gecko/testing/mozharness/mozprocess/processhandler.py

922 lines
40 KiB
Python

# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this file,
# You can obtain one at http://mozilla.org/MPL/2.0/.
import os
import select
import signal
import subprocess
import sys
import threading
import time
import traceback
from Queue import Queue
from datetime import datetime, timedelta
__all__ = ['ProcessHandlerMixin', 'ProcessHandler']
# Set the MOZPROCESS_DEBUG environment variable to 1 to see some debugging output
MOZPROCESS_DEBUG = os.getenv("MOZPROCESS_DEBUG")
# We dont use mozinfo because it is expensive to import, see bug 933558.
isWin = os.name == "nt"
isPosix = os.name == "posix" # includes MacOS X
if isWin:
import ctypes, ctypes.wintypes, msvcrt
from ctypes import sizeof, addressof, c_ulong, byref, POINTER, WinError, c_longlong
import winprocess
from qijo import JobObjectAssociateCompletionPortInformation,\
JOBOBJECT_ASSOCIATE_COMPLETION_PORT, JobObjectExtendedLimitInformation,\
JOBOBJECT_BASIC_LIMIT_INFORMATION, JOBOBJECT_EXTENDED_LIMIT_INFORMATION, IO_COUNTERS
class ProcessHandlerMixin(object):
"""
A class for launching and manipulating local processes.
:param cmd: command to run. May be a string or a list. If specified as a list, the first element will be interpreted as the command, and all additional elements will be interpreted as arguments to that command.
:param args: list of arguments to pass to the command (defaults to None). Must not be set when `cmd` is specified as a list.
:param cwd: working directory for command (defaults to None).
:param env: is the environment to use for the process (defaults to os.environ).
:param ignore_children: causes system to ignore child processes when True, defaults to False (which tracks child processes).
:param kill_on_timeout: when True, the process will be killed when a timeout is reached. When False, the caller is responsible for killing the process. Failure to do so could cause a call to wait() to hang indefinitely. (Defaults to True.)
:param processOutputLine: function to be called for each line of output produced by the process (defaults to None).
:param onTimeout: function to be called when the process times out.
:param onFinish: function to be called when the process terminates normally without timing out.
:param kwargs: additional keyword args to pass directly into Popen.
NOTE: Child processes will be tracked by default. If for any reason
we are unable to track child processes and ignore_children is set to False,
then we will fall back to only tracking the root process. The fallback
will be logged.
"""
class Process(subprocess.Popen):
"""
Represents our view of a subprocess.
It adds a kill() method which allows it to be stopped explicitly.
"""
MAX_IOCOMPLETION_PORT_NOTIFICATION_DELAY = 180
MAX_PROCESS_KILL_DELAY = 30
def __init__(self,
args,
bufsize=0,
executable=None,
stdin=None,
stdout=None,
stderr=None,
preexec_fn=None,
close_fds=False,
shell=False,
cwd=None,
env=None,
universal_newlines=False,
startupinfo=None,
creationflags=0,
ignore_children=False):
# Parameter for whether or not we should attempt to track child processes
self._ignore_children = ignore_children
if not self._ignore_children and not isWin:
# Set the process group id for linux systems
# Sets process group id to the pid of the parent process
# NOTE: This prevents you from using preexec_fn and managing
# child processes, TODO: Ideally, find a way around this
def setpgidfn():
os.setpgid(0, 0)
preexec_fn = setpgidfn
try:
subprocess.Popen.__init__(self, args, bufsize, executable,
stdin, stdout, stderr,
preexec_fn, close_fds,
shell, cwd, env,
universal_newlines, startupinfo, creationflags)
