def open(self):
e = "{0} is already open".format(self.name())
assert self.oom_control is None, e
assert self.event_oom is None, e
assert self.event_pressure is None, e
# TODO: CLOEXEC?
logger.debug("%s: open", self.name())
self.oom_control = open(self._oom_control_file_path(), "r")
self.event_oom = linuxfd.eventfd(initval=0, nonBlocking=True)
logger.info("%s: event_oom=%d", self.name(), self.event_oom.fileno())
oom_control_req = "{0} {1}\n".format(self.event_oom.fileno(),
self.oom_control.fileno())
with open(self._evt_control_file_path(), "a") as evt_control:
evt_control.write(oom_control_req)
self.memory_pressure = open(self._memory_pressure_file_path(), "r")
self.event_pressure = linuxfd.eventfd(initval=0, nonBlocking=True)
logger.info("%s: event_pressure=%d", self.name(),
self.event_pressure.fileno())
memory_pressure_req = "{0} {1} critical\n".format(
self.event_pressure.fileno(), self.memory_pressure.fileno())
with open(self._evt_control_file_path(), "a") as evt_control:
evt_control.write(memory_pressure_req)
def main(pid, memory_usage_factor_limit=MEMORY_USAGE_FACTOR_LIMIT):
name = 'MemWatcher'
logger.info(
f'starting {name} for PID {pid} and memory usage factor limit {memory_usage_factor_limit}'
)
efd = linuxfd.eventfd(initval=0, nonBlocking=True)
mfd = open(MEMORY_USAGE_IN_BYTES)
mfd.fileno()
threshold = get_threshold(memory_usage_factor_limit)
with open(CGROUP_EVENT_CONTROL, 'w') as f:
f.write(f'{efd.fileno()} {mfd.fileno()} {threshold}')
epl = select.epoll()
epl.register(efd.fileno(), select.EPOLLIN)
try:
isrunning = True
while isrunning:
events = epl.poll(-1)
for fd, event in events:
if fd == efd.fileno() and event & select.EPOLLIN:
logger.info('event file received update')
logger.info(
f'{name} sent signal to the main process with pid {pid}'
)
efd.read()
os.kill(pid, signal.SIGUSR1)
isrunning = False
finally:
logger.info(f'closing {name}')
epl.unregister(efd.fileno())
epl.close()
def open(self):
e = "{0} is already open".format(self.name())
assert self.oom_control is None, e
assert self.event is None, e
# TODO: CLOEXEC?
logger.debug("%s: open", self.name())
self.oom_control = open(self._oom_control_file_path(), "r")
self.event = linuxfd.eventfd(initval=0, nonBlocking=True)
req = "{0} {1}\n".format(self.event_fileno(),
self.oom_control.fileno())
with open(self._evt_control_file_path(), "w") as evt_control:
evt_control.write(req)
linuxfd is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with linuxfd. If not, see <http://www.gnu.org/licenses/>.
Written in Python V3."""
import linuxfd, signal, pprint, time, tempfile, os
#
# test eventfd
#
efd = linuxfd.eventfd(initval=0, nonBlocking=True)
print("\ntesting eventfd (fd={})".format(efd.fileno()))
for i in range(0, 3):
print(" writing to sempahore")
efd.write()
try:
while True:
value = efd.read()
print(" read '{}' from semaphore".format(value))
except BlockingIOError:
print(" semaphore exhausted")
print("\ntesting eventfd (fd={}, mode: counting)".format(efd.fileno()))
efd = linuxfd.eventfd(initval=0, semaphore=True, nonBlocking=True)
for i in range(0, 3):
print(" writing to sempahore")
import sys
import linuxfd
buffersize = 256
efd=linuxfd.eventfd(0,0) #creates a event file descriptor efd for event notifications
cfd=open(sys.argv[1], mode='w') #opens the cgroup.event_control file
ofd=open(sys.argv[2], mode='r') #opens the memory.oom_control file
buffer = str(efd.fileno())+" "+str(ofd.fileno()) #adds values of file descriptors of event notifications and memory.oom_control file to a buffer
cfd.writelines(buffer) #writes the event file descriptor efd and memory.oom_control file desciptor to the cgroups.event_control file desciptor by a buffer
cfd.close() #closes the cgroup.event_control file
print(ofd.read())
while True:
efd.read()
print("mem_cgroup oom event received")
Free Software Foundation, either version 3 of the License, or (at your option)
any later version.
linuxfd is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with linuxfd. If not, see <http://www.gnu.org/licenses/>.
Written in Python V3."""
import linuxfd, signal, select, time
# create special file objects
efd = linuxfd.eventfd(initval=0, nonBlocking=True)
sfd = linuxfd.signalfd(signalset={signal.SIGINT}, nonBlocking=True)
tfd = linuxfd.timerfd(rtc=True, nonBlocking=True)
# program timer and mask SIGINT
tfd.settime(3, 3)
signal.pthread_sigmask(signal.SIG_SETMASK, {signal.SIGINT})
# create epoll instance and register special files
epl = select.epoll()
epl.register(efd.fileno(), select.EPOLLIN)
epl.register(sfd.fileno(), select.EPOLLIN)
epl.register(tfd.fileno(), select.EPOLLIN)
# start main loop
isrunning = True
def get_eventfd(self, close_on_fork=True): fd = linuxfd.eventfd(initval=0, nonBlocking=True) if close_on_fork: self._close_on_fork_fds.add(fd) return fd
linuxfd is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with linuxfd. If not, see <http://www.gnu.org/licenses/>.
Written in Python V3."""
import linuxfd,signal,pprint,time,tempfile,os
#
# test eventfd
#
efd = linuxfd.eventfd(initval=0,nonBlocking=True)
print("\ntesting eventfd (fd={})".format(efd.fileno()))
for i in range(0,3):
print(" writing to sempahore")
efd.write()
try:
while True:
value = efd.read()
print(" read '{}' from semaphore".format(value))
except BlockingIOError:
print(" semaphore exhausted")
print("\ntesting eventfd (fd={}, mode: counting)".format(efd.fileno()))
efd = linuxfd.eventfd(initval=0,semaphore=True,nonBlocking=True)
for i in range(0,3):
print(" writing to sempahore")