diff options
Diffstat (limited to 'testing/mozbase/mozprocess/mozprocess/processhandler.py')
| -rw-r--r-- | testing/mozbase/mozprocess/mozprocess/processhandler.py | 1079 |
1 files changed, 1079 insertions, 0 deletions
diff --git a/testing/mozbase/mozprocess/mozprocess/processhandler.py b/testing/mozbase/mozprocess/mozprocess/processhandler.py new file mode 100644 index 000000000..661a7820e --- /dev/null +++ b/testing/mozbase/mozprocess/mozprocess/processhandler.py @@ -0,0 +1,1079 @@ +# 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/. + +from __future__ import absolute_import + +import os +import signal +import subprocess +import sys +import threading +import time +import traceback +from Queue import Queue, Empty +from datetime import datetime + +__all__ = ['ProcessHandlerMixin', 'ProcessHandler', 'LogOutput', + 'StoreOutput', 'StreamOutput'] + +# 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: + from ctypes import sizeof, addressof, c_ulong, byref, WinError, c_longlong + from . 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 or list of functions to be called for + each line of output produced by the process (defaults to an empty + list). + :param processStderrLine: function or list of functions to be called + for each line of error output - stderr - produced by the process + (defaults to an empty list). If this is not specified, stderr lines + will be sent to the *processOutputLine* callbacks. + :param onTimeout: function or list of functions to be called when the process times out. + :param onFinish: function or list of functions 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 + TIMEOUT_BEFORE_SIGKILL = 1.0 + + 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: + print >> sys.stderr, args + raise + + def debug(self, msg): + if not MOZPROCESS_DEBUG: + return + thread = threading.current_thread().name + print("DBG::MOZPROC PID:{} ({}) | {}".format(self.pid, thread, msg)) + + def __del__(self, _maxint=sys.maxint): + if isWin: + handle = getattr(self, '_handle', None) + if handle: + if hasattr(self, '_internal_poll'): + self._internal_poll(_deadstate=_maxint) + else: + self.poll(_deadstate=sys.maxint) + if handle or self._job or self._io_port: + self._cleanup() + else: + subprocess.Popen.__del__(self) + + def kill(self, sig=None): + if isWin: + if not self._ignore_children and self._handle and self._job: + self.debug("calling TerminateJobObject") + winprocess.TerminateJobObject(self._job, winprocess.ERROR_CONTROL_C_EXIT) + self.returncode = winprocess.GetExitCodeProcess(self._handle) + elif self._handle: + self.debug("calling TerminateProcess") + try: + winprocess.TerminateProcess(self._handle, winprocess.ERROR_CONTROL_C_EXIT) + except: + traceback.print_exc() + raise OSError("Could not terminate process") + finally: + winprocess.GetExitCodeProcess(self._handle) + self._cleanup() + else: + def send_sig(sig): + pid = self.detached_pid or self.pid + if not self._ignore_children: + try: + os.killpg(pid, sig) + except BaseException as e: + # Error 3 is a "no such process" failure, which is fine because the + # application might already have been terminated itself. Any other + # error would indicate a problem in killing the process. + if getattr(e, "errno", None) != 3: + print >> sys.stderr, "Could not terminate process: %s" % self.pid + raise + else: + os.kill(pid, sig) + + if sig is None and isPosix: + # ask the process for termination and wait a bit + send_sig(signal.SIGTERM) + limit = time.time() + self.TIMEOUT_BEFORE_SIGKILL + while time.time() <= limit: + if self.poll() is not None: + # process terminated nicely + break + time.sleep(0.02) + else: + # process did not terminate - send SIGKILL to force + send_sig(signal.SIGKILL) + else: + # a signal was explicitly set or not posix + send_sig(sig or signal.SIGKILL) + + self.returncode = self.wait() + self._cleanup() + return self.returncode + + def poll(self): + """ Popen.poll + Check if child process has terminated. Set and return returncode attribute. + """ + # If we have a handle, the process is alive + if isWin and getattr(self, '_handle', None): + return None + + return subprocess.Popen.poll(self) + + 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 a job or create nested jobs. + can_create_job = winprocess.CanCreateJobObject() + can_nest_jobs = self._can_nest_jobs() + + # Ensure we write a warning message if we are falling back + if not (can_create_job or can_nest_jobs) 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 can_create_job: + creationflags |= winprocess.CREATE_BREAKAWAY_FROM_JOB + if not (can_create_job or can_nest_jobs): + # 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 (can_create_job or can_nest_jobs): + 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() + + # Per: + # https://msdn.microsoft.com/en-us/library/windows/desktop/hh448388%28v=vs.85%29.aspx + # Nesting jobs came in with windows versions starting with 6.2 according to the table + # on this page: + # https://msdn.microsoft.com/en-us/library/ms724834%28v=vs.85%29.aspx + def _can_nest_jobs(self): + winver = sys.getwindowsversion() + return (winver.major > 6 or + winver.major == 6 and winver.minor >= 2) + + # 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 + + self.debug("start polling IO completion port") + + 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, \ + "WARNING | IO Completion Port failed to signal process shutdown" + 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, but no guarantee of success" + + self.kill() + self._process_events.put({self.pid: 'FINISHED'}) + break + + 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" + self._process_events.put({self.pid: 'FINISHED'}) + 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: + self.debug("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 + self.debug("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 + self.debug("new process detected with pid value: %s" % pid.value) + elif msgid.value == winprocess.JOB_OBJECT_MSG_EXIT_PROCESS: + self.debug("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 + self.debug("process id %s exited 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 + self.debug("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 + + threadalive = False + if hasattr(self, "_procmgrthread"): + threadalive = self._procmgrthread.is_alive() + if self._job and threadalive and threading.current_thread() != self._procmgrthread: + self.debug("waiting with IO completion port") + # 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 + 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.debug("received 'FINISHED' from _procmgrthread") + self._process_events.task_done() + except: + traceback.print_exc() + raise OSError("IO Completion Port failed to signal process shutdown") + finally: + if self._handle: + self.returncode = winprocess.GetExitCodeProcess(self._handle) + self._cleanup() + + else: + # Not managing with job objects, so all we can reasonably do + # is call waitforsingleobject and hope for the best + self.debug("waiting without IO completion port") + + if not self._ignore_children: + self.debug("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 as 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 self.returncode + + 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=(), + processStderrLine=(), + onTimeout=(), + onFinish=(), + **kwargs): + self.cmd = cmd + self.args = args + self.cwd = cwd + self.didTimeout = False + self._ignore_children = ignore_children + self.keywordargs = kwargs + self.read_buffer = '' + + if env is None: + env = os.environ.copy() + self.env = env + + # handlers + def to_callable_list(arg): + if callable(arg): + arg = [arg] + return CallableList(arg) + + processOutputLine = to_callable_list(processOutputLine) + processStderrLine = to_callable_list(processStderrLine) + onTimeout = to_callable_list(onTimeout) + onFinish = to_callable_list(onFinish) + + def on_timeout(): + self.didTimeout = True + if kill_on_timeout: + self.kill() + onTimeout.insert(0, on_timeout) + + self._stderr = subprocess.STDOUT + if processStderrLine: + self._stderr = subprocess.PIPE + self.reader = ProcessReader(stdout_callback=processOutputLine, + stderr_callback=processStderrLine, + finished_callback=onFinish, + timeout_callback=onTimeout) + + # 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 is not 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 + + # default arguments + args = dict(stdout=subprocess.PIPE, + stderr=self._stderr, + 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) + + if isPosix: + # Keep track of the initial process group in case the process detaches itself + self.proc.pgid = os.getpgid(self.proc.pid) + self.proc.detached_pid = None + + 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) + """ + if not hasattr(self, 'proc'): + raise RuntimeError("Calling kill() on a non started process is not" + " allowed.") + self.proc.kill(sig=sig) + + # When we kill the the managed process we also have to wait for the + # reader thread to be finished. Otherwise consumers would have to assume + # that it still has not completely shutdown. + return self.wait() + + def poll(self): + """Check if child process has terminated + + Returns the current returncode value: + - None if the process hasn't terminated yet + - A negative number if the process was killed by signal N (Unix only) + - '0' if the process ended without failures + + """ + # Ensure that we first check for the reader status. Otherwise + # we might mark the process as finished while output is still getting + # processed. + if not hasattr(self, 'proc'): + raise RuntimeError("Calling poll() on a non started process is not" + " allowed.") + elif self.reader.is_alive(): + return None + elif hasattr(self.proc, "returncode"): + return self.proc.returncode + else: + return self.proc.poll() + + 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. + """ + # this method is kept for backward compatibility + if not hasattr(self, 'proc'): + self.run(timeout=timeout, outputTimeout=outputTimeout) + # self.run will call this again + return + if not self.reader.is_alive(): + self.reader.timeout = timeout + self.reader.output_timeout = outputTimeout + self.reader.start(self.proc) + + 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 value: + - None if the process hasn't terminated yet + - A negative number if the process was killed by signal N (Unix only) + - '0' if the process ended without failures + + """ + if self.reader.thread and self.reader.thread is not threading.current_thread(): + # Thread.join() blocks the main thread until the reader thread is finished + # wake up once a second in case a keyboard interrupt is sent + count = 0 + while self.reader.is_alive(): + self.reader.thread.join(timeout=1) + count += 1 + if timeout and count > timeout: + return None + + self.returncode = self.proc.wait() + return self.returncode + + # 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) + + @property + def pid(self): + return self.proc.pid + + def check_for_detached(self, new_pid): + """Check if the current process has been detached and mark it appropriately. + + In case of application restarts the process can spawn itself into a new process group. + From now on the process can no longer be tracked by mozprocess anymore and has to be + marked as detached. If the consumer of mozprocess still knows the new process id it could + check for the detached state. + + new_pid is the new process id of the child process. + """ + if not self.proc: + return + + if isPosix: + new_pgid = None + try: + new_pgid = os.getpgid(new_pid) + except OSError as e: + # Do not consume errors except "No such process" + if e.errno != 3: + raise + + if new_pgid and new_pgid != self.proc.pgid: + self.proc.detached_pid = new_pid + print >> sys.stdout, \ + 'Child process with id "%s" has been marked as detached because it is no ' \ + 'longer in the managed process group. Keeping reference to the process id ' \ + '"%s" which is the new child process.' % (self.pid, new_pid) + + +class CallableList(list): + + def __call__(self, *args, **kwargs): + for e in self: + e(*args, **kwargs) + + def __add__(self, lst): + return CallableList(list.