except OSError, e:
print >> sys.stderr, args
raise
def __del__(self, _maxint=sys.maxint):
if isWin:
if self._handle:
if hasattr(self, '_internal_poll'):
self._internal_poll(_deadstate=_maxint)
else:
self.poll(_deadstate=sys.maxint)
if self._handle or self._job or self._io_port:
self._cleanup()
else:
subprocess.Popen.__del__(self)
def kill(self, sig=None):
self.returncode = 0
if isWin:
if not self._ignore_children and self._handle and self._job:
winprocess.TerminateJobObject(self._job, winprocess.ERROR_CONTROL_C_EXIT)
self.returncode = winprocess.GetExitCodeProcess(self._handle)
elif self._handle:
err = None
try:
winprocess.TerminateProcess(self._handle, winprocess.ERROR_CONTROL_C_EXIT)
except:
err = "Could not terminate process"
self.returncode = winprocess.GetExitCodeProcess(self._handle)
self._cleanup()
if err is not None:
raise OSError(err)
else:
sig = sig or signal.SIGKILL
if not self._ignore_children:
try:
os.killpg(self.pid, sig)
except BaseException, e:
if getattr(e, "errno", None) != 3:
# Error 3 is "no such process", which is ok
print >> sys.stdout, "Could not kill process, could not find pid: %s, assuming it's already dead" % self.pid
else:
os.kill(self.pid, sig)
self.returncode = -sig
self._cleanup()
return self.returncode
def wait(self):
""" Popen.wait
Called to wait for a running process to shut down and return
its exit code
Returns the main process's exit code
"""
# This call will be different for each OS
self.returncode = self._wait()
self._cleanup()
return self.returncode
""" Private Members of Process class """
if isWin:
# Redefine the execute child so that we can track process groups
def _execute_child(self, *args_tuple):
# workaround for bug 950894
if sys.hexversion < 0x02070600: # prior to 2.7.6
(args, executable, preexec_fn, close_fds,
cwd, env, universal_newlines, startupinfo,
creationflags, shell,
p2cread, p2cwrite,
c2pread, c2pwrite,
errread, errwrite) = args_tuple
to_close = set()
else: # 2.7.6 and later
(args, executable, preexec_fn, close_fds,
cwd, env, universal_newlines, startupinfo,
creationflags, shell, to_close,
p2cread, p2cwrite,
c2pread, c2pwrite,
errread, errwrite) = args_tuple
if not isinstance(args, basestring):
args = subprocess.list2cmdline(args)
# Always or in the create new process group
creationflags |= winprocess.CREATE_NEW_PROCESS_GROUP
if startupinfo is None:
startupinfo = winprocess.STARTUPINFO()
if None not in (p2cread, c2pwrite, errwrite):
startupinfo.dwFlags |= winprocess.STARTF_USESTDHANDLES
startupinfo.hStdInput = int(p2cread)
startupinfo.hStdOutput = int(c2pwrite)
startupinfo.hStdError = int(errwrite)
if shell:
startupinfo.dwFlags |= winprocess.STARTF_USESHOWWINDOW
startupinfo.wShowWindow = winprocess.SW_HIDE
comspec = os.environ.get("COMSPEC", "cmd.exe")
args = comspec + " /c " + args
# determine if we can create create a job
canCreateJob = winprocess.CanCreateJobObject()
# Ensure we write a warning message if we are falling back
if not canCreateJob and not self._ignore_children:
# We can't create job objects AND the user wanted us to
# Warn the user about this.
print >> sys.stderr, "ProcessManager UNABLE to use job objects to manage child processes"
# set process creation flags
creationflags |= winprocess.CREATE_SUSPENDED
creationflags |= winprocess.CREATE_UNICODE_ENVIRONMENT
if canCreateJob:
creationflags |= winprocess.CREATE_BREAKAWAY_FROM_JOB
else:
# Since we've warned, we just log info here to inform you
# of the consequence of setting ignore_children = True
print "ProcessManager NOT managing child processes"
# create the process
hp, ht, pid, tid = winprocess.CreateProcess(
executable, args,
None, None, # No special security
1, # Must inherit handles!
