Python errno.ESRCH Examples

def memory_maps(self):
        try:
            raw = cext.proc_memory_maps(self.pid)
        except OSError as err:
            # XXX - can't use wrap_exceptions decorator as we're
            # returning a generator; probably needs refactoring.
            if err.errno in ACCESS_DENIED_ERRSET:
                raise AccessDenied(self.pid, self._name)
            if err.errno == errno.ESRCH:
                raise NoSuchProcess(self.pid, self._name)
            raise
        else:
            for addr, perm, path, rss in raw:
                path = convert_dos_path(path)
                if not PY3:
                    assert isinstance(path, unicode), type(path)
                    path = py2_strencode(path)
                addr = hex(addr)
                yield (addr, perm, path, rss) 

def ppid_map():
    """Obtain a {pid: ppid, ...} dict for all running processes in
    one shot. Used to speed up Process.children().
    """
    ret = {}
    procfs_path = get_procfs_path()
    for pid in pids():
        try:
            with open_binary("%s/%s/stat" % (procfs_path, pid)) as f:
                data = f.read()
        except EnvironmentError as err:
            # Note: we should be able to access /stat for all processes
            # aka it's unlikely we'll bump into EPERM, which is good.
            if err.errno not in (errno.ENOENT, errno.ESRCH):
                raise
        else:
            rpar = data.rfind(b')')
            dset = data[rpar + 2:].split()
            ppid = int(dset[1])
            ret[pid] = ppid
    return ret 

def catch_zombie(proc):
    """There are some poor C APIs which incorrectly raise ESRCH when
    the process is still alive or it's a zombie, or even RuntimeError
    (those who don't set errno). This is here in order to solve:
    https://github.com/giampaolo/psutil/issues/1044
    """
    try:
        yield
    except (OSError, RuntimeError) as err:
        if isinstance(err, RuntimeError) or err.errno == errno.ESRCH:
            try:
                # status() is not supposed to lie and correctly detect
                # zombies so if it raises ESRCH it's true.
                status = proc.status()
            except NoSuchProcess:
                raise err
            else:
                if status == _common.STATUS_ZOMBIE:
                    raise ZombieProcess(proc.pid, proc._name, proc._ppid)
                else:
                    raise AccessDenied(proc.pid, proc._name)
        else:
            raise 

def del_route(self, prefix):
        if not self.platform_supported or self._simulated_interfaces:
            return False
        if self._table_nr == -1:
            return False
        dst = packet_common.ip_prefix_str(prefix)
        try:
            self.ipr.route('del', table=self._table_nr, dst=dst, proto=RTPROT_RIFT,
                           priority=RTPRIORITY_RIFT)
        except pyroute2.netlink.exceptions.NetlinkError as err:
            if err.code != errno.ESRCH:  # It is not an error to delete a non-existing route
                self.error("Netlink error \"%s\" deleting route to %s", err, dst)
            return False
        except OSError as err:
            self.error("OS error \"%s\" deleting route to %s", err, dst)
            return False
        else:
            self.debug("Delete route to %s", prefix)
            return True 

def wrap_exceptions(fun):
    """Decorator which translates bare OSError exceptions into
    NoSuchProcess and AccessDenied.
    """
    @functools.wraps(fun)
    def wrapper(self, *args, **kwargs):
        try:
            return fun(self, *args, **kwargs)
        except OSError as err:
            if err.errno == errno.ESRCH:
                raise NoSuchProcess(self.pid, self._name)
            if err.errno in (errno.EPERM, errno.EACCES):
                raise AccessDenied(self.pid, self._name)
            raise
        except cext.ZombieProcessError:
            raise ZombieProcess(self.pid, self._name, self._ppid)
    return wrapper 

def exe(self):
        try:
            return readlink("%s/%s/exe" % (self._procfs_path, self.pid))
        except OSError as err:
            if err.errno in (errno.ENOENT, errno.ESRCH):
                # no such file error; might be raised also if the
                # path actually exists for system processes with
                # low pids (about 0-20)
                if os.path.lexists("%s/%s" % (self._procfs_path, self.pid)):
                    return ""
                else:
                    if not pid_exists(self.pid):
                        raise NoSuchProcess(self.pid, self._name)
                    else:
                        raise ZombieProcess(self.pid, self._name, self._ppid)
            if err.errno in (errno.EPERM, errno.EACCES):
                raise AccessDenied(self.pid, self._name)
            raise 

