tests/test-worker.t

bundle: introduce an higher level function to write bundle on disk

The current function ('writebundle') is focussing on getting an existing
changegroup to disk. It is no easy ways to includes more part in the generated
bundle2. So we introduce a slightly higher level function that is fed the
'outgoing' object (that defines the bundled spec) and the bundlespec parameters
(to control the changegroup generation and inclusion of other parts).

This is creating the third logic dedicated to create a consistent bundle2 (the
other 2 are the push code and the getbundle code). We should probably reconcile
them at some points but they all takes different types of input. So we need to
introduce an intermediate "object" that each different input could be converted
to. Such unified "bundle2 specification" could be fed to some unified code.

We start by having the `hg bundle` related code on its own to helps defines its
specific needs first. Once the common and specific parts of each logic will be
known we can start unification.

Test UI worker interaction

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