creationflags,
winprocess.EnvironmentBlock(env),
cwd, startupinfo)
self._child_created = True
self._handle = hp
self._thread = ht
self.pid = pid
self.tid = tid
if not self._ignore_children and canCreateJob:
try:
# We create a new job for this process, so that we can kill
# the process and any sub-processes
# Create the IO Completion Port
self._io_port = winprocess.CreateIoCompletionPort()
self._job = winprocess.CreateJobObject()
# Now associate the io comp port and the job object
joacp = JOBOBJECT_ASSOCIATE_COMPLETION_PORT(winprocess.COMPKEY_JOBOBJECT,
self._io_port)
winprocess.SetInformationJobObject(self._job,
JobObjectAssociateCompletionPortInformation,
addressof(joacp),
sizeof(joacp)
)
# Allow subprocesses to break away from us - necessary for
# flash with protected mode
jbli = JOBOBJECT_BASIC_LIMIT_INFORMATION(
c_longlong(0), # per process time limit (ignored)
c_longlong(0), # per job user time limit (ignored)
winprocess.JOB_OBJECT_LIMIT_BREAKAWAY_OK,
0, # min working set (ignored)
0, # max working set (ignored)
0, # active process limit (ignored)
None, # affinity (ignored)
0, # Priority class (ignored)
0, # Scheduling class (ignored)
)
iocntr = IO_COUNTERS()
jeli = JOBOBJECT_EXTENDED_LIMIT_INFORMATION(
jbli, # basic limit info struct
iocntr, # io_counters (ignored)
0, # process mem limit (ignored)
0, # job mem limit (ignored)
0, # peak process limit (ignored)
0) # peak job limit (ignored)
winprocess.SetInformationJobObject(self._job,
JobObjectExtendedLimitInformation,
addressof(jeli),
sizeof(jeli)
)
# Assign the job object to the process
winprocess.AssignProcessToJobObject(self._job, int(hp))
# It's overkill, but we use Queue to signal between threads
# because it handles errors more gracefully than event or condition.
self._process_events = Queue()
# Spin up our thread for managing the IO Completion Port
self._procmgrthread = threading.Thread(target = self._procmgr)
except:
print >> sys.stderr, """Exception trying to use job objects;
falling back to not using job objects for managing child processes"""
tb = traceback.format_exc()
print >> sys.stderr, tb
# Ensure no dangling handles left behind
self._cleanup_job_io_port()
else:
self._job = None
winprocess.ResumeThread(int(ht))
if getattr(self, '_procmgrthread', None):
self._procmgrthread.start()
ht.Close()
for i in (p2cread, c2pwrite, errwrite):
if i is not None:
i.Close()
# Windows Process Manager - watches the IO Completion Port and
# keeps track of child processes
def _procmgr(self):
if not (self._io_port) or not (self._job):
return
try:
self._poll_iocompletion_port()
except KeyboardInterrupt:
raise KeyboardInterrupt
def _poll_iocompletion_port(self):
# Watch the IO Completion port for status
self._spawned_procs = {}
countdowntokill = 0
if MOZPROCESS_DEBUG:
print "DBG::MOZPROC Self.pid value is: %s" % self.pid
while True:
msgid = c_ulong(0)
compkey = c_ulong(0)
pid = c_ulong(0)
portstatus = winprocess.GetQueuedCompletionStatus(self._io_port,
byref(msgid),
byref(compkey),
byref(pid),
5000)
# If the countdowntokill has been activated, we need to check
# if we should start killing the children or not.
if countdowntokill != 0:
diff = datetime.now() - countdowntokill
# Arbitrarily wait 3 minutes for windows to get its act together
# Windows sometimes takes a small nap between notifying the
# IO Completion port and actually killing the children, and we
# don't want to mistake that situation for the situation of an unexpected
# parent abort (which is what we're looking for here).
if diff.seconds > self.MAX_IOCOMPLETION_PORT_NOTIFICATION_DELAY:
print >> sys.stderr, "Parent process %s exited with children alive:" % self.pid
print >> sys.stderr, "PIDS: %s" % ', '.join([str(i) for i in self._spawned_procs])
print >> sys.stderr, "Attempting to kill them..."
