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tractor/tractor/_debug.py

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3.3 KiB
Python

"""
Multi-core debugging for da peeps!
"""
import pdb
import sys
import tty
from functools import partial
from typing import Awaitable, Tuple
from async_generator import aclosing
import tractor
import trio
from .log import get_logger
log = get_logger(__name__)
__all__ = ['breakpoint', 'post_mortem']
# TODO: is there some way to determine this programatically?
_pdb_exit_patterns = tuple(
str.encode(patt + "\n") for patt in ('c', 'cont', 'continue', 'q', 'quit')
)
def subactoruid2proc(
actor: 'Actor', # noqa
uid: Tuple[str, str]
) -> trio.Process:
n = actor._actoruid2nursery[uid]
_, proc, _ = n._children[uid]
return proc
async def _hijack_stdin_relay_to_child(
subactor_uid: Tuple[str, str]
) -> None:
actor = tractor.current_actor()
proc = subactoruid2proc(actor, subactor_uid)
# nlb = []
async def hijack_stdin():
log.info(f"Hijacking stdin from {actor.uid}")
# try:
# # disable cooked mode
# fd = sys.stdin.fileno()
# old = tty.tcgetattr(fd)
# tty.setcbreak(fd)
# trap std in and relay to subproc
async_stdin = trio.wrap_file(sys.stdin)
async with aclosing(async_stdin):
# while True:
async for msg in async_stdin:
log.trace(f"Stdin input:\n{msg}")
# nlb.append(msg)
# encode to bytes
bmsg = str.encode(msg)
# relay bytes to subproc over pipe
await proc.stdin.send_all(bmsg)
# line = str.encode(''.join(nlb))
# print(line)
if bmsg in _pdb_exit_patterns:
log.info("Closing stdin hijack")
break
# finally:
# tty.tcsetattr(fd, tty.TCSAFLUSH, old)
# schedule hijacking in root scope
actor._root_nursery.start_soon(hijack_stdin)
# XXX: We only make this sync in case someone wants to
# overload the ``breakpoint()`` built-in.
def _breakpoint(debug_func) -> Awaitable[None]:
"""``tractor`` breakpoint entry for engaging pdb machinery
in subactors.
"""
actor = tractor.current_actor()
async def wait_for_parent_stdin_hijack():
log.debug('Breakpoint engaged!')
# TODO: need a more robust check for the "root" actor
if actor._parent_chan:
async with tractor._portal.open_portal(
actor._parent_chan,
start_msg_loop=False,
) as portal:
# with trio.fail_after(1):
await portal.run(
'tractor._debug',
'_hijack_stdin_relay_to_child',
subactor_uid=actor.uid,
)
# block here one frame up where ``breakpoint()``
# was awaited and begin handling stdin
debug_func(actor)
# this must be awaited by caller
return wait_for_parent_stdin_hijack()
def _set_trace(actor):
pdb.set_trace(
header=f"\nAttaching pdb to actor: {actor.uid}\n",
# start 2 levels up
frame=sys._getframe().f_back.f_back,
)
breakpoint = partial(
_breakpoint,
_set_trace,
)
def _post_mortem(actor):
log.error(f"\nAttaching to pdb in crashed actor: {actor.uid}\n")
pdb.post_mortem()
post_mortem = partial(
_breakpoint,
_post_mortem,
)