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Docs and comments tidying

ctx_debugger
Tyler Goodlet 2021-08-01 10:43:21 -04:00
parent f173012fea
commit 674fbbc6b3
6 changed files with 42 additions and 55 deletions
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7
examples/debugging/fast_error_in_root_after_spawn.py
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@ -1,8 +1,9 @@
'''
fast fail test with a context.
ensure the partially initialized sub-actor process
Fast fail test with a context.
Ensure the partially initialized sub-actor process
doesn't cause a hang on error/cancel of the parent
nrusery.
nursery.
'''
import trio

6
examples/debugging/root_timeout_while_child_crashed.py
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@ -20,9 +20,9 @@ async def main():
# spawn both actors
portal = await n.run_in_actor(key_error)
# XXX: originally a bug causes by this
# where root would enter debugger even
# though child should have it locked.
# XXX: originally a bug caused by this is where root would enter
# the debugger and clobber the tty used by the repl even though
# child should have it locked.
with trio.fail_after(1):
await trio.Event().wait()

13
tests/test_debugger.py
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@ -325,7 +325,7 @@ def test_multi_daemon_subactors(spawn, loglevel):
# NOTE: previously since we did not have clobber prevention
# in the root actor this final resume could result in the debugger
# tearing down since both child actors would be cancelled and it was
# unlikely that `bp_forever` would re-acquire the tty loack again.
# unlikely that `bp_forever` would re-acquire the tty lock again.
# Now, we should have a final resumption in the root plus a possible
# second entry by `bp_forever`.
@ -335,7 +335,7 @@ def test_multi_daemon_subactors(spawn, loglevel):
assert next_msg in before
# XXX: hoorayy the root clobering the child here was fixed!
# XXX: hooray the root clobbering the child here was fixed!
# IMO, this demonstrates the true power of SC system design.
# now the root actor won't clobber the bp_forever child
@ -412,9 +412,9 @@ def test_multi_subactors_root_errors(spawn):
def test_multi_nested_subactors_error_through_nurseries(spawn):
"""Verify deeply nested actors that error trigger debugger entries
at each actor nurserly (level) all the way up the tree.
"""
# NOTE: previously, inside this script was a a bug where if the
"""
# NOTE: previously, inside this script was a bug where if the
# parent errors before a 2-levels-lower actor has released the lock,
# the parent tries to cancel it but it's stuck in the debugger?
# A test (below) has now been added to explicitly verify this is
@ -422,9 +422,6 @@ def test_multi_nested_subactors_error_through_nurseries(spawn):
child = spawn('multi_nested_subactors_error_up_through_nurseries')
# startup time can be iffy
# time.sleep(1)
for i in range(12):
try:
child.expect(r"\(Pdb\+\+\)")
@ -502,7 +499,7 @@ def test_root_nursery_cancels_before_child_releases_tty_lock(
child.expect(pexpect.EOF)
break
except pexpect.exceptions.TIMEOUT:
print('child was ablel to grab tty lock again?')
print('child was able to grab tty lock again?')
if not timed_out_early:

62
tractor/_debug.py
View File

@ -66,7 +66,7 @@ class PdbwTeardown(pdbpp.Pdb):
# override the pdbpp config with our coolio one
DefaultConfig = TractorConfig
# TODO: figure out how to dissallow recursive .set_trace() entry
# TODO: figure out how to disallow recursive .set_trace() entry
# since that'll cause deadlock for us.
def set_continue(self):
try:
@ -125,9 +125,14 @@ class PdbwTeardown(pdbpp.Pdb):
@asynccontextmanager
async def _acquire_debug_lock(
uid: Tuple[str, str]
) -> AsyncIterator[trio.StrictFIFOLock]:
'''Acquire a actor local FIFO lock meant to mutex entry to a local
debugger entry point to avoid tty clobbering a global root process.
'''Acquire a root-actor local FIFO lock which tracks mutex access of
the process tree's global debugger breakpoint.
This lock avoids tty clobbering (by preventing multiple processes
reading from stdstreams) and ensures multi-actor, sequential access
to the ``pdb`` repl.
'''
global _debug_lock, _global_actor_in_debug, _no_remote_has_tty
@ -153,21 +158,18 @@ async def _acquire_debug_lock(
we_acquired = True
await _debug_lock.acquire()
# we_acquired = True
_global_actor_in_debug = uid
log.debug(f"TTY lock acquired, remote task: {task_name}:{uid}")
# NOTE: critical section!
# this yield is unshielded.
# IF we received a cancel during the shielded lock
# entry of some next-in-queue requesting task,
# then the resumption here will result in that
# Cancelled being raised to our caller below!
# NOTE: critical section: this yield is unshielded!
# in this case the finally below should trigger
# and the surrounding calle side context should cancel
# normally relaying back to the caller.
# IF we received a cancel during the shielded lock entry of some
# next-in-queue requesting task, then the resumption here will
# result in that ``trio.Cancelled`` being raised to our caller
# (likely from ``_hijack_stdin_for_child()`` below)! In
# this case the ``finally:`` below should trigger and the
# surrounding caller side context should cancel normally
# relaying back to the caller.
yield _debug_lock
@ -194,19 +196,8 @@ async def _acquire_debug_lock(
log.debug(f"TTY lock released, remote task: {task_name}:{uid}")
# @contextmanager
# def _disable_sigint():
# try:
# # disable sigint handling while in debug
# prior_handler = signal.signal(signal.SIGINT, handler)
# yield
# finally:
# # restore SIGINT handling
# signal.signal(signal.SIGINT, prior_handler)
@tractor.context
async def _hijack_stdin_relay_to_child(
async def _hijack_stdin_for_child(
ctx: tractor.Context,
subactor_uid: Tuple[str, str]
@ -235,8 +226,7 @@ async def _hijack_stdin_relay_to_child(
# indicate to child that we've locked stdio
await ctx.started('Locked')
log.pdb( # type: ignore
f"Actor {subactor_uid} ACQUIRED stdin hijack lock")
log.pdb(f"Actor {subactor_uid} ACQUIRED stdin hijack lock")
# wait for unlock pdb by child
async with ctx.open_stream() as stream:
@ -245,14 +235,13 @@ async def _hijack_stdin_relay_to_child(
except trio.BrokenResourceError:
# XXX: there may be a race with the portal teardown
# with the calling actor which we can safely ignore
# the alternative would be sending an ack message
# with the calling actor which we can safely ignore.
# The alternative would be sending an ack message
# and allowing the client to wait for us to teardown
# first?
pass
log.debug(
f"TTY lock released, remote task: {task_name}:{subactor_uid}")
log.debug(f"TTY lock released, remote task: {task_name}:{subactor_uid}")
return "pdb_unlock_complete"
@ -299,7 +288,7 @@ async def _breakpoint(
# this syncs to child's ``Context.started()`` call.
async with portal.open_context(
tractor._debug._hijack_stdin_relay_to_child,
tractor._debug._hijack_stdin_for_child,
subactor_uid=actor.uid,
) as (ctx, val):
@ -377,8 +366,7 @@ async def _breakpoint(
# may have the tty locked prior
global _debug_lock
# TODO: wait, what about multiple root tasks acquiring
# it though.. shrug?
# TODO: wait, what about multiple root tasks acquiring it though?
# root process (us) already has it; ignore
if _global_actor_in_debug == actor.uid:
return
@ -408,8 +396,8 @@ async def _breakpoint(
_pdb_release_hook = teardown
# block here one (at the appropriate frame *up* where
# ``breakpoint()`` was awaited and begin handling stdio
# block here one (at the appropriate frame *up*) where
# ``breakpoint()`` was awaited and begin handling stdio.
log.debug("Entering the synchronous world of pdb")
debug_func(actor)

2
tractor/_root.py
View File

@ -174,7 +174,7 @@ async def open_root_actor(
yield actor
except (Exception, trio.MultiError) as err:
# with trio.CancelScope(shield=True):
entered = await _debug._maybe_enter_pm(err)
if not entered:

7
tractor/_trionics.py
View File

@ -283,9 +283,10 @@ async def _open_and_supervise_one_cancels_all_nursery(
if is_root_process():
log.exception(f"we're root with {err}")
# wait to see if a sub-actor task
# will be scheduled and grab the tty
# lock on the next tick
# TODO: could this make things more deterministic?
# wait to see if a sub-actor task will be
# scheduled and grab the tty lock on the next
# tick?
# await trio.testing.wait_all_tasks_blocked()
debug_complete = _debug._no_remote_has_tty