def wrap_exceptions(fun):
    """Decorator which translates bare OSError and IOError exceptions
    into NoSuchProcess and AccessDenied.
    """
    @functools.wraps(fun)
    def wrapper(self, *args, **kwargs):
        try:
            return fun(self, *args, **kwargs)
        except EnvironmentError as err:
            if err.errno in (errno.EPERM, errno.EACCES):
                raise AccessDenied(self.pid, self._name)
            # ESRCH (no such process) can be raised on read() if
            # process is gone in the meantime.
            if err.errno == errno.ESRCH:
                raise NoSuchProcess(self.pid, self._name)
            # ENOENT (no such file or directory) can be raised on open().
            if err.errno == errno.ENOENT and not os.path.exists("%s/%s" % (
                    self._procfs_path, self.pid)):
                raise NoSuchProcess(self.pid, self._name)
            # Note: zombies will keep existing under /proc until they're
            # gone so there's no way to distinguish them in here.
            raise
    return wrapper 

def wrap_exceptions_procfs(inst):
    """Same as above, for routines relying on reading /proc fs."""
    try:
        yield
    except EnvironmentError as err:
        # ENOENT (no such file or directory) gets raised on open().
        # ESRCH (no such process) can get raised on read() if
        # process is gone in meantime.
        if err.errno in (errno.ENOENT, errno.ESRCH):
            if not pid_exists(inst.pid):
                raise NoSuchProcess(inst.pid, inst._name)
            else:
                raise ZombieProcess(inst.pid, inst._name, inst._ppid)
        if err.errno in (errno.EPERM, errno.EACCES):
            raise AccessDenied(inst.pid, inst._name)
        raise 

def kill_process(pid, sig=None):
    """Try to send signal to given process."""
    if sig is None:
        sig = signal.SIGKILL  # set default lazily, otherwise importing fails on Windows
    try:
        os.kill(pid, sig)
    except OSError as e:
        if e.errno == errno.ESRCH:
            # process itself returned and exited before killing
            logging.debug(
                "Failure %s while killing process %s with signal %s: %s",
                e.errno,
                pid,
                sig,
                e.strerror,
            )
        else:
            logging.warning(
                "Failure %s while killing process %s with signal %s: %s",
                e.errno,
                pid,
                sig,
                e.strerror,
            ) 

def __exit__(self, exc_type, exc_value, traceback):
        try:
            self.child.terminate()
        except OSError as error:
            if error.errno == errno.ESRCH:
                return
            raise

        while True:
            line = self.child.stderr.readline()
            if not line:
                break
            sys.stderr.write(line)

        self.child.wait()
        shutil.rmtree(self.data_path) 

def kill_worker(self, pid, sig):
        """\
        Kill a worker

        :attr pid: int, worker pid
        :attr sig: `signal.SIG*` value
         """
        try:
            os.kill(pid, sig)
        except OSError as e:
            if e.errno == errno.ESRCH:
                try:
                    worker = self.WORKERS.pop(pid)
                    worker.tmp.close()
                    self.cfg.worker_exit(self, worker)
                    return
                except (KeyError, OSError):
                    return
            raise 

def get_all_inodes(self):
        inodes = {}
        for pid in pids():
            try:
                inodes.update(self.get_proc_inodes(pid))
            except OSError as err:
                # os.listdir() is gonna raise a lot of access denied
                # exceptions in case of unprivileged user; that's fine
                # as we'll just end up returning a connection with PID
                # and fd set to None anyway.
                # Both netstat -an and lsof does the same so it's
                # unlikely we can do any better.
                # ENOENT just means a PID disappeared on us.
                if err.errno not in (
                        errno.ENOENT, errno.ESRCH, errno.EPERM, errno.EACCES):
                    raise
        return inodes 

