def test_uncancellable(self):
"""
If a request is being waited on by a regular thread, it can't be cancelled.
"""
def workload():
time.sleep(0.1)
return 1
def big_workload():
result = 0
requests = []
for i in range(10):
requests.append( Request(workload) )
for r in requests:
result += r.wait()
return result
req = Request(big_workload)
def attempt_cancel():
time.sleep(1)
req.cancel()
# Start another thread that will try to cancel the request.
# It won't have any effect because we're already waiting for it in a non-request thread.
t = threading.Thread(target=attempt_cancel)
t.start()
result = req.wait()
assert result == 10
t.join()
def test_basic(self):
"""
Fire a couple requests and check the answer they give.
"""
def someWork():
time.sleep(0.001)
return "Hello,"
callback_result = ['']
def callback(result):
callback_result[0] = result
def test(s):
req = Request(someWork)
req.notify_finished(callback)
s2 = req.wait()
time.sleep(0.001)
return s2 + s
req = Request( partial(test, s = " World!") )
req.notify_finished(callback)
# Wait for the result
assert req.wait() == "Hello, World!" # Wait for it
assert req.wait() == "Hello, World!" # It's already finished, should be same answer
assert callback_result[0] == "Hello, World!" # From the callback
requests = []
for i in range(10):
req = Request( partial(test, s = "hallo %d" %i) )
requests.append(req)
for r in requests:
r.wait()
def test_callbacks_before_wait_returns(self):
"""
If the user adds callbacks to the request via notify_finished() BEFORE the request is submitted,
then wait() should block for the completion of all those callbacks before returning.
Any callbacks added AFTER the request has already been submitted are NOT guaranteed
to be executed before wait() returns, but they will still be executed.
"""
def someQuickWork():
return 42
callback_results = []
def slowCallback(n, result):
time.sleep(0.1)
callback_results.append(n)
req = Request( someQuickWork )
req.notify_finished( partial(slowCallback, 1) )
req.notify_finished( partial(slowCallback, 2) )
req.notify_finished( partial(slowCallback, 3) )
result = req.wait()
assert result == 42
assert callback_results == [1,2,3], "wait() returned before callbacks were complete! Got: {}".format( callback_results )
req.notify_finished( partial(slowCallback, 4) )
req.wait()
assert callback_results == [1,2,3,4], "Callback on already-finished request wasn't executed."
def test(s, destination=None,):
req = Request(someWork)
req.onFinish(callback)
s2 = req.wait()[0]
time.sleep(0.001)
if destination is None:
destination = [""]
destination[0] = s2 + s
return destination
def test_lotsOfSmallRequests(self):
"""
Fire off some reasonably large random number of nested requests.
Mostly, this test ensures that the requests all complete without a hang.
"""
handlerCounter = [0]
handlerLock = threading.Lock()
def completionHandler( result, req ):
logger.debug( "Handing completion {}".format(result) )
handlerLock.acquire()
handlerCounter[0] += 1
handlerLock.release()
req.calledHandler = True
requestCounter = [0]
requestLock = threading.Lock()
allRequests = []
# This closure randomly chooses to either (a) return immediately or (b) fire off more work
def someWork(depth, force=False, i=-1):
#print 'depth=', depth, 'i=', i
if depth > 0 and (force or random.random() > 0.5):
requests = []
for i in range(10):
req = Request( partial(someWork, depth=depth-1, i=i) )
req.notify_finished( partial(completionHandler, req=req) )
requests.append(req)
allRequests.append(req)
requestLock.acquire()
requestCounter[0] += 1
requestLock.release()
for r in requests:
r.wait()
return requestCounter[0]
req = Request( partial(someWork, depth=4, force=True) )
logger.debug("Waiting for requests...")
req.wait()
logger.debug("root request finished")
# Handler should have been called once for each request we fired
assert handlerCounter[0] == requestCounter[0]
logger.debug("finished testLotsOfSmallRequests")
for r in allRequests:
assert r.finished
logger.debug("waited for all subrequests")
def testRequestLock(self):
"""
Test the special Request-aware lock.
Launch 99 requests and threads that all must fight over access to the same list.