__add__(self, lst)) + + +class ProcessReader(object): + + def __init__(self, stdout_callback=None, stderr_callback=None, + finished_callback=None, timeout_callback=None, + timeout=None, output_timeout=None): + self.stdout_callback = stdout_callback or (lambda line: True) + self.stderr_callback = stderr_callback or (lambda line: True) + self.finished_callback = finished_callback or (lambda: True) + self.timeout_callback = timeout_callback or (lambda: True) + self.timeout = timeout + self.output_timeout = output_timeout + self.thread = None + + def _create_stream_reader(self, name, stream, queue, callback): + thread = threading.Thread(name=name, + target=self._read_stream, + args=(stream, queue, callback)) + thread.daemon = True + thread.start() + return thread + + def _read_stream(self, stream, queue, callback): + while True: + line = stream.readline() + if not line: + break + queue.put((line, callback)) + stream.close() + + def start(self, proc): + queue = Queue() + stdout_reader = None + if proc.stdout: + stdout_reader = self._create_stream_reader('ProcessReaderStdout', + proc.stdout, + queue, + self.stdout_callback) + stderr_reader = None + if proc.stderr and proc.stderr != proc.stdout: + stderr_reader = self._create_stream_reader('ProcessReaderStderr', + proc.stderr, + queue, + self.stderr_callback) + self.thread = threading.Thread(name='ProcessReader', + target=self._read, + args=(stdout_reader, + stderr_reader, + queue)) + self.thread.daemon = True + self.thread.start() + + def _read(self, stdout_reader, stderr_reader, queue): + start_time = time.time() + timed_out = False + timeout = self.timeout + if timeout is not None: + timeout += start_time + output_timeout = self.output_timeout + if output_timeout is not None: + output_timeout += start_time + + while (stdout_reader and stdout_reader.is_alive()) \ + or (stderr_reader and stderr_reader.is_alive()): + has_line = True + try: + line, callback = queue.get(True, 0.02) + except Empty: + has_line = False + now = time.time() + if not has_line: + if output_timeout is not None and now > output_timeout: + timed_out = True + break + else: + if output_timeout is not None: + output_timeout = now + self.output_timeout + callback(line.rstrip()) + if timeout is not None and now > timeout: + timed_out = True + break + # process remaining lines to read + while not queue.empty(): + line, callback = queue.get(False) + callback(line.rstrip()) + if timed_out: + self.timeout_callback() + if stdout_reader: + stdout_reader.join() + if stderr_reader: + stderr_reader.join() + if not timed_out: + self.finished_callback() + + def is_alive(self): + if self.thread: + return self.thread.is_alive() + return False + +# default output handlers +# these should be callables that take the output line + + +class StoreOutput(object): + """accumulate stdout""" + + def __init__(self): + self.output = [] + + def __call__(self, line): + self.output.append(line) + + +class StreamOutput(object): + """pass output to a stream and flush""" + + def __init__(self, stream): + self.stream = stream + + def __call__(self, line): + try: + self.stream.write(line + '\n') + except UnicodeDecodeError: + # TODO: Workaround for bug #991866 to make sure we can display when + # when normal UTF-8 display is failing + self.stream.write(line.decode('iso8859-1') + '\n') + self.stream.flush() + + +class LogOutput(StreamOutput): + """pass output to a file""" + + def __init__(self, filename): + self.file_obj = open(filename, 'a') + StreamOutput.__init__(self, self.file_obj) + + def __del__(self): + if self.file_obj is not None: + self.file_obj.close() + + +# front end class with the default handlers + + +class ProcessHandler(ProcessHandlerMixin): + """ + Convenience class for handling processes with default output handlers. + + By default, all output is sent to stdout. This can be disabled by setting + the *stream* argument to None. + + If processOutputLine keyword argument is specified the function or the + list of functions specified by this argument will be called for each line + of output; the output will not be written to stdout automatically then + if stream is True (the default). + + 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, stream=True, storeOutput=True, + **kwargs): + kwargs.setdefault('processOutputLine', []) + if callable(kwargs['processOutputLine']): + kwargs['processOutputLine'] = [kwargs['processOutputLine']] + + if logfile: + logoutput = LogOutput(logfile) + kwargs['processOutputLine'].append(logoutput) + + if stream is True: + # Print to standard output only if no outputline provided + if not kwargs['processOutputLine']: + kwargs['processOutputLine'].append(StreamOutput(sys.stdout)) + elif stream: + streamoutput = StreamOutput(stream) + kwargs['processOutputLine'].append(streamoutput) + + self.output = None + if storeOutput: + storeoutput = StoreOutput() + self.output = storeoutput.output + kwargs['processOutputLine'].append(storeoutput) + + ProcessHandlerMixin.__init__(self, cmd, **kwargs) |