def ppid_map():
    """Obtain a {pid: ppid, ...} dict for all running processes in
    one shot. Used to speed up Process.children().
    """
    ret = {}
    procfs_path = get_procfs_path()
    for pid in pids():
        try:
            with open_binary("%s/%s/stat" % (procfs_path, pid)) as f:
                data = f.read()
        except EnvironmentError as err:
            # Note: we should be able to access /stat for all processes
            # aka it's unlikely we'll bump into EPERM, which is good.
            if err.errno not in (errno.ENOENT, errno.ESRCH):
                raise
        else:
            rpar = data.rfind(b')')
            dset = data[rpar + 2:].split()
            ppid = int(dset[1])
            ret[pid] = ppid
    return ret 

def wrap_exceptions(fun):
    """Decorator which translates bare OSError and IOError exceptions
    into NoSuchProcess and AccessDenied.
    """
    @functools.wraps(fun)
    def wrapper(self, *args, **kwargs):
        try:
            return fun(self, *args, **kwargs)
        except EnvironmentError as err:
            if err.errno in (errno.EPERM, errno.EACCES):
                raise AccessDenied(self.pid, self._name)
            # ESRCH (no such process) can be raised on read() if
            # process is gone in the meantime.
            if err.errno == errno.ESRCH:
                raise NoSuchProcess(self.pid, self._name)
            # ENOENT (no such file or directory) can be raised on open().
            if err.errno == errno.ENOENT and not os.path.exists("%s/%s" % (
                    self._procfs_path, self.pid)):
                raise NoSuchProcess(self.pid, self._name)
            # Note: zombies will keep existing under /proc until they're
            # gone so there's no way to distinguish them in here.
            raise
    return wrapper 

def exe(self):
        try:
            return readlink("%s/%s/exe" % (self._procfs_path, self.pid))
        except OSError as err:
            if err.errno in (errno.ENOENT, errno.ESRCH):
                # no such file error; might be raised also if the
                # path actually exists for system processes with
                # low pids (about 0-20)
                if os.path.lexists("%s/%s" % (self._procfs_path, self.pid)):
                    return ""
                else:
                    if not pid_exists(self.pid):
                        raise NoSuchProcess(self.pid, self._name)
                    else:
                        raise ZombieProcess(self.pid, self._name, self._ppid)
            if err.errno in (errno.EPERM, errno.EACCES):
                raise AccessDenied(self.pid, self._name)
            raise 

def _send_signal(self, sig):
            assert not self.pid < 0, self.pid
            if self.pid == 0:
                # see "man 2 kill"
                raise ValueError(
                    "preventing sending signal to process with PID 0 as it "
                    "would affect every process in the process group of the "
                    "calling process (os.getpid()) instead of PID 0")
            try:
                os.kill(self.pid, sig)
            except OSError as err:
                if err.errno == errno.ESRCH:
                    if OPENBSD and pid_exists(self.pid):
                        # We do this because os.kill() lies in case of
                        # zombie processes.
                        raise ZombieProcess(self.pid, self._name, self._ppid)
                    else:
                        self._gone = True
                        raise NoSuchProcess(self.pid, self._name)
                if err.errno in (errno.EPERM, errno.EACCES):
                    raise AccessDenied(self.pid, self._name)
                raise 

def wrap_exceptions(fun):
    """Call callable into a try/except clause and translate ENOENT,
    EACCES and EPERM in NoSuchProcess or AccessDenied exceptions.
    """
    @functools.wraps(fun)
    def wrapper(self, *args, **kwargs):
        try:
            return fun(self, *args, **kwargs)
        except EnvironmentError as err:
            # support for private module import
            if (NoSuchProcess is None or AccessDenied is None or
                    ZombieProcess is None):
                raise
            # ENOENT (no such file or directory) gets raised on open().
            # ESRCH (no such process) can get raised on read() if
            # process is gone in meantime.
            if err.errno in (errno.ENOENT, errno.ESRCH):
                if not pid_exists(self.pid):
                    raise NoSuchProcess(self.pid, self._name)
                else:
                    raise ZombieProcess(self.pid, self._name, self._ppid)
            if err.errno in (errno.EPERM, errno.EACCES):
                raise AccessDenied(self.pid, self._name)
            raise
    return wrapper 

def wrap_exceptions(fun):
    def wrapper(self, *args, **kwargs):
        try:
            return fun(self, *args, **kwargs)
        except OSError as err:
            from psutil._pswindows import ACCESS_DENIED_SET
            if err.errno in ACCESS_DENIED_SET:
                raise psutil.AccessDenied(None, None)
            if err.errno == errno.ESRCH:
                raise psutil.NoSuchProcess(None, None)
            raise
    return wrapper