The list will eventually be 0,1,2...99, and each request will append a single number to the list.
Each request must wait its turn before it can append it's number and finish.
"""
req_lock = RequestLock()
l = [0]
def append_n(n):
#print "Starting append_{}\n".format(n)
while True:
with req_lock:
if l[-1] == n-1:
#print "***** Appending {}".format(n)
l.append(n)
return
# Create 50 requests
reqs = []
for i in range(1,100,2):
req = Request( partial(append_n, i) )
reqs.append(req)
# Create 49 threads
thrds = []
for i in range(2,100,2):
thrd = threading.Thread( target=partial(append_n, i) )
thrds.append(thrd)
# Submit in reverse order to ensure that no request finishes until they have all been started.
# This proves that the requests really are being suspended.
for req in reversed(reqs):
req.submit()
# Start all the threads
for thrd in reversed(thrds):
thrd.start()
# All requests must finish
for req in reqs:
req.wait()
# All threads should finish
for thrd in thrds:
thrd.join()
assert l == list(range(100)), "Requests and/or threads finished in the wrong order!"
def test_early_cancel(self):
"""
If you try to wait for a request after it's already been cancelled, you get a InvalidRequestException.
"""
def f():
pass
req = Request(f)
req.cancel()
try:
req.wait()
except Request.InvalidRequestException:
pass
else:
assert False, "Expected a Request.InvalidRequestException because we're waiting for a request that's already been cancelled."
def testExceptionPropagation(self):
"""
When an exception is generated in a request, the exception should be propagated to all waiting threads.
Also, the failure signal should fire.
"""
class SpecialException(Exception):
pass
def always_fails():
time.sleep(0.2)
raise SpecialException()
req1 = Request(always_fails)
def wait_for_req1():
req1.wait()
req2 = Request(wait_for_req1)
req3 = Request(wait_for_req1)
signaled_exceptions = []
def failure_handler(ex):
signaled_exceptions.append(ex)
req2.notify_failed( failure_handler )
req3.notify_failed( failure_handler )
caught_exceptions = []
def wait_for_request(req):
try:
req.wait()
except SpecialException as ex:
caught_exceptions.append(ex)
except:
raise # Got some other exception than the one we expected
else:
assert "Expected to get an exception. Didn't get one."
th2 = threading.Thread( target=partial( wait_for_request, req2 ) )
th3 = threading.Thread( target=partial( wait_for_request, req3 ) )
th2.start()
th3.start()
th2.join()
th3.join()
assert len(caught_exceptions) == 2, "Expected both requests to catch exceptions."
assert len(signaled_exceptions) == 2, "Expected both requests to signal failure."
assert isinstance( caught_exceptions[0], SpecialException ), "Caught exception was of the wrong type."
assert caught_exceptions[0] == caught_exceptions[1] == signaled_exceptions[0] == signaled_exceptions[1]
# Attempting to wait for a request that has already failed will raise the exception that causes the failure
wait_for_request(req2)
# Subscribing to notify_failed on a request that's already failed should call the failure handler immediately.
req2.notify_failed( failure_handler )
assert len(signaled_exceptions) == 3
def test_callWaitDuringCallback(self):
"""
When using request.notify_finished(...) to handle request completions,
the handler should be allowed to call request.wait() on the request that it's handling.
"""
def handler(req, result):
req.wait()
def workFn():
pass
req = Request(workFn)
req.notify_finished( partial(handler, req) )
#req.submit()
req.wait()
def test_request_timeout(self):
"""
Test the timeout feature when calling wait() from a foreign thread.
See wait() for details.
"""
def slowWorkload():
time.sleep( 10.0 )
req = Request( slowWorkload )
try:
req.wait(0.5)
except Request.TimeoutException:
pass
else:
assert False, "Expected to get Request.TimeoutException"
def testThreadPoolReset(self):
Request.reset_thread_pool(num_workers=1)
lock = threading.Lock()
def check_for_contention():
assert lock.acquire(False), "Should not be contention for this lock!"
time.sleep(0.1)
lock.release()
reqs = map( lambda x: Request( check_for_contention ), range(10) )
for req in reqs:
req.submit()
for req in reqs:
req.wait()
# Set it back to what it was
Request.reset_thread_pool()
def test_failed_request(self):
"""
A request is "failed" if it throws an exception while executing.
