Always undo SIGINT overrides, cancel detached children

Ensure that even when `pdb` resumption methods are called during a crash
where `trio`'s runtime has already terminated (eg. `Event.set()` will
raise) we always revert our sigint handler to the original. Further
inside the handler if we hit a case where a child is in debug and
(thinks it) has the global pdb lock, if it has no IPC connection to
a parent, simply presume tty sync-coordination is now lost and cancel
the child immediately.
signint_saviour
Tyler Goodlet 2022-06-26 13:41:32 -04:00
parent 2f5a6049a4
commit f07e9dbb2f
1 changed files with 47 additions and 23 deletions

View File

@ -41,6 +41,7 @@ from .log import get_logger
from ._discovery import get_root
from ._state import is_root_process, debug_mode
from ._exceptions import is_multi_cancelled
from ._ipc import Channel
try:
@ -396,6 +397,10 @@ def mk_mpdb() -> tuple[MultiActorPdb, Callable]:
signal.SIGINT,
partial(shield_sigint, pdb_obj=pdb),
)
# XXX: These are the important flags mentioned in
# https://github.com/python-trio/trio/issues/1155
# which resolve the traceback spews to console.
pdb.allow_kbdint = True
pdb.nosigint = True
@ -464,11 +469,15 @@ async def _breakpoint(
_local_task_in_debug = task_name
def child_release_hook():
# _local_task_in_debug = None
_local_pdb_complete.set()
# restore original sigint handler
undo_sigint()
try:
# sometimes the ``trio`` might already be termianated in
# which case this call will raise.
_local_pdb_complete.set()
finally:
# restore original sigint handler
undo_sigint()
# should always be cleared in the hijack hook aboved right?
# _local_task_in_debug = None
# assign unlock callback for debugger teardown hooks
# _pdb_release_hook = _local_pdb_complete.set
@ -539,10 +548,14 @@ async def _breakpoint(
_global_actor_in_debug = None
_local_task_in_debug = None
_local_pdb_complete.set()
# restore original sigint handler
undo_sigint()
try:
# sometimes the ``trio`` might already be termianated in
# which case this call will raise.
_local_pdb_complete.set()
finally:
# restore original sigint handler
undo_sigint()
_pdb_release_hook = teardown
@ -600,7 +613,21 @@ def shield_sigint(
actor = tractor.current_actor()
def do_cancel():
# If we haven't tried to cancel the runtime then do that instead
# of raising a KBI (which may non-gracefully destroy
# a ``trio.run()``).
if not actor._cancel_called:
actor.cancel_soon()
# If the runtime is already cancelled it likely means the user
# hit ctrl-c again because teardown didn't full take place in
# which case we do the "hard" raising of a local KBI.
else:
raise KeyboardInterrupt
any_connected = False
if uid_in_debug is not None:
# try to see if the supposed (sub)actor in debug still
# has an active connection to *this* actor, and if not
@ -616,6 +643,7 @@ def shield_sigint(
f'{uid_in_debug}\n'
'Allowing SIGINT propagation..'
)
return do_cancel()
# root actor branch that reports whether or not a child
# has locked debugger.
@ -644,6 +672,16 @@ def shield_sigint(
elif (
not is_root_process()
):
chan: Channel = actor._parent_chan
if not chan or not chan.connected():
log.warning(
'A global actor reported to be in debug '
'but no connection exists for its parent:\n'
f'{uid_in_debug}\n'
'Allowing SIGINT propagation..'
)
return do_cancel()
task = _local_task_in_debug
if task:
log.pdb(
@ -659,20 +697,6 @@ def shield_sigint(
"Ignoring SIGINT since debug mode is enabled"
)
# noone has the debugger so raise KBI
else:
# If we haven't tried to cancel the runtime then do that instead
# of raising a KBI (which may non-gracefully destroy
# a ``trio.run()``).
if not actor._cancel_called:
actor.cancel_soon()
# If the runtime is already cancelled it likely means the user
# hit ctrl-c again because teardown didn't full take place in
# which case we do the "hard" raising of a local KBI.
else:
raise KeyboardInterrupt
# maybe redraw/print last REPL output to console
if pdb_obj:
@ -709,7 +733,7 @@ def _set_trace(
# start 2 levels up in user code
frame: FrameType = sys._getframe()
if frame:
frame = frame.f_back.f_back # type: ignore
frame = frame.f_back # type: ignore
if pdb and actor is not None:
log.pdb(f"\nAttaching pdb to actor: {actor.uid}\n")