test: remove `sleep` usage in `test-nointerrupt.t` (issue6271)

We move from sleep based synchronisation to file creation based synchronisation.

Sleeps is the path to the dark side.
Sleeps leads to flakiness.
Flakiness leads to anger.
Anger leads to hate.
Hate leads to suffering.

Differential Revision: https://phab.mercurial-scm.org/D11205

tests/test-nointerrupt.t

@@ -5,85 +5,87 b' XXX-RHG this test hangs if `hg` is reall'
 buggy. This need to be resolved sooner than later.
 
 Dummy extension simulating unsafe long running command
-  $ cat > sleepext.py <<EOF
-  > import itertools
+  $ 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'sleep', [], _(b'TIME'), norepo=True)
-  > def sleep(ui, sleeptime=b"1", **opts):
+  > @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():
-  >         for _i in itertools.repeat(None, int(sleeptime)):
-  >             time.sleep(1)
+  >         testing.write_file(sync_file, b'%d' % os.getpid())
+  >         testing.wait_file(done_file)
   >         ui.warn(b"end of unsafe operation\n")
-  >     ui.warn(b"%s second(s) passed\n" % sleeptime)
+  >     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 "$SYNC_FILE"\`
+  > touch "$DONE_FILE"
+  > EOF
+
+#if no-windows
+  $ chmod +x send-signal.sh
+#endif
+
 Kludge to emulate timeout(1) which is not generally available.
-  $ cat > timeout.py <<EOF
-  > from __future__ import print_function
-  > import argparse
-  > import signal
-  > import subprocess
-  > import sys
-  > import time
-  > 
-  > ap = argparse.ArgumentParser()
-  > ap.add_argument('-s', nargs=1, default='SIGTERM')
-  > ap.add_argument('duration', nargs=1, type=int)
-  > ap.add_argument('argv', nargs='*')
-  > opts = ap.parse_args()
-  > try:
-  >     sig = int(opts.s[0])
-  > except ValueError:
-  >     sname = opts.s[0]
-  >     if not sname.startswith('SIG'):
-  >         sname = 'SIG' + sname
-  >     sig = getattr(signal, sname)
-  > proc = subprocess.Popen(opts.argv)
-  > time.sleep(opts.duration[0])
-  > proc.poll()
-  > if proc.returncode is None:
-  >     proc.send_signal(sig)
-  >     proc.wait()
-  >     sys.exit(124)
-  > EOF
 
 Set up repository
   $ hg init repo
   $ cd repo
   $ cat >> $HGRCPATH << EOF
   > [extensions]
-  > sleepext = ../sleepext.py
+  > wait_ext = $TESTTMP/wait_ext.py
   > EOF
 
+
 Test ctrl-c
-  $ "$PYTHON" $TESTTMP/timeout.py -s INT 1 hg sleep 2
+  $ rm -f $SYNC_FILE $DONE_FILE
+  $ sh -c "../send-signal.sh INT" &
+  $ hg wait-signal
   interrupted!
-  [124]
+  [255]
 
   $ cat >> $HGRCPATH << EOF
   > [experimental]
   > nointerrupt = yes
   > EOF
 
-  $ "$PYTHON" $TESTTMP/timeout.py -s INT 1 hg sleep 2
+  $ rm -f $SYNC_FILE $DONE_FILE
+  $ sh -c "../send-signal.sh INT" &
+  $ hg wait-signal
   interrupted!
-  [124]
+  [255]
 
   $ cat >> $HGRCPATH << EOF
   > [experimental]
   > nointerrupt-interactiveonly = False
   > EOF
 
-  $ "$PYTHON" $TESTTMP/timeout.py -s INT 1 hg sleep 2
+  $ 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!
-  [124]
+  [255]