self.kill()
self._process_events.put({self.pid: 'FINISHED'})
if not portstatus:
# Check to see what happened
errcode = winprocess.GetLastError()
if errcode == winprocess.ERROR_ABANDONED_WAIT_0:
# Then something has killed the port, break the loop
print >> sys.stderr, "IO Completion Port unexpectedly closed"
break
elif errcode == winprocess.WAIT_TIMEOUT:
# Timeouts are expected, just keep on polling
continue
else:
print >> sys.stderr, "Error Code %s trying to query IO Completion Port, exiting" % errcode
raise WinError(errcode)
break
if compkey.value == winprocess.COMPKEY_TERMINATE.value:
if MOZPROCESS_DEBUG:
print "DBG::MOZPROC compkeyterminate detected"
# Then we're done
break
# Check the status of the IO Port and do things based on it
if compkey.value == winprocess.COMPKEY_JOBOBJECT.value:
if msgid.value == winprocess.JOB_OBJECT_MSG_ACTIVE_PROCESS_ZERO:
# No processes left, time to shut down
# Signal anyone waiting on us that it is safe to shut down
if MOZPROCESS_DEBUG:
print "DBG::MOZPROC job object msg active processes zero"
self._process_events.put({self.pid: 'FINISHED'})
break
elif msgid.value == winprocess.JOB_OBJECT_MSG_NEW_PROCESS:
# New Process started
# Add the child proc to our list in case our parent flakes out on us
# without killing everything.
if pid.value != self.pid:
self._spawned_procs[pid.value] = 1
if MOZPROCESS_DEBUG:
print "DBG::MOZPROC new process detected with pid value: %s" % pid.value
elif msgid.value == winprocess.JOB_OBJECT_MSG_EXIT_PROCESS:
if MOZPROCESS_DEBUG:
print "DBG::MOZPROC process id %s exited normally" % pid.value
# One process exited normally
if pid.value == self.pid and len(self._spawned_procs) > 0:
# Parent process dying, start countdown timer
countdowntokill = datetime.now()
elif pid.value in self._spawned_procs:
# Child Process died remove from list
del(self._spawned_procs[pid.value])
elif msgid.value == winprocess.JOB_OBJECT_MSG_ABNORMAL_EXIT_PROCESS:
# One process existed abnormally
if MOZPROCESS_DEBUG:
print "DBG::MOZPROC process id %s existed abnormally" % pid.value
if pid.value == self.pid and len(self._spawned_procs) > 0:
# Parent process dying, start countdown timer
countdowntokill = datetime.now()
elif pid.value in self._spawned_procs:
# Child Process died remove from list
del self._spawned_procs[pid.value]
else:
# We don't care about anything else
if MOZPROCESS_DEBUG:
print "DBG::MOZPROC We got a message %s" % msgid.value
pass
def _wait(self):
# First, check to see if the process is still running
if self._handle:
self.returncode = winprocess.GetExitCodeProcess(self._handle)
else:
# Dude, the process is like totally dead!
return self.returncode
# Python 2.5 uses isAlive versus is_alive use the proper one
threadalive = False
if hasattr(self, "_procmgrthread"):
if hasattr(self._procmgrthread, 'is_alive'):
threadalive = self._procmgrthread.is_alive()
else:
threadalive = self._procmgrthread.isAlive()
if self._job and threadalive:
# Then we are managing with IO Completion Ports
# wait on a signal so we know when we have seen the last
# process come through.
# We use queues to synchronize between the thread and this
# function because events just didn't have robust enough error
# handling on pre-2.7 versions
err = None
try:
# timeout is the max amount of time the procmgr thread will wait for
# child processes to shutdown before killing them with extreme prejudice.
item = self._process_events.get(timeout=self.MAX_IOCOMPLETION_PORT_NOTIFICATION_DELAY +
self.MAX_PROCESS_KILL_DELAY)
if item[self.pid] == 'FINISHED':
self._process_events.task_done()
except:
err = "IO Completion Port failed to signal process shutdown"
# Either way, let's try to get this code
if self._handle:
self.returncode = winprocess.GetExitCodeProcess(self._handle)
self._cleanup()
if err is not None:
raise OSError(err)
else:
# Not managing with job objects, so all we can reasonably do
# is call waitforsingleobject and hope for the best
if MOZPROCESS_DEBUG and not self._ignore_children:
print "DBG::MOZPROC NOT USING JOB OBJECTS!!!"
