Files
reactics/smtcheckerrsc.py
2016-03-01 21:25:34 +01:00

421 lines
16 KiB
Python

"""
SMT-based Model Checking Module for RS with Concentrations and Context Automaton
"""
from z3 import *
from time import time
from sys import stdout
from itertools import chain
import resource
# def simplify(x):
# return x
class SmtCheckerRSC(object):
def __init__(self, rsca):
rsca.sanity_check()
if not rsca.is_with_concentrations():
raise RuntimeError("RS and CA with concentrations expected")
self.rs = rsca.rs
self.ca = rsca.ca
self.v = []
self.v_ctx = []
self.ca_state = []
self.next_level_to_encode = 0
self.solver = Solver()
self.verification_time = None
def prepare_all_variables(self):
"""Encodes all the variables"""
self.prepare_state_variables()
self.prepare_context_variables()
self.next_level_to_encode += 1
def prepare_context_variables(self):
"""Encodes all the context variables"""
level = self.next_level_to_encode
variables = []
for entity in self.rs.background_set:
variables.append(Int("C"+str(level)+"_"+entity))
self.v_ctx.append(variables)
def prepare_state_variables(self):
"""Encodes all the state variables"""
level = self.next_level_to_encode
variables = []
for entity in self.rs.background_set:
variables.append(Int("L"+str(level)+"_"+entity))
self.v.append(variables)
self.ca_state.append(Int("CA"+str(level)+"_state"))
def enc_init_state(self, level):
"""Encodes the initial state at the given level"""
rs_init_state_enc = True
for v in self.v[level]:
rs_init_state_enc = simplify(And(rs_init_state_enc, v == 0)) # the initial concentration levels are zeroed
ca_init_state_enc = self.ca_state[level] == self.ca.get_init_state_id()
init_state_enc = simplify(And(rs_init_state_enc, ca_init_state_enc))
return init_state_enc
def enc_produced_concentration(self, level, prod_entity):
"""Encodes the produced concentrations for the given level and entity"""
rcts_for_prod_entity = []
if prod_entity in self.rs.get_reactions_by_product():
rcts_for_prod_entity = self.rs.get_reactions_by_product()[prod_entity]
meta_reactions = []
if prod_entity in self.rs.meta_reactions:
meta_reactions = self.rs.meta_reactions[prod_entity]
if rcts_for_prod_entity == [] and meta_reactions == []:
return simplify(self.v[level+1][prod_entity] == 0) # this should never happen
enc_enabledness = False
# ----------- ordinary reactions --------------------------------------------
enc_rct_prod = False
for reactants,inhibitors,products in rcts_for_prod_entity:
enc_reactants = True
enc_inhibitors = True
# enc_products -- below
for reactant,concentration in reactants:
enc_reactants = simplify(And(enc_reactants,
Or(self.v[level][reactant] >= concentration, self.v_ctx[level][reactant] >= concentration)))
for inhibitor,concentration in inhibitors:
enc_inhibitors = simplify(And(enc_inhibitors,
And(self.v[level][inhibitor] < concentration, self.v_ctx[level][inhibitor] < concentration)))
enc_products = self.v[level+1][products[0][0]] == products[0][1]
enc_enabledness = simplify(Or(enc_enabledness, And(enc_reactants, enc_inhibitors)))
enc_rct_prod = simplify(Or(enc_rct_prod, And(enc_reactants, enc_inhibitors, enc_products)))
# -------- meta reactions ---------------------------------------------------
for r_type,command_entity,reactants,inhibitors in meta_reactions:
# command entity is e.g. 'inc' for incrementation operation
# (inc,W) gives us the value W by which the given entity's value should be incremented
enc_reactants = True
enc_inhibitors = True
for reactant,concentration in reactants:
enc_reactants = simplify(And(enc_reactants,
Or(self.v[level][reactant] >= concentration, self.v_ctx[level][reactant] >= concentration)))
# command entity needs to be present (with concentration level > 0) in order to perform the operation
enc_reactants = simplify(And(enc_reactants,
Or(self.v[level][command_entity] > 0, self.v_ctx[level][command_entity] > 0)))
for inhibitor,concentration in inhibitors:
enc_inhibitors = simplify(And(enc_inhibitors,
And(self.v[level][inhibitor] < concentration, self.v_ctx[level][inhibitor] < concentration)))