# ===================================================================
# System APIs
# =================================================================== 

def catch_zombie(proc):
    """There are some poor C APIs which incorrectly raise ESRCH when
    the process is still alive or it's a zombie, or even RuntimeError
    (those who don't set errno). This is here in order to solve:
    https://github.com/giampaolo/psutil/issues/1044
    """
    try:
        yield
    except (OSError, RuntimeError) as err:
        if isinstance(err, RuntimeError) or err.errno == errno.ESRCH:
            try:
                # status() is not supposed to lie and correctly detect
                # zombies so if it raises ESRCH it's true.
                status = proc.status()
            except NoSuchProcess:
                raise err
            else:
                if status == _common.STATUS_ZOMBIE:
                    raise ZombieProcess(proc.pid, proc._name, proc._ppid)
                else:
                    raise AccessDenied(proc.pid, proc._name)
        else:
            raise 

def test_killError(self):
        """
        If L{kill} raises an exception other than L{OSError} with errno set to
        C{ESRCH}, the exception is passed up to the caller of
        L{FilesystemLock.lock}.
        """
        def fakeKill(pid, signal):
            raise OSError(errno.EPERM, None)
        self.patch(lockfile, 'kill', fakeKill)

        lockf = self.mktemp()

        # Make it appear locked so it has to use readlink
        lockfile.symlink(str(43125), lockf)

        lock = lockfile.FilesystemLock(lockf)
        exc = self.assertRaises(OSError, lock.lock)
        self.assertEqual(exc.errno, errno.EPERM)
        self.assertFalse(lock.locked) 

def test_rmlinkError(self):
        """
        An exception raised by L{rmlink} other than C{ENOENT} is passed up
        to the caller of L{FilesystemLock.lock}.
        """
        def fakeRmlink(name):
            raise OSError(errno.ENOSYS, None)
        self.patch(lockfile, 'rmlink', fakeRmlink)

        def fakeKill(pid, signal):
            if signal != 0:
                raise OSError(errno.EPERM, None)
            if pid == 43125:
                raise OSError(errno.ESRCH, None)
        self.patch(lockfile, 'kill', fakeKill)

        lockf = self.mktemp()

        # Make it appear locked so it has to use readlink
        lockfile.symlink(str(43125), lockf)

        lock = lockfile.FilesystemLock(lockf)
        exc = self.assertRaises(OSError, lock.lock)
        self.assertEqual(exc.errno, errno.ENOSYS)
        self.assertFalse(lock.locked) 

def catch_zombie(proc):
    """There are some poor C APIs which incorrectly raise ESRCH when
    the process is still alive or it's a zombie, or even RuntimeError
    (those who don't set errno). This is here in order to solve:
    https://github.com/giampaolo/psutil/issues/1044
    """
    try:
        yield
    except (OSError, RuntimeError) as err:
        if isinstance(err, RuntimeError) or err.errno == errno.ESRCH:
            try:
                # status() is not supposed to lie and correctly detect
                # zombies so if it raises ESRCH it's true.
                status = proc.status()
            except NoSuchProcess:
                raise err
            else:
                if status == _common.STATUS_ZOMBIE:
                    raise ZombieProcess(proc.pid, proc._name, proc._ppid)
                else:
                    raise AccessDenied(proc.pid, proc._name)
        else:
            raise 

def test_uncleanlyAcquire(self):
        """
        If a lock was held by a process which no longer exists, it can be
        acquired, the C{clean} attribute is set to C{False}, and the
        C{locked} attribute is set to C{True}.
        """
        owner = 12345

        def fakeKill(pid, signal):
            if signal != 0:
                raise OSError(errno.EPERM, None)
            if pid == owner:
                raise OSError(errno.ESRCH, None)