# First, make sure we have not already ended
if self.returncode != winprocess.STILL_ACTIVE:
self._cleanup()
return self.returncode
rc = None
if self._handle:
rc = winprocess.WaitForSingleObject(self._handle, -1)
if rc == winprocess.WAIT_TIMEOUT:
# The process isn't dead, so kill it
print "Timed out waiting for process to close, attempting TerminateProcess"
self.kill()
elif rc == winprocess.WAIT_OBJECT_0:
# We caught WAIT_OBJECT_0, which indicates all is well
print "Single process terminated successfully"
self.returncode = winprocess.GetExitCodeProcess(self._handle)
else:
# An error occured we should probably throw
rc = winprocess.GetLastError()
if rc:
raise WinError(rc)
self._cleanup()
return self.returncode
def _cleanup_job_io_port(self):
""" Do the job and IO port cleanup separately because there are
cases where we want to clean these without killing _handle
(i.e. if we fail to create the job object in the first place)
"""
if getattr(self, '_job') and self._job != winprocess.INVALID_HANDLE_VALUE:
self._job.Close()
self._job = None
else:
# If windows already freed our handle just set it to none
# (saw this intermittently while testing)
self._job = None
if getattr(self, '_io_port', None) and self._io_port != winprocess.INVALID_HANDLE_VALUE:
self._io_port.Close()
self._io_port = None
else:
self._io_port = None
if getattr(self, '_procmgrthread', None):
self._procmgrthread = None
def _cleanup(self):
self._cleanup_job_io_port()
if self._thread and self._thread != winprocess.INVALID_HANDLE_VALUE:
self._thread.Close()
self._thread = None
else:
self._thread = None
if self._handle and self._handle != winprocess.INVALID_HANDLE_VALUE:
self._handle.Close()
self._handle = None
else:
self._handle = None
elif isPosix:
def _wait(self):
""" Haven't found any reason to differentiate between these platforms
so they all use the same wait callback. If it is necessary to
craft different styles of wait, then a new _wait method
could be easily implemented.
"""
if not self._ignore_children:
try:
# os.waitpid return value:
# > [...] a tuple containing its pid and exit status
# > indication: a 16-bit number, whose low byte is the
# > signal number that killed the process, and whose
# > high byte is the exit status (if the signal number
# > is zero)
# - http://docs.python.org/2/library/os.html#os.wait
status = os.waitpid(self.pid, 0)[1]
# For consistency, format status the same as subprocess'
# returncode attribute
if status > 255:
return status >> 8
return -status
except OSError, e:
if getattr(e, "errno", None) != 10:
# Error 10 is "no child process", which could indicate normal
# close
print >> sys.stderr, "Encountered error waiting for pid to close: %s" % e
raise
return 0
else:
# For non-group wait, call base class
subprocess.Popen.wait(self)
return self.returncode
def _cleanup(self):
pass
else:
# An unrecognized platform, we will call the base class for everything
print >> sys.stderr, "Unrecognized platform, process groups may not be managed properly"
def _wait(self):
self.returncode = subprocess.Popen.wait(self)
return self.returncode
def _cleanup(self):
pass
def __init__(self,
cmd,
args=None,
cwd=None,
env=None,
ignore_children = False,
kill_on_timeout = True,
processOutputLine=(),
onTimeout=(),
onFinish=(),
**kwargs):
self.cmd = cmd
self.args = args
self.cwd = cwd
self.didTimeout = False
self._ignore_children = ignore_children
self._kill_on_timeout = kill_on_timeout
self.keywordargs = kwargs
self.outThread = None
self.read_buffer = ''
if env is None:
env = os.environ.copy()
self.env = env
# handlers
self.processOutputLineHandlers = list(processOutputLine)
self.onTimeoutHandlers = list(onTimeout)
self.onFinishHandlers = list(onFinish)
# It is common for people to pass in the entire array with the cmd and
# the args together since this is how Popen uses it. Allow for that.
if isinstance(self.cmd, list):
if self.args != None:
raise TypeError("cmd and args must not both be lists")
(self.cmd, self.args) = (self.cmd[0], self.cmd[1:])
elif self.args is None:
self.args = []
@property
def timedOut(self):
"""True if the process has timed out."""
return self.didTimeout
@property
def commandline(self):
"""the string value of the command line (command + args)"""
return subprocess.list2cmdline([self.cmd] + self.args)
def run(self, timeout=None, outputTimeout=None):
"""
Starts the process.
