test: add test-transaction-rollback-on-sigpipe.t demonstrating py3 regression
When an hg push is interrupted with C-c, the remote [hg serve] command
receives SIGPIPE.
If a pretxnchangegroup hook fails, the remote hg then tries to
rollback the transaction. It begins by printing "transaction
abort!\n". This returns EPIPE, but ui.py ignores that error.
In python3 (but not python2), this "transaction abort!\n" message
stays in a buffer, so future flushes of stderr will try to print the
message again, and so those flushes will also hit EPIPE.
This test demonstrates such a case where this EPIPE causes the
transaction rollback to fail, leaving behind an abandoned transaction.
Differential Revision: https://phab.mercurial-scm.org/D9151
Test UI worker interaction
$ cat > t.py <<EOF
> from __future__ import absolute_import, print_function
> import sys
> import time
> from mercurial import (
> error,
> registrar,
> ui as uimod,
> worker,
> )
> sys.unraisablehook = lambda x: None
> 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)'
raise error.Abort(b'known exception')
mercurial.error.Abort: known exception (py3 !)
Abort: known exception (no-py3 !)
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 sys
> import time
> sys.unraisablehook = lambda x: None
> 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]
Do not crash on partially read result
$ cat > $TESTTMP/detecttruncated.py <<EOF
> from __future__ import absolute_import
> import os
> import sys
> import time
> sys.unraisablehook = lambda x: None
> oldwrite = os.write
> def splitwrite(fd, string):
> ret = oldwrite(fd, string[:9])
> if ret == 9:
> time.sleep(0.1)
> ret += oldwrite(fd, string[9:])
> return ret
> os.write = splitwrite
> EOF
$ hg --config "extensions.t=$abspath" --config worker.numcpus=8 --config \
> "extensions.d=$TESTTMP/detecttruncated.py" test 100000.0
start
run
run
run
run
run
run
run
run
done
#endif