_we)
+	do_simulation.passive = True

migen/bus/wishbone.py

@@ -212,6 +212,7 @@ class Tap(Module):
 				transaction = TRead(selfp.bus.adr,
 					selfp.bus.dat_r)
 			self.handler(transaction)
+	do_simulation.passive = True
 
 class Initiator(Module):
 	def __init__(self, generator, bus=None):
@@ -277,6 +278,7 @@ class Target(Module):
 				bus.ack = 1
 		else:
 			bus.ack = 0
+	do_simulation.passive = True
 
 class SRAM(Module):
 	def __init__(self, mem_or_size, read_only=None, init=None, bus=None):

migen/fhdl/module.py

@@ -5,7 +5,7 @@ from migen.util.misc import flat_iteration
 from migen.fhdl.structure import *
 from migen.fhdl.structure import _Fragment
 from migen.fhdl.tools import rename_clock_domain
-from migen.sim.upper import GenSim, ProxySim
+from migen.sim.upper import gen_sim, proxy_sim
 
 class FinalizeError(Exception):
 	pass
@@ -115,11 +115,9 @@ class Module:
 				except AttributeError:
 					pass
 				else:
-					gs = GenSim(simg)
-					simf = gs.do_simulation
+					simf = gen_sim(simg)
 			if simf is not None:
-				ps = ProxySim(self, simf)
-				simf = ps.do_simulation
+				simf = proxy_sim(self, simf)
 			sim = [] if simf is None else [simf]
 			self._fragment = _Fragment(sim=sim)
 			return self._fragment

migen/sim/generic.py

@@ -72,16 +72,6 @@ end
 		r += "\nendmodule"
 		return r
 
-def _call_sim(fragment, simulator):
-	del_list = []
-	for s in fragment.sim:
-		try:
-			s(simulator)
-		except StopSimulation:
-			del_list.append(s)
-	for s in del_list:
-		fragment.sim.remove(s)
-
 class Simulator:
 	def __init__(self, fragment, top_level=None, sim_runner=None, sockaddr="simsocket", **vopts):
 		if not isinstance(fragment, _Fragment):
@@ -90,14 +80,14 @@ class Simulator:
 			top_level = TopLevel()
 		if sim_runner is None:
 			sim_runner = icarus.Runner()
-		self.fragment = fragment + _Fragment(clock_domains=top_level.clock_domains)
 		self.top_level = top_level
 		self.ipc = Initiator(sockaddr)
 		self.sim_runner = sim_runner
 		
 		c_top = self.top_level.get(sockaddr)
 		
-		c_fragment, self.namespace = verilog.convert(self.fragment,
+		fragment = fragment + _Fragment(clock_domains=top_level.clock_domains)
+		c_fragment, self.namespace = verilog.convert(fragment,
 			ios=self.top_level.ios,
 			name=self.top_level.dut_type,
 			return_ns=True,
@@ -111,15 +101,30 @@ class Simulator:
 		reply = self.ipc.recv()
 		assert(isinstance(reply, MessageTick))
 
+		self.sim_functions = fragment.sim
+		self.active_sim_functions = set(f for f in fragment.sim if not hasattr(f, "passive") or not f.passive)
+	
 	def run(self, ncycles=None):
 		counter = 0
-		while self.fragment.sim and (ncycles is None or counter < ncycles):
+		while self.active_sim_functions and (ncycles is None or counter < ncycles):
 			self.cycle_counter += 1
 			counter += 1
 			self.ipc.send(MessageGo())
 			reply = self.ipc.recv()
 			assert(isinstance(reply, MessageTick))
-			_call_sim(self.fragment, self)
+
+			del_list = []
+			for s in self.sim_functions:
+				try:
+					s(self)
+				except StopSimulation:
+					del_list.append(s)
+			for s in del_list:
+				self.sim_functions.remove(s)
+				try:
+					self.active_sim_functions.remove(s)
+				except KeyError:
+					pass
 
 	def rd(self, item, index=0):
 		name = self.top_level.top_name + "." \

migen/sim/upper.py

@@ -52,48 +52,58 @@ class Proxy:
 		assert(isinstance(item, Signal))
 		self.simulator.wr(item, value)
 
-class GenSim:
-	def __init__(self, simg):
-		self.simg = simg
-		self.gens = dict()
-		self.resume_cycle = 0
+def gen_sim(simg):
+	gens = dict()
+	resume_cycle = 0
+
+	def do_simulation(s):
+		nonlocal resume_cycle, gens
 
-	def do_simulation(self, s):
 		if isinstance(s, Proxy):
 			simulator = s.simulator
 		else:
 			simulator = s
 
-		if simulator.cycle_counter >= self.resume_cycle:
+		if simulator.cycle_counter >= resume_cycle:
 			try:
-				gen = self.gens[simulator]
+				gen = gens[simulator]
 			except KeyError:
-				gen = self.simg(s)
-				self.gens[simulator] = gen
+				gen = simg(s)
+				gens[simulator] = gen
 			try:
 				n = next(gen)
 			except StopIteration:
-				del self.gens[simulator]
+				del gens[simulator]
 				raise StopSimulation
 			else:
 				if n is None:
 					n = 1
-				self.resume_cycle = simulator.cycle_counter + n
+				resume_cycle = simulator.cycle_counter + n
 
-class ProxySim:
-	def __init__(self, target, simf):
-		self.target = target
-		self.simf = simf
-		self.proxies = dict()
+	if hasattr(simg, "passive"):
+		do_simulation.passive = simg.passive
+
+	return do_simulation
+
+
+def proxy_sim(target, simf):
+	proxies = dict()
+
+	def do_simulation(simulator):
+		nonlocal proxies
 
-	def do_simulation(self, simulator):
 		try:
-			proxy = self.proxies[simulator]
+			proxy = proxies[simulator]
 		except KeyError:
-			proxy = Proxy(simulator, self.target)
-			self.proxies[simulator] = proxy
+			proxy = Proxy(simulator, target)
+			proxies[simulator] = proxy
 		try:
-			self.simf(proxy)
+			simf(proxy)
 		except StopSimulation:
-			del self.proxies[simulator]
+			del proxies[simulator]
 			raise
+
+	if hasattr(simf, "passive"):
+		do_simulation.passive = simf.passive
+
+	return do_simulation