If timeout is not None, the process will be allowed to continue for
that number of seconds before being killed. If the process is killed
due to a timeout, the onTimeout handler will be called.
If outputTimeout is not None, the process will be allowed to continue
for that number of seconds without producing any output before
being killed.
"""
self.didTimeout = False
self.startTime = datetime.now()
# default arguments
args = dict(stdout=subprocess.PIPE,
stderr=subprocess.STDOUT,
cwd=self.cwd,
env=self.env,
ignore_children=self._ignore_children)
# build process arguments
args.update(self.keywordargs)
# launch the process
self.proc = self.Process([self.cmd] + self.args, **args)
self.processOutput(timeout=timeout, outputTimeout=outputTimeout)
def kill(self, sig=None):
"""
Kills the managed process.
If you created the process with 'ignore_children=False' (the
default) then it will also also kill all child processes spawned by
it. If you specified 'ignore_children=True' when creating the
process, only the root process will be killed.
Note that this does not manage any state, save any output etc,
it immediately kills the process.
:param sig: Signal used to kill the process, defaults to SIGKILL
(has no effect on Windows)
"""
try:
return self.proc.kill(sig=sig)
except AttributeError:
# Try to print a relevant error message.
if not self.proc:
print >> sys.stderr, "Unable to kill Process because call to ProcessHandler constructor failed."
else:
raise
def readWithTimeout(self, f, timeout):
"""
Try to read a line of output from the file object *f*.
*f* must be a pipe, like the *stdout* member of a subprocess.Popen
object created with stdout=PIPE. If no output
is received within *timeout* seconds, return a blank line.
Returns a tuple (line, did_timeout), where *did_timeout* is True
if the read timed out, and False otherwise.
"""
# Calls a private member because this is a different function based on
# the OS
return self._readWithTimeout(f, timeout)
def processOutputLine(self, line):
"""Called for each line of output that a process sends to stdout/stderr."""
for handler in self.processOutputLineHandlers:
handler(line)
def onTimeout(self):
"""Called when a process times out."""
for handler in self.onTimeoutHandlers:
handler()
def onFinish(self):
"""Called when a process finishes without a timeout."""
for handler in self.onFinishHandlers:
handler()
def processOutput(self, timeout=None, outputTimeout=None):
"""
Handle process output until the process terminates or times out.
If timeout is not None, the process will be allowed to continue for
that number of seconds before being killed.
If outputTimeout is not None, the process will be allowed to continue
for that number of seconds without producing any output before
being killed.
"""
def _processOutput():
self.didTimeout = False
logsource = self.proc.stdout
lineReadTimeout = None
if timeout:
lineReadTimeout = timeout - (datetime.now() - self.startTime).seconds
elif outputTimeout:
lineReadTimeout = outputTimeout
(lines, self.didTimeout) = self.readWithTimeout(logsource, lineReadTimeout)
while lines != "":
for line in lines.splitlines():
self.processOutputLine(line.rstrip())
if self.didTimeout:
break
if timeout:
lineReadTimeout = timeout - (datetime.now() - self.startTime).seconds
(lines, self.didTimeout) = self.readWithTimeout(logsource, lineReadTimeout)
if self.didTimeout:
if self._kill_on_timeout:
self.proc.kill()
self.onTimeout()
else:
self.onFinish()
if not hasattr(self, 'proc'):
self.run()
if not self.outThread:
self.outThread = threading.Thread(target=_processOutput)
self.outThread.daemon = True
self.outThread.start()
def wait(self, timeout=None):
"""
Waits until all output has been read and the process is
terminated.
If timeout is not None, will return after timeout seconds.
This timeout only causes the wait function to return and
does not kill the process.