# if r_type == "inc":
# # depending on if the value of the command entity is greater in the context or in the current RS state
# # we choose to increment by the greater value from v or v_ctx (this is because we take the max value).
# enc_products = Or(
# And(self.v_ctx[level][command_entity] >= self.v[level][command_entity],
# self.v[level+1][prod_entity] == If(self.v[level][command_entity]>self.v_ctx[level][command_entity],self.v[level][command_entity],self.v_ctx[level][command_entity])+self.v_ctx[level][command_entity]),
# And(self.v[level][command_entity] > self.v_ctx[level][command_entity],
# self.v[level+1][prod_entity] == If(self.v[level][prod_entity]>self.v_ctx[level][command_entity],self.v[level][prod_entity],self.v_ctx[level][prod_entity])+self.v[level][command_entity]))
#
# elif r_type == "dec":
# # same happens here, but we decrement with the maximum value encoded at v or v_ctx.
# enc_products = Or(
# And(self.v_ctx[level][command_entity] >= self.v[level][command_entity],
# self.v[level+1][prod_entity] == If(self.v[level][prod_entity]>self.v_ctx[level][command_entity],self.v[level][prod_entity],self.v_ctx[level][prod_entity])-self.v_ctx[level][command_entity]),
# And(self.v[level][command_entity] > self.v_ctx[level][command_entity],
# self.v[level+1][prod_entity] == If(self.v[level][prod_entity]>self.v_ctx[level][command_entity],self.v[level][prod_entity],self.v_ctx[level][prod_entity])-self.v[level][command_entity]))
#
# if r_type == "inc":
# enc_products = self.v[level+1][prod_entity] == self.v[level][prod_entity]+1
#
# elif r_type == "dec":
# enc_products = self.v[level+1][prod_entity] == self.v[level][prod_entity]-1
if r_type == "inc":
enc_products = simplify(self.v[level+1][prod_entity] == \
If(self.v[level][prod_entity]>self.v_ctx[level][prod_entity],self.v[level][prod_entity],self.v_ctx[level][prod_entity]) + \
If(self.v[level][command_entity]>self.v_ctx[level][command_entity],self.v[level][command_entity],self.v_ctx[level][command_entity]))
elif r_type == "dec":
enc_products = simplify(self.v[level+1][prod_entity] == \
If(self.v[level][prod_entity]>self.v_ctx[level][prod_entity],self.v[level][prod_entity],self.v_ctx[level][prod_entity]) - \
If(self.v[level][command_entity]>self.v_ctx[level][command_entity],self.v[level][command_entity],self.v_ctx[level][command_entity]))
else:
raise RuntimeError("Unknown meta-reaction type: " + repr(r_type))
enc_enabledness = simplify(Or(enc_enabledness, And(enc_reactants, enc_inhibitors)))
enc_rct_prod = simplify(Or(enc_rct_prod, And(enc_reactants, enc_inhibitors, enc_products)))
# -----------------------------------------------------------------------------
enc_when_to_produce_zero_conc = simplify(And(Not(enc_enabledness), self.v[level+1][prod_entity] == 0))
enc_rct_prod = Or(enc_rct_prod, enc_when_to_produce_zero_conc)
return enc_rct_prod
# def enc_entity_production(self, level, prod_entity):
# """Encodes the production of a given entity from a given level at level+1"""
#
# enc_enab_cond = self.enc_enabledness(level, prod_entity)
#
# enc_ent_prod = Or(And(enc_enab_cond, self.v[level+1][prod_entity]),
# And(Not(enc_enab_cond), Not(self.v[level+1][prod_entity])))
#
# return simplify(enc_ent_prod)
def enc_transition_relation(self, level):
return simplify(And(self.enc_rs_trans(level), self.enc_automaton_trans(level)))
def enc_rs_trans(self, level):
"""Encodes the transition relation"""
unused_entities = set(range(len(self.rs.background_set)))
enc_trans = True
reactions = self.rs.get_reactions_by_product()
meta_reactions = self.rs.meta_reactions
for prod_entity in chain(reactions, meta_reactions):
unused_entities.discard(prod_entity)
enc_trans = simplify(And(enc_trans, self.enc_produced_concentration(level, prod_entity)))
for prod_entity in unused_entities:
enc_trans = simplify(And(enc_trans, self.v[level+1][prod_entity] == 0))
return enc_trans
def enc_automaton_trans(self, level):
"""Encodes the transition relation for the context automaton"""
enc_trans = False
for src,ctx,dst in self.ca.transitions:
src_enc = self.ca_state[level] == src
dst_enc = self.ca_state[level+1] == dst
all_ent = set(range(len(self.rs.background_set)))
incl_ctx = set([e for e,c in ctx])
excl_ctx = all_ent - incl_ctx
ctx_enc = True
for e,c in ctx:
ctx_enc = simplify(And(ctx_enc, self.v_ctx[level][e] == c))
for e in excl_ctx:
ctx_enc = simplify(And(ctx_enc, self.v_ctx[level][e] == 0))
cur_trans = simplify(And(src_enc, ctx_enc, dst_enc))
