tests/test-nointerrupt.t

worker: avoid potential partial write of pickled data

Previously, the code wrote the pickled data using os.write(). However,
os.write() can write less bytes than passed to it. To trigger the problem, the
pickled data had to be larger than 2147479552 bytes on my system.

Instead, open a file object and pass it to pickle.dump(). This also has the
advantage that it doesn’t buffer the whole pickled data in memory.

Note that the opened file must be buffered because pickle doesn’t support
unbuffered streams because unbuffered streams’ write() method might write less
bytes than passed to it (like os.write()) but pickle.dump() relies on that all
bytes are written (see https://github.com/python/cpython/issues/93050).

The side effect of using a file object and a with statement is that wfd is
explicitly closed now while it seems like before it was implicitly closed by
process exit.

#require no-windows no-rhg

XXX-RHG this test hangs if `hg` is really `rhg`. This was hidden by the use of
`alias hg=rhg` by run-tests.py. With such alias removed, this test is revealed
buggy. This need to be resolved sooner than later.

Dummy extension simulating unsafe long running command
  $ SYNC_FILE="$TESTTMP/sync-file"
  $ export SYNC_FILE
  $ DONE_FILE="$TESTTMP/done-file"
  $ export DONE_FILE
  $ 
  $ cat > wait_ext.py <<EOF
  > import os
  > import time
  > 
  > from mercurial.i18n import _
  > from mercurial import registrar
  > from mercurial import testing
  > 
  > cmdtable = {}
  > command = registrar.command(cmdtable)
  > 
  > @command(b'wait-signal', [], _(b'SYNC_FILE DONE_FILE'), norepo=True)
  > def sleep(ui, sync_file=b"$SYNC_FILE", done_file=b"$DONE_FILE", **opts):
  >     start = time.time()
  >     with ui.uninterruptible():
  >         testing.write_file(sync_file, b'%d' % os.getpid())
  >         testing.wait_file(done_file)
  >         # make sure we get rescheduled and the signal get a chance to be handled
  >         time.sleep(0.1)
  >         ui.warn(b"end of unsafe operation\n")
  >     ui.warn(b"%d second(s) passed\n" % int(time.time() - start))
  > EOF

  $ cat > send-signal.sh << EOF
  > #!/bin/sh
  > SIG=\$1
  > if [ -z "\$SIG" ]; then
  >    echo "send-signal.sh requires one argument" >&2
  >    exit 1
  > fi
  > "$RUNTESTDIR/testlib/wait-on-file" 10 "$SYNC_FILE" || exit 2
  > kill -s \$SIG \`cat "$SYNC_FILE"\`
  > sleep 1
  > touch "$DONE_FILE"
  > EOF

#if no-windows
  $ chmod +x send-signal.sh
#endif

Kludge to emulate timeout(1) which is not generally available.

Set up repository
  $ hg init repo
  $ cd repo
  $ cat >> $HGRCPATH << EOF
  > [extensions]
  > wait_ext = $TESTTMP/wait_ext.py
  > EOF


Test ctrl-c
  $ rm -f $SYNC_FILE $DONE_FILE
  $ sh -c "../send-signal.sh INT" &
  $ hg wait-signal
  interrupted!
  [255]

  $ cat >> $HGRCPATH << EOF
  > [experimental]
  > nointerrupt = yes
  > EOF

  $ rm -f $SYNC_FILE $DONE_FILE
  $ sh -c "../send-signal.sh INT" &
  $ hg wait-signal
  interrupted!
  [255]

  $ cat >> $HGRCPATH << EOF
  > [experimental]
  > nointerrupt-interactiveonly = False
  > EOF

  $ rm -f $SYNC_FILE $DONE_FILE
  $ sh -c "../send-signal.sh INT" &
  $ hg wait-signal
  shutting down cleanly
  press ^C again to terminate immediately (dangerous)
  end of unsafe operation
  interrupted!
  [255]