Returns the process' exit code. A None value indicates the
process hasn't terminated yet. A negative value -N indicates
the process was killed by signal N (Unix only).
"""
if self.outThread:
# Thread.join() blocks the main thread until outThread is finished
# wake up once a second in case a keyboard interrupt is sent
count = 0
while self.outThread.isAlive():
self.outThread.join(timeout=1)
count += 1
if timeout and count > timeout:
return None
return self.proc.wait()
# TODO Remove this method when consumers have been fixed
def waitForFinish(self, timeout=None):
print >> sys.stderr, "MOZPROCESS WARNING: ProcessHandler.waitForFinish() is deprecated, " \
"use ProcessHandler.wait() instead"
return self.wait(timeout=timeout)
### Private methods from here on down. Thar be dragons.
if isWin:
# Windows Specific private functions are defined in this block
PeekNamedPipe = ctypes.windll.kernel32.PeekNamedPipe
GetLastError = ctypes.windll.kernel32.GetLastError
def _readWithTimeout(self, f, timeout):
if timeout is None:
# shortcut to allow callers to pass in "None" for no timeout.
return (f.readline(), False)
x = msvcrt.get_osfhandle(f.fileno())
l = ctypes.c_long()
done = time.time() + timeout
while time.time() < done:
if self.PeekNamedPipe(x, None, 0, None, ctypes.byref(l), None) == 0:
err = self.GetLastError()
if err == 38 or err == 109: # ERROR_HANDLE_EOF || ERROR_BROKEN_PIPE
return ('', False)
else:
raise OSError("readWithTimeout got error: %d", err)
if l.value > 0:
# we're assuming that the output is line-buffered,
# which is not unreasonable
return (f.readline(), False)
time.sleep(0.01)
return ('', True)
else:
# Generic
def _readWithTimeout(self, f, timeout):
while True:
try:
(r, w, e) = select.select([f], [], [], timeout)
except:
# return a blank line
return ('', True)
if len(r) == 0:
return ('', True)
output = os.read(f.fileno(), 4096)
if not output:
output = self.read_buffer
self.read_buffer = ''
return (output, False)
self.read_buffer += output
if '\n' not in self.read_buffer:
time.sleep(0.01)
continue
tmp = self.read_buffer.split('\n')
lines, self.read_buffer = tmp[:-1], tmp[-1]
real_lines = [x for x in lines if x != '']
if not real_lines:
time.sleep(0.01)
continue
break
return ('\n'.join(lines), False)
@property
def pid(self):
return self.proc.pid
### default output handlers
### these should be callables that take the output line
def print_output(line):
print line
class StoreOutput(object):
"""accumulate stdout"""
def __init__(self):
self.output = []
def __call__(self, line):
self.output.append(line)
class LogOutput(object):
"""pass output to a file"""
def __init__(self, filename):
self.filename = filename
self.file = None
def __call__(self, line):
if self.file is None:
self.file = file(self.filename, 'a')
self.file.write(line + '\n')
self.file.flush()
def __del__(self):
if self.file is not None:
self.file.close()
### front end class with the default handlers
class ProcessHandler(ProcessHandlerMixin):
"""
Convenience class for handling processes with default output handlers.
If no processOutputLine keyword argument is specified, write all
output to stdout. Otherwise, the function specified by this argument
will be called for each line of output; the output will not be written
to stdout automatically.
If storeOutput==True, the output produced by the process will be saved
as self.output.
If logfile is not None, the output produced by the process will be
appended to the given file.
"""
def __init__(self, cmd, logfile=None, storeOutput=True, **kwargs):
kwargs.setdefault('processOutputLine', [])
# Print to standard output only if no outputline provided
if not kwargs['processOutputLine']:
kwargs['processOutputLine'].append(print_output)
if logfile:
logoutput = LogOutput(logfile)
kwargs['processOutputLine'].append(logoutput)
self.output = None
if storeOutput:
storeoutput = StoreOutput()
self.output = storeoutput.output
kwargs['processOutputLine'].append(storeoutput)
ProcessHandlerMixin.__init__(self, cmd, **kwargs)