def reset_and_eval():
alice = Account("alice", 5)
bob = Account("bob", 5)
ev = timewinder.Evaluator(
objects=[alice, bob],
threads=[
check_and_withdraw(alice, bob, Set(range(1, 6))),
check_and_withdraw(alice, bob, Set(range(1, 6))),
],
specs=[no_overdrafts],
)
ev.evaluate(steps=10)
return ev.stats
def test_overdraft_initial_conditions():
alice = Account("alice", 5)
bob = Account("bob", 5)
@timewinder.process
def withdraw(sender, reciever, amount):
sender.acc = sender.acc - amount
yield "deposit"
reciever.acc = reciever.acc + amount
no_overdrafts = timewinder.ForAll(Account, lambda a: a.acc >= 0)
ev = timewinder.Evaluator(
objects=[alice, bob],
threads=[withdraw(alice, bob, Set(range(1, 7)))],
specs=[no_overdrafts],
)
got_error = False
try:
ev.evaluate()
except ConstraintError as e:
got_error = True
print(e.name)
print(e.thunk)
assert got_error
assert ev.stats.states == 12
def alg():
return timewinder.FuncProcess(
check_funds(alice),
withdraw(alice),
deposit(bob),
state={"amt": Set(range(1, 6))},
)
def test_liveness_reinterp():
@timewinder.process
def check_and_withdraw(sender, reciever, amt):
if amt <= sender.acc:
sender.acc = sender.acc - amt
yield "deposit"
reciever.acc = reciever.acc + amt
no_overdrafts = timewinder.ForAll(Account, lambda a: a.acc >= 0)
@timewinder.predicate
def consistent_total(a, b):
total = a.acc + b.acc
return total == 10
alice = Account("alice", 5)
bob = Account("bob", 5)
eventually_consistent = timewinder.Eventually(
timewinder.Always(consistent_total(alice, bob)))
ev = timewinder.Evaluator(
objects=[alice, bob],
threads=[
check_and_withdraw(alice, bob, Set(range(1, 6))),
check_and_withdraw(alice, bob, Set(range(1, 6))),
],
specs=[
no_overdrafts,
eventually_consistent,
],
)
got_error = False
try:
ev.evaluate(steps=10)
except StutterConstraintError as s:
got_error = True
print("\n" + s.name + "\n")
ev.replay_thunk(s.thunk)
assert got_error
def producer(queue, running, id):
while True:
if not running.status[id]:
yield "paused"
continue
if queue.is_full():
running.status[id] = False
continue
queue.queue.append(4) # 4 represents arbitrary data
sleeping = running.sleeping()
if len(sleeping) != 0:
wake_id = Set(sleeping)
running.notify(wake_id)
def consumer(queue, running, id):
while True:
if not running.status[id]:
yield "paused"
continue
if queue.is_empty():
running.status[id] = False
continue
queue.queue.pop()
sleeping = running.sleeping()
if len(sleeping) != 0:
wake_id = Set(sleeping)
running.notify(wake_id)
def test_overdraft_initial_conditions():
@timewinder.object
class Account:
def __init__(self, name):
self.name = name
self.acc = 5
alice = Account("alice")
bob = Account("bob")
@timewinder.step
def withdraw(state, sender):
sender.acc = sender.acc - state["amt"]
@timewinder.step
def deposit(state, reciever):
reciever.acc = reciever.acc + state["amt"]
alg = timewinder.FuncProcess(
withdraw(alice),
deposit(bob),
state={
"amt": Set(range(1, 7)),
},
)
no_overdrafts = timewinder.ForAll(Account, lambda a: a.acc >= 0)
ev = timewinder.Evaluator(
objects=[alice, bob],
threads=[alg],
specs=[no_overdrafts],
)
got_error = False
try:
ev.evaluate()
except ConstraintError as e:
got_error = True
print(e.name)
print(e.thunk)
assert got_error
assert ev.stats.states == 12