class StandardIO(object):
implements(interfaces.ITransport, interfaces.IProducer,
interfaces.IConsumer, interfaces.IHalfCloseableDescriptor)
_reader = None
_writer = None
disconnected = False
disconnecting = False
def __init__(self, proto, stdin=0, stdout=1):
from twisted.internet import reactor
self.protocol = proto
self._writer = process.ProcessWriter(reactor, self, 'write', stdout)
try:
self._writer.startReading()
except IOError, e:
if e.errno == errno.EPERM:
# epoll will reject certain file descriptors by raising
# EPERM. Most commonly, this means stdout was redirected to
# a regular file.
raise RuntimeError(
"This reactor does not support this type of file "
"descriptor (fd %d, mode %d) (for example, epollreactor "
"does not support normal files. See #4429)." %
(stdout, os.fstat(stdout).st_mode))
raise
self._reader = process.ProcessReader(reactor, self, 'read', stdin)
self._reader.startReading()
self.protocol.makeConnection(self)
def __init__(self, proto, stdin=0, stdout=1, reactor=None):
if reactor is None:
from twisted.internet import reactor
self.protocol = proto
self._writer = process.ProcessWriter(reactor, self, "write", stdout)
self._reader = process.ProcessReader(reactor, self, "read", stdin)
self._reader.startReading()
self.protocol.makeConnection(self)
def __init__(self, proto, stdin=0, stdout=1):
from twisted.internet import reactor
self.protocol = proto
self._reader = process.ProcessReader(reactor, self, 'read', stdin)
self._reader.startReading()
self._writer = process.ProcessWriter(reactor, self, 'write', stdout)
self._writer.startReading()
self.protocol.makeConnection(self)
def connectionMade(self):
debug("outgoing connection made")
self.reader = process.ProcessReader(self.reactor, self, "in", 0)
def __init__(self,
reactor,
command,
args,
environment,
path,
proto,
uid=None,
gid=None,
childFDs=None,
sessionLeader=False,
timeout=None):
"""Spawn an operating-system process.
This is where the hard work of disconnecting all currently open
files / forking / executing the new process happens. (This is
executed automatically when a Process is instantiated.)
This will also run the subprocess as a given user ID and group ID, if
specified. (Implementation Note: this doesn't support all the arcane
nuances of setXXuid on UNIX: it will assume that either your effective
or real UID is 0.)
"""
if not proto:
assert 'r' not in childFDs.values()
assert 'w' not in childFDs.values()
if not signal.getsignal(signal.SIGCHLD):
log.msg("spawnProcess called, but the SIGCHLD handler is not "
"installed. This probably means you have not yet "
"called reactor.run, or called "
"reactor.run(installSignalHandler=0). You will probably "
"never see this process finish, and it may become a "
"zombie process.")
# if you see this message during a unit test, look in
# test-standard.xhtml or twisted.test.test_process.SignalMixin
# for a workaround
self.lostProcess = False
settingUID = (uid is not None) or (gid is not None)
if settingUID:
curegid = os.getegid()
currgid = os.getgid()
cureuid = os.geteuid()
curruid = os.getuid()
if uid is None:
uid = cureuid
if gid is None:
gid = curegid
# prepare to change UID in subprocess
os.setuid(0)
os.setgid(0)
self.pipes = {}
# keys are childFDs, we can sense them closing
# values are ProcessReader/ProcessWriters
helpers = {}
# keys are childFDs
# values are parentFDs
if childFDs is None:
childFDs = {
0: "w", # we write to the child's stdin
1: "r", # we read from their stdout
2: "r", # and we read from their stderr
}
debug = self.debug
if debug: print "childFDs", childFDs
# fdmap.keys() are filenos of pipes that are used by the child.
fdmap = {} # maps childFD to parentFD
for childFD, target in childFDs.items():
if debug: print "[%d]" % childFD, target
if target == "r":
# we need a pipe that the parent can read from
readFD, writeFD = os.pipe()
if debug: print "readFD=%d, writeFD%d" % (readFD, writeFD)
fdmap[childFD] = writeFD # child writes to this
helpers[childFD] = readFD # parent reads from this
elif target == "w":
# we need a pipe that the parent can write to
readFD, writeFD = os.pipe()
if debug: print "readFD=%d, writeFD=%d" % (readFD, writeFD)
fdmap[childFD] = readFD # child reads from this
helpers[childFD] = writeFD # parent writes to this
else:
assert type(target) == int, '%r should be an int' % (target, )
fdmap[childFD] = target # parent ignores this
if debug: print "fdmap", fdmap
if debug: print "helpers", helpers
# the child only cares about fdmap.values()
self.pid = os.fork()
if self.pid == 0: # pid is 0 in the child process
# do not put *ANY* code outside the try block. The child process
# must either exec or _exit. If it gets outside this block (due
# to an exception that is not handled here, but which might be
# handled higher up), there will be two copies of the parent
# running in parallel, doing all kinds of damage.
# After each change to this code, review it to make sure there
# are no exit paths.
try:
# stop debugging, if I am! I don't care anymore!
sys.settrace(None)
# close all parent-side pipes
self._setupChild(fdmap)
# Make a session/process group leader if requested
if sessionLeader: self._setupSession()
self._execChild(path, settingUID, uid, gid, command, args,
environment)
except:
# If there are errors, bail and try to write something
# descriptive to stderr.
# XXX: The parent's stderr isn't necessarily fd 2 anymore, or
# even still available
# XXXX: however even libc assumes write(2,err) is a useful
# thing to attempt
try:
stderr = os.fdopen(2, 'w')
stderr.write(
"Upon execvpe %s %s in environment %s\n:" %
(command, str(args), "id %s" % id(environment)))
traceback.print_exc(file=stderr)
stderr.flush()
for fd in range(3):
os.close(fd)
except:
pass # make *sure* the child terminates
# Did you read the comment about not adding code here?
os._exit(1)
# we are the parent
if settingUID:
os.setregid(currgid, curegid)
os.setreuid(curruid, cureuid)
self.status = -1 # this records the exit status of the child
if timeout:
self.timeoutCall = reactor.callLater(timeout, self._processTimeout)
self.proto = proto
# arrange for the parent-side pipes to be read and written
for childFD, parentFD in helpers.items():
os.close(fdmap[childFD])
if childFDs[childFD] == "r":
reader = process.ProcessReader(reactor, self, childFD,
parentFD)
self.pipes[childFD] = reader
if childFDs[childFD] == "w":
writer = process.ProcessWriter(reactor,
self,
childFD,
parentFD,
forceReadHack=True)
self.pipes[childFD] = writer
try:
# the 'transport' is used for some compatibility methods
if self.proto is not None:
self.proto.makeConnection(self)
except:
log.err()
process.registerReapProcessHandler(self.pid, self)
