Prevent recursive script calls from deadlocking (#67861)

* Prevent recursive script calls from deadlocking

* Address review comments, improve tests

* Tweak comment
This commit is contained in:
Erik Montnemery 2022-03-10 19:28:00 +01:00 committed by GitHub
parent 3d212b868e
commit 65fbcfa0ba
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GPG key ID: 4AEE18F83AFDEB23
2 changed files with 148 additions and 0 deletions

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@ -4,6 +4,7 @@ from __future__ import annotations
import asyncio
from collections.abc import Callable, Sequence
from contextlib import asynccontextmanager, suppress
from contextvars import ContextVar
from datetime import datetime, timedelta
from functools import partial
import itertools
@ -126,6 +127,8 @@ SCRIPT_BREAKPOINT_HIT = "script_breakpoint_hit"
SCRIPT_DEBUG_CONTINUE_STOP = "script_debug_continue_stop_{}_{}"
SCRIPT_DEBUG_CONTINUE_ALL = "script_debug_continue_all"
script_stack_cv: ContextVar[list[int] | None] = ContextVar("script_stack", default=None)
def action_trace_append(variables, path):
"""Append a TraceElement to trace[path]."""
@ -340,6 +343,12 @@ class _ScriptRun:
async def async_run(self) -> None:
"""Run script."""
# Push the script to the script execution stack
if (script_stack := script_stack_cv.get()) is None:
script_stack = []
script_stack_cv.set(script_stack)
script_stack.append(id(self._script))
try:
self._log("Running %s", self._script.running_description)
for self._step, self._action in enumerate(self._script.sequence):
@ -355,6 +364,8 @@ class _ScriptRun:
script_execution_set("error")
raise
finally:
# Pop the script from the script execution stack
script_stack.pop()
self._finish()
async def _async_step(self, log_exceptions):
@ -1218,6 +1229,18 @@ class Script:
else:
variables = cast(dict, run_variables)
# Prevent non-allowed recursive calls which will cause deadlocks when we try to
# stop (restart) or wait for (queued) our own script run.
script_stack = script_stack_cv.get()
if (
self.script_mode in (SCRIPT_MODE_RESTART, SCRIPT_MODE_QUEUED)
and (script_stack := script_stack_cv.get()) is not None
and id(self) in script_stack
):
script_execution_set("disallowed_recursion_detected")
_LOGGER.warning("Disallowed recursion detected")
return
if self.script_mode != SCRIPT_MODE_QUEUED:
cls = _ScriptRun
else:

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@ -27,6 +27,13 @@ from homeassistant.core import (
from homeassistant.exceptions import ServiceNotFound
from homeassistant.helpers import template
from homeassistant.helpers.event import async_track_state_change
from homeassistant.helpers.script import (
SCRIPT_MODE_CHOICES,
SCRIPT_MODE_PARALLEL,
SCRIPT_MODE_QUEUED,
SCRIPT_MODE_RESTART,
SCRIPT_MODE_SINGLE,
)
from homeassistant.helpers.service import async_get_all_descriptions
from homeassistant.setup import async_setup_component
import homeassistant.util.dt as dt_util
@ -790,3 +797,121 @@ async def test_script_restore_last_triggered(hass: HomeAssistant) -> None:
state = hass.states.get("script.last_triggered")
assert state
assert state.attributes["last_triggered"] == time
@pytest.mark.parametrize(
"script_mode,warning_msg",
(
(SCRIPT_MODE_PARALLEL, "Maximum number of runs exceeded"),
(SCRIPT_MODE_QUEUED, "Disallowed recursion detected"),
(SCRIPT_MODE_RESTART, "Disallowed recursion detected"),
(SCRIPT_MODE_SINGLE, "Already running"),
),
)
async def test_recursive_script(hass, script_mode, warning_msg, caplog):
"""Test recursive script calls does not deadlock."""
# Make sure we cover all script modes
assert SCRIPT_MODE_CHOICES == [
SCRIPT_MODE_PARALLEL,
SCRIPT_MODE_QUEUED,
SCRIPT_MODE_RESTART,
SCRIPT_MODE_SINGLE,
]
assert await async_setup_component(
hass,
"script",
{
"script": {
"script1": {
"mode": script_mode,
"sequence": [
{"service": "script.script1"},
{"service": "test.script"},
],
},
}
},
)
service_called = asyncio.Event()
async def async_service_handler(service):
service_called.set()
hass.services.async_register("test", "script", async_service_handler)
hass.states.async_set("input_boolean.test", "on")
hass.states.async_set("input_boolean.test2", "off")
await hass.services.async_call("script", "script1")
await asyncio.wait_for(service_called.wait(), 1)
assert warning_msg in caplog.text
@pytest.mark.parametrize(
"script_mode,warning_msg",
(
(SCRIPT_MODE_PARALLEL, "Maximum number of runs exceeded"),
(SCRIPT_MODE_QUEUED, "Disallowed recursion detected"),
(SCRIPT_MODE_RESTART, "Disallowed recursion detected"),
(SCRIPT_MODE_SINGLE, "Already running"),
),
)
async def test_recursive_script_indirect(hass, script_mode, warning_msg, caplog):
"""Test recursive script calls does not deadlock."""
# Make sure we cover all script modes
assert SCRIPT_MODE_CHOICES == [
SCRIPT_MODE_PARALLEL,
SCRIPT_MODE_QUEUED,
SCRIPT_MODE_RESTART,
SCRIPT_MODE_SINGLE,
]
assert await async_setup_component(
hass,
"script",
{
"script": {
"script1": {
"mode": script_mode,
"sequence": [
{"service": "script.script2"},
],
},
"script2": {
"mode": script_mode,
"sequence": [
{"service": "script.script3"},
],
},
"script3": {
"mode": script_mode,
"sequence": [
{"service": "script.script4"},
],
},
"script4": {
"mode": script_mode,
"sequence": [
{"service": "script.script1"},
{"service": "test.script"},
],
},
}
},
)
service_called = asyncio.Event()
async def async_service_handler(service):
service_called.set()
hass.services.async_register("test", "script", async_service_handler)
hass.states.async_set("input_boolean.test", "on")
hass.states.async_set("input_boolean.test2", "off")
await hass.services.async_call("script", "script1")
await asyncio.wait_for(service_called.wait(), 1)
assert warning_msg in caplog.text