The exception should be forwarded to ALL waiting requests.
"""
def impossible_workload():
raise RuntimeError("Can't service your request")
req = Request(impossible_workload)
try:
req.wait()
except RuntimeError:
pass
else:
assert False, "Expected an exception from that request, but didn't get it."
def test_block_during_calback(self):
"""
It is valid for request finish handlers to fire off and wait for requests.
This tests that feature.
"""
def workload():
time.sleep(0.1)
return 1
total_result = [0]
def handler(result):
req = Request(workload)
total_result[0] = result + req.wait() # Waiting on some other request from WITHIN a request callback
req = Request( workload )
req.notify_finished( handler )
assert req.wait() == 1
assert total_result[0] == 2
def someWork(depth, force=False, i=-1):
#print 'depth=', depth, 'i=', i
if depth > 0 and (force or random.random() > 0.5):
requests = []
for i in range(10):
req = Request( partial(someWork, depth=depth-1, i=i) )
req.notify_finished( partial(completionHandler, req=req) )
requests.append(req)
allRequests.append(req)
requestLock.acquire()
requestCounter[0] += 1
requestLock.release()
for r in requests:
r.wait()
return requestCounter[0]
def testWorkerThreadLoopProtection(self):
"""
The worker threads should not die due to an exception raised within a request.
"""
for worker in Request.global_thread_pool.workers:
assert worker.is_alive(), "Something is wrong with this test. All workers should be alive."
def always_fails():
raise Exception()
req = Request(always_fails)
req.submit()
try:
req.wait()
except:
pass
else:
assert False, "Expected to request to raise an Exception!"
for worker in Request.global_thread_pool.workers:
assert worker.is_alive(), "An exception was propagated to a worker run loop!"
def getBigArray(directExecute, recursionDepth):
"""
Simulate the memory footprint of a series of computation steps.
"""
logger.debug( "Usage delta before depth {}: {} MB".format(recursionDepth, getMemoryIncreaseMb() ) )
if recursionDepth == 0:
# A 500GB result
result = numpy.zeros(shape=resultShape, dtype=numpy.uint8)
else:
req = Request( partial(getBigArray, directExecute=directExecute, recursionDepth=recursionDepth-1) )
if not directExecute:
# Force this request to be submitted to the thread pool,
# not executed synchronously in this thread.
req.submit()
result = req.wait() + 1
# Note that we expect there to be 2X memory usage here:
# 1x for our result and 1x for the child, which hasn't been cleaned up yet.
memory_increase_mb = getMemoryIncreaseMb()
logger.debug( "Usage delta after depth {}: {} MB".format(recursionDepth, memory_increase_mb ) )
assert memory_increase_mb < 2.5*resultSize, "Memory from finished requests didn't get freed!"
return result
def test_cancel_basic(self):
"""
Start a workload and cancel it. Verify that it was actually cancelled before all the work was finished.
"""
counter_lock = threading.RLock()
def workload():
time.sleep(0.1)
return 1
got_cancel = [False]
workcounter = [0]
def big_workload():
try:
requests = []
for i in range(100):
requests.append( Request(workload) )
for r in requests:
workcounter[0] += r.wait()
assert False, "Shouldn't get to this line. This test is designed so that big_workload should be cancelled before it finishes all its work"
for r in requests:
assert not r.cancelled
except Request.CancellationException:
got_cancel[0] = True
completed = [False]
def handle_complete( result ):
completed[0] = True
req = Request( big_workload )
req.notify_finished( handle_complete )
req.submit()
time.sleep(.5)
req.cancel()
assert req.cancelled
time.sleep(2)
assert not completed[0]
assert got_cancel[0]
# Make sure this test is functioning properly:
# The cancellation should have occurred in the middle (not before the request even got started)
# If not, then adjust the timing of the cancellation, above.
assert workcounter[0] != 0
assert workcounter[0] != 100
def test_old_api_support(self):
"""
For now, the request_rewrite supports the old interface, too.
