nim-chronos/tests/testtime.nim
Jacek Sieka 4abd7a5645
exception tracking (#166)
* exception tracking

This PR adds minimal exception tracking to chronos, moving the goalpost
one step further.

In particular, it becomes invalid to raise exceptions from `callSoon`
callbacks: this is critical for writing correct error handling because
there's no reasonable way that a user of chronos can possibly _reason_
about exceptions coming out of there: the event loop will be in an
indeterminite state when the loop is executing an _random_ callback.

As expected, there are several issues in the error handling of chronos:
in particular, it will end up in an inconsistent internal state whenever
the selector loop operations fail, because the internal state update
functions are not written in an exception-safe way. This PR turns this
into a Defect, which probably is not the optimal way of handling things
- expect more work to be done here.

Some API have no way of reporting back errors to callers - for example,
when something fails in the accept loop, there's not much it can do, and
no way to report it back to the user of the API - this has been fixed
with the new accept flow - the old one should be deprecated.

Finally, there is information loss in the API: in composite operations
like `poll` and `waitFor` there's no way to differentiate internal
errors from user-level errors originating from callbacks.

* store `CatchableError` in future
* annotate proc's with correct raises information
* `selectors2` to avoid non-CatchableError IOSelectorsException
* `$` should never raise
* remove unnecessary gcsafe annotations
* fix exceptions leaking out of timer waits
* fix some imports
* functions must signal raising the union of all exceptions across all
platforms to enable cross-platform code
* switch to unittest2
* add `selectors2` which supercedes the std library version and fixes
several exception handling issues in there

* fixes

* docs, platform-independent eh specifiers for some functions

* add feature flag for strict exception mode

also bump version to 3.0.0 - _most_ existing code should be compatible
with this version of exception handling but some things might need
fixing - callbacks, existing raises specifications etc.

* fix AsyncCheck for non-void T
2021-03-24 10:08:33 +01:00

89 lines
2.6 KiB
Nim

# Chronos Test Suite
# (c) Copyright 2018-Present
# Status Research & Development GmbH
#
# Licensed under either of
# Apache License, version 2.0, (LICENSE-APACHEv2)
# MIT license (LICENSE-MIT)
import std/os
import unittest2
import ../chronos, ../chronos/timer
when defined(nimHasUsed): {.used.}
suite "Asynchronous timers & steps test suite":
const TimersCount = 10
proc timeWorker(time: Duration): Future[Duration] {.async.} =
var st = Moment.now()
await sleepAsync(time)
var et = Moment.now()
result = et - st
proc waitAll[T](futs: seq[Future[T]]): Future[void] =
var counter = len(futs)
var retFuture = newFuture[void]("waitAll")
proc cb(udata: pointer) =
dec(counter)
if counter == 0:
retFuture.complete()
for fut in futs:
fut.addCallback(cb)
return retFuture
proc test(timeout: Duration): Future[Duration] {.async.} =
var workers = newSeq[Future[Duration]](TimersCount)
for i in 0..<TimersCount:
workers[i] = timeWorker(timeout)
await waitAll(workers)
var sum: Duration
for i in 0..<TimersCount:
var time = workers[i].read()
sum = sum + time
result = sum div 10'i64
proc testTimer(): bool =
let a = Moment.now()
waitFor(sleepAsync(1000.milliseconds))
let b = Moment.now()
let d = b - a
result = (d >= 1000.milliseconds) and (d <= 3000.milliseconds)
if not result:
echo d
test "Timer reliability test [" & asyncTimer & "]":
check testTimer() == true
test $TimersCount & " timers with 10ms timeout":
var res = waitFor(test(10.milliseconds))
check (res >= 10.milliseconds) and (res <= 100.milliseconds)
test $TimersCount & " timers with 100ms timeout":
var res = waitFor(test(100.milliseconds))
check (res >= 100.milliseconds) and (res <= 1000.milliseconds)
test $TimersCount & " timers with 1000ms timeout":
var res = waitFor(test(1000.milliseconds))
check (res >= 1000.milliseconds) and (res <= 5000.milliseconds)
test "Asynchronous steps test":
var futn1 = stepsAsync(-1)
var fut0 = stepsAsync(0)
var fut1 = stepsAsync(1)
var fut2 = stepsAsync(2)
var fut3 = stepsAsync(3)
check:
futn1.completed() == true
fut0.completed() == true
fut1.completed() == false
fut2.completed() == false
fut3.completed() == false
poll()
check:
fut1.completed() == true
fut2.completed() == false
fut3.completed() == false
poll()
check:
fut2.completed() == true
fut3.completed() == false
poll()
check:
fut3.completed() == true