PeterHarding at 06:07, 19 July 2009

2009-07-19T06:07:18Z

← Older revision		Revision as of 16:07, 19 July 2009
Line 374:		Line 374:

	[[Category:Python]]		[[Category:Python]]
			[[Category:Examples]]

PeterHarding at 02:21, 30 March 2009

2009-03-30T02:21:02Z

← Older revision		Revision as of 12:21, 30 March 2009
Line 2:		Line 2:
	#!/usr/bin/env python		#!/usr/bin/env python
	#		#
	# ~~Purpoe~~: Check ~~functionn~~ of fork ~~under~~ cygwin		# Purpose: Check function of fork() with cygwin
	#		#
	# $Id: fork2.py,v 1.1.1.1 2003/10/22 13:05:22 zyx Exp $		# $Id: fork2.py,v 1.1.1.1 2003/10/22 13:05:22 zyx Exp $
Line 11:		Line 11:
	More complex fork framework		More complex fork framework

	fork and in the child use setsid() and other calls to detach		fork() and in the child use setsid() and other calls to detach
	from the controllling terminal		from the controllling terminal
	"""		"""

PeterHarding at 02:59, 25 February 2008

2008-02-25T02:59:52Z

← Older revision		Revision as of 12:59, 25 February 2008
Line 372:		Line 372:
	"""		"""
	</pre>		</pre>

			[[Category:Python]]

PeterHarding: New page:

 #!/usr/bin/env python # #  Purpoe: Check functionn of fork under cygwin # #  $Id: fork2.py,v 1.1.1.1 2003/10/22 13:05:22 zyx Exp $ # #------------------------------------------------...

2008-02-15T04:44:26Z

New page: <pre> #!/usr/bin/env python # # Purpoe: Check functionn of fork under cygwin # # $Id: fork2.py,v 1.1.1.1 2003/10/22 13:05:22 zyx Exp $ # #------------------------------------------------...

New page

<pre>
#!/usr/bin/env python
#
# Purpoe: Check functionn of fork under cygwin
#
# $Id: fork2.py,v 1.1.1.1 2003/10/22 13:05:22 zyx Exp $
#
#---------------------------------------------------------------------

"""
More complex fork framework

fork and in the child use setsid() and other calls to detach
from the controllling terminal
"""

#---------------------------------------------------------------------

import getopt
import os
import sys
import signal
import time
import logging
import whrandom

#---------------------------------------------------------------------

__id__ = "@(#) fork2.py [1.0.0] 14/10/2003"
__version__ = "1.0.0"

TRUE = 1
FALSE = 0

LOGFILE = "fork2.log"
PIDFILE = "fork2.pid"

daemonFlg = 0
debugFlg = 0
silentFlg = 0
verboseFlg = 0
waitFlg = 0
inParent = 0

pause = 2
duration = 10
noSessions = 10

#=====================================================================

def now():
return time.ctime(time.time()) # current time on the server

#---------------------------------------------------------------------

def shutdown():
log.info("[fork2] Suttting down")

if inParent:
os.unlink(PIDFILE)

sys.exit(99)

#---------------------------------------------------------------------

def sigTerm(signum, frame):
"SIGTERM handler"

s = "[fork2] Caught SIGTERM!"
print s
log.info(s)

shutdown()

#---------------------------------------------------------------------

def readConfig():
pass

#---------------------------------------------------------------------

def checkRunning():
try:
pfp = open(PIDFILE, 'r')
except IOError, e:
pfp = 0

if pfp:
line = pfp.readline()
line = line.strip()

serverPid = int(line)

noProcess = 0

try:
os.kill(serverPid, 0)
except OSError, e:
if e.errno == 3:
noProcess = 1
else:
print "kill() failed with errno %d" % e.errno
sys.exit(0)

if noProcess:
print "[fork2] Stale server pid file!"
pfp.close()
os.unlink(PIDFILE)

return 0
else:
pfp.close()
return serverPid

return serverPid
else:
return 0

#---------------------------------------------------------------------

def writePidfile(pid):
try:
pfp = open(PIDFILE, 'w')
except IOError, e:
print "[fork2] Could not open %s" % PIDFILE
sys.exit(0)

print >>pfp, "%d" % pid

pfp.close()

return pid

#---------------------------------------------------------------------

def becomeDaemon():
pid = os.fork()

if pid == 0: # In child
print "[fork2] fork() -> 0 (%d)" % getpid()
time.sleep(1)
pass
elif pid == -1: # Error
print "[fork2] fork() failed!"
time.sleep(1)
sys.exit(0)
else: # In parent
print "[fork2] fork() ->", getpid()
time.sleep(1)
sys.exit(0)

