tests/test-worker.t

rust: hooking into Python code

We introduce a new class called 'rustlazyancestors'
in the ancestors module, which is used only if
parsers.rustlazyancestors does exist.

The implementation of __contains__ stays unchanged,
but is now backed by the Rust iterator. It would
probably be a good candidate for further development,
though, as it is mostly looping, and duplicates the
'seen' set.

The Rust code could be further optimized, however it already
gives rise to performance improvements:

median timing from hg perfancestors:
- on pypy:
    before: 0.077566s
    after:  0.016676s -79%
- on mozilla central:
    before: 0.190037s
    after:  0.082225s -58%
- on a private repository (about one million revisions):
    before: 0.567085s
    after:  0.108816s -80%
- on another private repository (about 400 000 revisions):
    before: 1.440918s
    after:  0.290116s -80%

median timing for hg perfbranchmap base
- on pypy:
    before:  1.383413s
    after:   0.507993s -63%
- on mozilla central:
    before:  2.821940s
    after:   1.258902s -55%
- on a private repository (about one million revisions):
    before: 77.065076s
    after:   16.158475s -80%
- on another private repository (about 401 000 revisions):
    before:  7.835503s
    after:   3.545331s -54%

Test UI worker interaction

  $ cat > t.py <<EOF
  > from __future__ import absolute_import, print_function
  > import time
  > from mercurial import (
  >     error,
  >     registrar,
  >     ui as uimod,
  >     worker,
  > )
  > def abort(ui, args):
  >     if args[0] == 0:
  >         # by first worker for test stability
  >         raise error.Abort(b'known exception')
  >     return runme(ui, [])
  > def exc(ui, args):
  >     if args[0] == 0:
  >         # by first worker for test stability
  >         raise Exception('unknown exception')
  >     return runme(ui, [])
  > def runme(ui, args):
  >     for arg in args:
  >         ui.status(b'run\n')
  >         yield 1, arg
  >     time.sleep(0.1) # easier to trigger killworkers code path
  > functable = {
  >     b'abort': abort,
  >     b'exc': exc,
  >     b'runme': runme,
  > }
  > cmdtable = {}
  > command = registrar.command(cmdtable)
  > @command(b'test', [], b'hg test [COST] [FUNC]')
  > def t(ui, repo, cost=1.0, func=b'runme'):
  >     cost = float(cost)
  >     func = functable[func]
  >     ui.status(b'start\n')
  >     runs = worker.worker(ui, cost, func, (ui,), range(8))
  >     for n, i in runs:
  >         pass
  >     ui.status(b'done\n')
  > EOF
  $ abspath=`pwd`/t.py
  $ hg init

Run tests with worker enable by forcing a heigh cost

  $ hg --config "extensions.t=$abspath" test 100000.0
  start
  run
  run
  run
  run
  run
  run
  run
  run
  done

Run tests without worker by forcing a low cost

  $ hg --config "extensions.t=$abspath" test 0.0000001
  start
  run
  run
  run
  run
  run
  run
  run
  run
  done

#if no-windows

Known exception should be caught, but printed if --traceback is enabled

  $ hg --config "extensions.t=$abspath" --config 'worker.numcpus=8' \
  > test 100000.0 abort 2>&1
  start
  abort: known exception
  [255]

  $ hg --config "extensions.t=$abspath" --config 'worker.numcpus=8' \
  > test 100000.0 abort --traceback 2>&1 | egrep '^(SystemExit|Abort)'
  Abort: known exception
  SystemExit: 255

Traceback must be printed for unknown exceptions

  $ hg --config "extensions.t=$abspath" --config 'worker.numcpus=8' \
  > test 100000.0 exc 2>&1 | grep '^Exception'
  Exception: unknown exception

Workers should not do cleanups in all cases

  $ cat > $TESTTMP/detectcleanup.py <<EOF
  > from __future__ import absolute_import
  > import atexit
  > import os
  > import time
  > oldfork = os.fork
  > count = 0
  > parentpid = os.getpid()
  > def delayedfork():
  >     global count
  >     count += 1
  >     pid = oldfork()
  >     # make it easier to test SIGTERM hitting other workers when they have
  >     # not set up error handling yet.
  >     if count > 1 and pid == 0:
  >         time.sleep(0.1)
  >     return pid
  > os.fork = delayedfork
  > def cleanup():
  >     if os.getpid() != parentpid:
  >         os.write(1, 'should never happen\n')
  > atexit.register(cleanup)
  > EOF

  $ hg --config "extensions.t=$abspath" --config worker.numcpus=8 --config \
  > "extensions.d=$TESTTMP/detectcleanup.py" test 100000 abort
  start
  abort: known exception
  [255]

#endif