我编写了一个python守护程序脚本并注册了一些信号处理程序，但是当我使用kill -1 pid时，我发现信号处理程序不起作用。
任何人都知道为什么？
这是脚本：
test.py：
#!/usr/bin/env python
import sys, time
from daemon import Daemon
import threading
import signal
class MyDaemon(Daemon):
def run(self):
time.sleep(1)
threading.Thread(target=mythread).start()
threading.Thread(target=mythread2).start()
def mythread():
while 1:
raise Exception,"shit"
def mythread2():
while 1:
time.sleep(1)
print "22222222222"
if __name__ == "__main__":
daemon = MyDaemon('/tmp/daemon-example.pid')
if len(sys.argv) == 2:
if 'start' == sys.argv[1]:
daemon.start()
elif 'stop' == sys.argv[1]:
daemon.stop()
elif 'restart' == sys.argv[1]:
daemon.restart()
else:
print "Unknown command"
sys.exit(2)
sys.exit(0)
else:
print "usage: %s start|stop|restart" % sys.argv[0]
sys.exit(2)
daemon.py：
#!/usr/bin/env python
import sys, os, time, atexit
from signal import SIGTERM
import signal
import logging
import logging.handlers
LOG_FILENAME = "/tmp/myservice.log"
LOG_LEVEL = logging.INFO # Could be e.g. "DEBUG" or "WARNING"
# Configure logging to log to a file, making a new file at midnight and keeping the last 3 day's data
# Give the logger a unique name (good practice)
logger = logging.getLogger(__name__)
# Set the log level to LOG_LEVEL
logger.setLevel(LOG_LEVEL)
# Make a handler that writes to a file, making a new file at midnight and keeping 3 backups
handler = logging.handlers.TimedRotatingFileHandler(LOG_FILENAME, when="midnight", backupCount=3)
# Format each log message like this
formatter = logging.Formatter('%(asctime)s %(levelname)-8s %(message)s')
# Attach the formatter to the handler
handler.setFormatter(formatter)
# Attach the handler to the logger
logger.addHandler(handler)
# Make a class we can use to capture stdout and sterr in the log
class MyLogger(object):
def __init__(self, logger, level):
"""Needs a logger and a logger level."""
self.logger = logger
self.level = level
def write(self, message):
# Only log if there is a message (not just a new line)
if message.rstrip() != "":
self.logger.log(self.level, message.rstrip())
# Replace stdout with logging to file at INFO level
sys.stdout = MyLogger(logger, logging.INFO)
# Replace stderr with logging to file at ERROR level
sys.stderr = MyLogger(logger, logging.ERROR)
def signal_handler(signum,stack):
print "signal:%s" % signum
signal.signal(signal.SIGHUP,signal_handler)
signal.signal(signal.SIGINT,signal_handler)
signal.signal(signal.SIGTERM,signal_handler)
class Daemon:
"""
A generic daemon class.
Usage: subclass the Daemon class and override the run() method
"""
def __init__(self, pidfile, stdin='/dev/null', stdout='/tmp/out.txt', stderr='/tmp/err.txt'):
self.stdin = stdin
self.stdout = stdout
self.stderr = stderr
self.pidfile = pidfile
def daemonize(self):
"""
do the UNIX double-fork magic, see Stevens' "Advanced
Programming in the UNIX Environment" for details (ISBN 0201563177)
http://www.erlenstar.demon.co.uk/unix/faq_2.html#SEC16
"""
try:
pid = os.fork()
if pid > 0:
# exit first parent
sys.exit(0)
except OSError, e:
sys.stderr.write("fork #1 failed: %d (%s)\n" % (e.errno, e.strerror))
sys.exit(1)
# decouple from parent environment
os.chdir("/")
os.setsid()
os.umask(0)
# do second fork
try:
pid = os.fork()
if pid > 0:
# exit from second parent
sys.exit(0)
except OSError, e:
sys.stderr.write("fork #2 failed: %d (%s)\n" % (e.errno, e.strerror))
sys.exit(1)
# redirect standard file descriptors
# sys.stdout.flush()
# sys.stderr.flush()
# si = file(self.stdin, 'r')
# so = file(self.stdout, 'a+', 0)
# se = file(self.stderr, 'a+', 0)
# os.dup2(si.fileno(), sys.stdin.fileno())
# os.dup2(so.fileno(), sys.stdout.fileno())
# os.dup2(se.fileno(), sys.stderr.fileno())
# write pidfile
atexit.register(self.delpid)
pid = str(os.getpid())
file(self.pidfile,'w+').write("%s\n" % pid)
def delpid(self):
os.remove(self.pidfile)
def start(self):
"""
Start the daemon
"""
# Check for a pidfile to see if the daemon already runs
try:
pf = file(self.pidfile,'r')
pid = int(pf.read().strip())
pf.close()
except IOError:
pid = None
if pid:
message = "pidfile %s already exist. Daemon already running?\n"
sys.stderr.write(message % self.pidfile)
sys.exit(1)
# Start the daemon
self.daemonize()
self.run()
def stop(self):
"""
Stop the daemon
"""
# Get the pid from the pidfile
try:
pf = file(self.pidfile,'r')
pid = int(pf.read().strip())
pf.close()
except IOError:
pid = None
if not pid:
message = "pidfile %s does not exist. Daemon not running?\n"
sys.stderr.write(message % self.pidfile)
return # not an error in a restart
# Try killing the daemon process
try:
while 1:
os.kill(pid, SIGTERM)
time.sleep(0.1)
except OSError, err:
err = str(err)
if err.find("No such process") > 0:
if os.path.exists(self.pidfile):
os.remove(self.pidfile)
else:
print str(err)
sys.exit(1)
def restart(self):
"""
Restart the daemon
"""
self.stop()
self.start()
def run(self):
"""
You should override this method when you subclass Daemon. It will be called after the process has been
daemonized by start() or restart().
"""
如您所见，当我对test.py使用kill命令时，日志文件中没有任何打印。
答案 0 :(得分：0)
信号仅发送到单个线程。如果由于异常而导致您的第一个帖子mythread()被释放，则不会发生任何事情。
尝试颠倒调度线程的顺序，以便查看。