"""
def someWork(destination=None):
if destination is None:
destination = [""]
time.sleep(0.001)
destination[0] = "Hello,"
return destination
callback_result = [ [] ]
def callback(result):
callback_result[0] = result[0]
def test(s, destination=None,):
req = Request(someWork)
req.onFinish(callback)
s2 = req.wait()[0]
time.sleep(0.001)
if destination is None:
destination = [""]
destination[0] = s2 + s
return destination
req = Request( partial(test, s = " World!") )
preAllocatedResult = [""]
req.writeInto(preAllocatedResult)
req.notify(callback)
# Wait for the result
assert req.wait()[0] == "Hello, World!" # Wait for it
assert callback_result[0] == "Hello, World!" # From the callback
assert preAllocatedResult[0] == req.wait()[0], "This might fail if the request was started BEFORE writeInto() was called"
requests = []
for i in range(10):
req = Request( partial(test, s = "hallo %d" %i) )
requests.append(req)
for r in requests:
r.wait()
def handler(result):
req = Request(workload)
total_result[0] = result + req.wait() # Waiting on some other request from WITHIN a request callback
def test_impl(directExecute):
rootReq = Request( partial( getBigArray, directExecute, recursionDepth=5 ) )
result = rootReq.wait()
assert (result == 5).all()
def test_dont_cancel_shared_request(self):
"""
Test that a request isn't cancelled if it has requests pending for it.
"""
cancelled_requests = []
def f1():
time.sleep(1)
return "RESULT"
r1 = Request(f1)
r1.notify_cancelled( partial(cancelled_requests.append, 1) )
def f2():
try:
return r1.wait()
except:
cancelled_requests.append(2)
r2 = Request(f2)
def f3():
try:
return r1.wait()
except:
cancelled_requests.append(3)
r3 = Request(f3)
def otherThread():
r2.wait()
t = threading.Thread(target=otherThread)
t.start()
r3.submit()
time.sleep(0.5)
# By now both r2 and r3 are waiting for the result of r1
# Cancelling r3 should not cancel r1.
r3.cancel()
t.join() # Wait for r2 to finish
time.sleep(0.5)
assert r1.started
assert r1.finished
assert not r1.cancelled # Not cancelled, even though we cancelled a request that was waiting for it.
assert 1 not in cancelled_requests
assert r2.started
assert r2.finished
assert not r2.cancelled # Not cancelled.
assert 1 not in cancelled_requests
assert r2.wait() == "RESULT"
assert r3.started
assert r3.finished
assert r3.cancelled # Successfully cancelled.
assert 3 in cancelled_requests
def test(s):
req = Request(someWork)
req.notify_finished(callback)
s2 = req.wait()
time.sleep(0.001)
return s2 + s
def test_failed_request2(self):
"""
A request is "failed" if it throws an exception while executing.
The exception should be forwarded to ALL waiting requests, which should re-raise it.
"""
class CustomRuntimeError(RuntimeError):
pass
def impossible_workload():
time.sleep(0.2)
raise CustomRuntimeError("Can't service your request")
impossible_req = Request(impossible_workload)
def wait_for_impossible():
# This request will fail...
impossible_req.wait()
# Since there are some exception guards in the code we're testing,
# spit something out to stderr just to be sure this error
# isn't getting swallowed accidentally.
sys.stderr.write("ERROR: Shouldn't get here.")
assert False, "Shouldn't get here."
req1 = Request(wait_for_impossible)
req2 = Request(wait_for_impossible)
failed_ids = []
lock = threading.Lock()
def handle_failed_req(req_id, failure_exc):
assert isinstance(failure_exc, CustomRuntimeError)
with lock:
failed_ids.append(req_id)
req1.notify_failed( partial(handle_failed_req, 1) )
req2.notify_failed( partial(handle_failed_req, 2) )
req1.submit()
req2.submit()
try:
req1.wait()
except RuntimeError:
pass
else:
assert False, "Expected an exception from that request, but didn't get it."
try:
req2.wait()
except RuntimeError:
pass
else:
assert False, "Expected an exception from that request, but didn't get it."
assert 1 in failed_ids
assert 2 in failed_ids
