def run(self):
# os.close gets called in finally,
# which sometimes is executed while the process is shutting down already.
# It happens that the Python interpreter has already cleaned up at this point
# and "os" resolves to None, leading to an AttributeError.
# Thus we keep our own reference to this function.
# (Should not happen anymore since this is no longer a daemon thread,
# but should not hurt anyway.)
close = os.close
try:
# In an eventfd, there are always 8 bytes for the event number.
# We just do a blocking read to wait for the event.
_ = os.read(self._efd, 8)
# If read returned, this means the kernel sent us an event.
# It does so either on OOM or if the cgroup is removed.
if not self._finished.is_set():
self._callback("memory")
logging.debug(
"Killing process %s due to out-of-memory event from kernel.",
self._pid_to_kill,
)
util.kill_process(self._pid_to_kill)
# Also kill all children of subprocesses directly.
with open(os.path.join(self._cgroups[MEMORY], "tasks"), "rt") as tasks:
for task in tasks:
util.kill_process(int(task))
# We now need to increase the memory limit of this cgroup
# to give the process a chance to terminate
self._reset_memory_limit("memory.memsw.limit_in_bytes")
self._reset_memory_limit("memory.limit_in_bytes")
finally:
close(self._efd)
def kill_all_tasks_in_cgroup(cgroup, ensure_empty=True):
tasksFile = os.path.join(cgroup, "tasks")
i = 0
while True:
i += 1
# TODO We can probably remove this loop over signals and just send
# SIGKILL. We added this loop when killing sub-processes was not reliable
# and we did not know why, but now it is reliable.
for sig in [signal.SIGKILL, signal.SIGINT, signal.SIGTERM]:
with open(tasksFile, "rt") as tasks:
task = None
for task in tasks:
task = task.strip()
if i > 1:
logging.warning(
"Run has left-over process with pid %s "
"in cgroup %s, sending signal %s (try %s).",
task,
cgroup,
sig,
i,
)
util.kill_process(int(task), sig)
if task is None or not ensure_empty:
return # No process was hanging, exit
# wait for the process to exit, this might take some time
time.sleep(i * 0.5)
def stop(self):
self.PROCESS_KILLED = True
with self.SUB_PROCESS_PIDS_LOCK:
for pid in self.SUB_PROCESS_PIDS:
logging.warning("Killing process %s forcefully.", pid)
try:
util.kill_process(pid)
except EnvironmentError as e:
# May fail due to race conditions
logging.debug(e)
def _check_limit(self, files_count, files_size):
if self._files_count_limit and files_count > self._files_count_limit:
reason = "files-count"
elif self._files_size_limit and files_size > self._files_size_limit:
reason = "files-size"
else:
return None
self._callback(reason)
logging.debug(
"Killing process %d due to %s limit (%d files with %d bytes).",
self._pid_to_kill,
reason,
files_count,
files_size,
)
util.kill_process(self._pid_to_kill)
return reason
def kill_all_tasks_in_cgroup(cgroup):
tasksFile = os.path.join(cgroup, "tasks")
freezer_file = os.path.join(cgroup, "freezer.state")
def try_write_to_freezer(content):
try:
util.write_file(content, freezer_file)
except IOError:
pass # expected if freezer not enabled, we try killing without it
i = 0
while True:
i += 1
# TODO We can probably remove this loop over signals and just send
# SIGKILL. We added this loop when killing sub-processes was not reliable
# and we did not know why, but now it is reliable.
for sig in [signal.SIGKILL, signal.SIGINT, signal.SIGTERM]:
try_write_to_freezer("FROZEN")
with open(tasksFile, "rt") as tasks:
task = None
for task in tasks:
task = task.strip()
if i > 1:
logging.warning(
"Run has left-over process with pid %s "
"in cgroup %s, sending signal %s (try %s).",
task,
cgroup,
sig,
i,
)
util.kill_process(int(task), sig)
if task is None:
return # No process was hanging, exit
try_write_to_freezer("THAWED")
# wait for the process to exit, this might take some time
time.sleep(i * 0.5)