time.sleep(2)

os.setsid()

pid = os.getpid()

return pid

#---------------------------------------------------------------------

def init():
global ctrlPid

ctrlPid = checkRunning()

if ctrlPid:
print "[fork2] Server already running! (pid = %d)" % ctrlPid
sys.exit(0)

if daemonFlg:
ctrlPid = becomeDaemon()
else:
ctrlPid = os.getpid()

writePidfile(ctrlPid)

global log

log = logging.getLogger('fork2')
hdlr = logging.FileHandler(LOGFILE)
fmtr = logging.Formatter('%(asctime)s %(levelname)s %(message)s')

hdlr.setFormatter(fmtr)
log.addHandler(hdlr)
log.setLevel(logging.INFO)

log.info("Server started processing")

global uname

readConfig()

if (not silentFlg):
print "[fork2] Server pid is %d" % ctrlPid

signal.signal(signal.SIGTERM, sigTerm)

#---------------------------------------------------------------------

def terminate():
serverPid = checkRunning()

if serverPid:
if (not silentFlg):
print "[fork2] Terminating server with pid, %d\n" % serverPid

os.kill(serverPid, signal.SIGTERM)

if (waitFlg):
while 1:
try:
kill(serverPid, 0)
except OSError, e:
if e.errno == 3:
break
else:
print "[server:terminate] kill() failed with errno %d" % e.errno
sys.exit(0)

time.sleep(1)

return 0

#=====================================================================

def doChild(no):
global inParent

inParent = 0

toGo = float(duration + 10)

#os.setsid()

pid = os.getpid()

signal.signal(signal.SIGTERM, sigTerm)

while toGo > 0.0:
t = whrandom.randint(1, 1000) * 0.001

toGo -= t
time.sleep(t)
s = "[fork2] In child %3d [%d] - %5.2f" % (no, pid, t)
log.info(s)
print s

#---------------------------------------------------------------------

def spawn():
global inParent

inParent = 1

pids = {}

for i in range(noSessions):
pid = os.fork()

if pid == 0: # In child
doChild(i)
elif pid == -1: # Error
print "[fork2] fork() failed!"
time.sleep(2)

sys.exit(0)
else: # In parent
pids[i] = pid

myPid = os.getpid()

print "[fork2] In parent [%d]: fork() -> %d" % (myPid, pid)
print "[fork2] In parent [%d]: waiting..." % myPid

time.sleep(duration)

print "[fork2] *** In parent [%d]: Applying SIGTERM" % myPid

for i in range(noSessions):
os.kill(pids[i], signal.SIGTERM)

while 1:
try:
(pid, status) = os.wait()
except OSError, e:
if e.errno == 10: # No children
break

print "[fork2] In parent - wait() --> (PID %d, Status %d, Signal %d)" % \
(pid, ((status & 0xff00)>>8), (status & 0xff))

i -= 1

return 0

#---------------------------------------------------------------------

def main():
global debugFlg
global verboseFlg
global waitFlg
global duration
global noSessions

try:
opts, args = getopt.getopt(sys.argv[1:], "dD:n:TvVw?")
except getopt.error, e:
print __doc__
return 1

wrk = os.getcwd()
base = os.path.basename(wrk)

for o, a in opts:
if o == '-d':
debugFlg = 1
elif o == '-D':
duration = int(a)
elif o == '-n':
noSessons = int(a)
elif o == '-T':
terminate()
return 0
elif o == '-v':
verboseFlg = 1
elif o == '-V':
print "[fork2] Version: %s" % __version__
return 1
elif o == '-w':
waitFlg = 1
elif o == '-?':
print __doc__
return 1

print "[fork2] Working directory is %s" % os.getcwd()

if args:
for arg in args:
print arg

init()

spawn()

#---------------------------------------------------------------------

if __name__ == '__main__' or __name__ == sys.argv[0]:
try:
sys.exit(main())
except KeyboardInterrupt, e:
s = "[fork2] Interrupted!"
print s
log.info(s)
shutdown()

#---------------------------------------------------------------------

"""
Revision History:

Date Who Description
-------- --- --------------------------------------------------
20031018 plh Initial implementation

Problems to fix:

To Do:

Issues:

"""
</pre>

Fork.py - Revision history

PeterHarding at 06:07, 19 July 2009

PeterHarding at 02:21, 30 March 2009

PeterHarding at 02:59, 25 February 2008

PeterHarding: New page:
#!/usr/bin/env python # # Purpoe: Check functionn of fork under cygwin # # $Id: fork2.py,v 1.1.1.1 2003/10/22 13:05:22 zyx Exp $ # #------------------------------------------------...