enc_trans = simplify(Or(enc_trans, cur_trans))
return enc_trans
def enc_exact_state(self, level, state):
"""Encodes the state at the given level with the exact concentration values"""
raise RuntimeError("Should not be used with RSC")
# enc = True
# used_entities_ids = self.rs.get_state_ids(state)
#
# for ent,conc in state:
# e_id = self.rs.get_entity_id(ent)
# enc = And(enc, self.v[level][e_id] == conc)
#
# not_in_state = set(range(len(self.rs.background_set)))
# not_in_state = not_in_state.difference(set(used_entities_ids))
#
# for entity in not_in_state:
# enc = And(enc, self.v[level][entity] == 0)
#
# return simplify(enc)
def enc_min_state(self, level, state):
"""Encodes the state at the given level with the minimal required concentration levels"""
enc = True
for ent,conc in state:
e_id = self.rs.get_entity_id(ent)
enc = And(enc, self.v[level][e_id] >= conc)
# state_ids = self.rs.get_state_ids(state)
#
# for entity in state_ids:
# enc = And(enc, self.v[level][entity])
return simplify(enc)
def decode_witness(self, max_level, print_model=False):
m = self.solver.model()
if print_model:
print(m)
for level in range(max_level+1):
print("\n[Level=" + repr(level) + "]")
print(" State: {", end=""),
for var_id in range(len(self.v[level])):
var_rep = repr(m[self.v[level][var_id]])
if not var_rep.isdigit():
raise RuntimeError("unexpected: representation is not a positive integer")
if int(var_rep) > 0:
print(" " + self.rs.get_entity_name(var_id) + "=" + var_rep, end="")
# print(" " + repr(m[self.v[level][var_id]]), end="")
print(" }")
if level != max_level:
print(" Context set: ", end="")
print("{", end="")
for var_id in range(len(self.v[level])):
var_rep = repr(m[self.v_ctx[level][var_id]])
if not var_rep.isdigit():
raise RuntimeError("unexpected: representation is not a positive integer")
if int(var_rep) > 0:
print(" " + self.rs.get_entity_name(var_id) + "=" + var_rep, end="")
print(" }")
def check_reachability(self, state, print_witness=True,
print_time=True, print_mem=True, max_level=100):
"""Main testing function"""
if print_time:
# start = time()
start = resource.getrusage(resource.RUSAGE_SELF).ru_utime
self.prepare_all_variables()
self.solver.add(self.enc_init_state(0))
current_level = 0
self.prepare_all_variables()
while True:
self.prepare_all_variables()
print("-----[ Working at level=" + str(current_level) + " ]-----")
stdout.flush()
# reachability test:
print("[i] Adding the reachability test...")
self.solver.push()
self.solver.add(self.enc_min_state(current_level,state))
result = self.solver.check()
if result == sat:
print("\n[+] SAT at level=" + str(current_level))
if print_witness:
self.decode_witness(current_level)
break
else:
self.solver.pop()
print("[i] Unrolling the transition relation")
self.solver.add(self.enc_transition_relation(current_level))
print("-----[ level=" + str(current_level) + " done ]")
current_level += 1
if current_level > max_level:
print("Stopping at level=" + str(max_level))
break
if print_time:
# stop = time()
stop = resource.getrusage(resource.RUSAGE_SELF).ru_utime
self.verification_time = stop-start
print()
print("[i] Time: " + repr(self.verification_time))
if print_mem:
print("[i] Memory: " + repr(resource.getrusage(resource.RUSAGE_SELF).ru_maxrss/(1024*1024)) + " MB")
def get_verification_time(self):
return self.verification_time
def show_encoding(self, state, print_witness=True,
print_time=False, print_mem=False, max_level=100):
"""Encoding debug function"""
self.prepare_all_variables()
init_s = self.enc_init_state(0)
print(init_s)
self.solver.add(init_s)
current_level = 0
self.prepare_all_variables()
while True:
self.prepare_all_variables()
print("-----[ Working at level=" + str(current_level) + " ]-----")
stdout.flush()
# reachability test:
print("[i] Adding the reachability test...")
self.solver.push()
s = self.enc_min_state(current_level,state)
print("Test: ", s)
self.solver.add(s)
result = self.solver.check()
if result == sat:
print("\n[+] SAT at level=" + str(current_level))
if print_witness:
self.decode_witness(current_level)
break
else:
self.solver.pop()
print("[i] Unrolling the transition relation")
t = self.enc_transition_relation(current_level)
print(t)
self.solver.add(t)
print("-----[ level=" + str(current_level) + " done ]")
current_level += 1
x=input("Next level? ")
x=x.lower()
if not (x == "y" or x == "yes"):
break
if current_level > max_level:
print("Stopping at level=" + str(max_level))
break