        lockf = self.mktemp()
        self.patch(lockfile, 'kill', fakeKill)
        lockfile.symlink(str(owner), lockf)

        lock = lockfile.FilesystemLock(lockf)
        self.assertTrue(lock.lock())
        self.assertFalse(lock.clean)
        self.assertTrue(lock.locked)

        self.assertEqual(lockfile.readlink(lockf), str(os.getpid())) 

def _pid_exists(self):
        if not self.pid:
            return False

        if sublime.platform() == "windows":
            taskkill = subprocess.Popen(['C:\\Windows\\system32\\tasklist.exe', '/FI', 'PID eq %s' % self.pid, '/FO', 'CSV'], stdout=subprocess.PIPE, stderr=subprocess.PIPE, shell=True)
            (stdout, stderr) = taskkill.communicate()

            failed = taskkill.returncode == 127 or stderr
            found = str(self.pid) in CrossPlatformCodecs.force_decode(stdout)

            return found or failed
        else:
            try:
                os.kill(self.pid, 0)
            except OSError as err:
                if err.errno == errno.ESRCH:
                    return False
                elif err.errno == errno.EPERM:
                    return True
                else:
                    raise
            else:
                return True 

def close_all(self):
        tasks = self._active_tasks[:]
        # this must be set after getting active tasks as it causes
        # thread objects to get out of the list too soon
        self._exit.set()
        if tasks and hasattr(tasks[0], 'terminate'):
            # we're dealing with subprocesses
            for t in tasks:
                try:
                    if not _BSD:
                        t.terminate()
                    else:
                        # XXX - On FreeBSD using SIGTERM doesn't work
                        # as the process hangs on kqueue.control() or
                        # select.select(). Use SIGKILL instead.
                        os.kill(t.pid, signal.SIGKILL)
                except OSError as err:
                    if err.errno != errno.ESRCH:
                        raise

        self._wait_for_tasks(tasks)
        del self._active_tasks[:]
        FTPServer.close_all(self) 

def _wait_for_tasks(self, tasks):
        """Wait for threads or subprocesses to terminate."""
        warn = logger.warning
        for t in tasks:
            t.join(self.join_timeout)
            if t.is_alive():
                # Thread or process is still alive. If it's a process
                # attempt to send SIGKILL as last resort.
                # Set timeout to None so that we will exit immediately
                # in case also other threads/processes are hanging.
                self.join_timeout = None
                if hasattr(t, 'terminate'):
                    msg = "could not terminate process %r" % t
                    if not _BSD:
                        warn(msg + "; sending SIGKILL as last resort")
                        try:
                            os.kill(t.pid, signal.SIGKILL)
                        except OSError as err:
                            if err.errno != errno.ESRCH:
                                raise
                    else:
                        warn(msg)
                else:
                    warn("thread %r didn't terminate; ignoring it", t) 

def close_all(self):
        tasks = self._active_tasks[:]
        # this must be set after getting active tasks as it causes
        # thread objects to get out of the list too soon
        self._exit.set()
        if tasks and hasattr(tasks[0], 'terminate'):
            # we're dealing with subprocesses
            for t in tasks:
                try:
                    if not _BSD:
                        t.terminate()
                    else:
                        # XXX - On FreeBSD using SIGTERM doesn't work
                        # as the process hangs on kqueue.control() or
                        # select.select(). Use SIGKILL instead.
                        os.kill(t.pid, signal.SIGKILL)
                except OSError as err:
                    if err.errno != errno.ESRCH:
                        raise

        self._wait_for_tasks(tasks)
        del self._active_tasks[:]
        FTPServer.close_all(self) 

def _wait_for_tasks(self, tasks):
        """Wait for threads or subprocesses to terminate."""
        warn = logger.warning
        for t in tasks:
            t.join(self.join_timeout)
            if t.is_alive():
                # Thread or process is still alive. If it's a process
                # attempt to send SIGKILL as last resort.
                # Set timeout to None so that we will exit immediately
                # in case also other threads/processes are hanging.
                self.join_timeout = None
                if hasattr(t, 'terminate'):
                    msg = "could not terminate process %r" % t
                    if not _BSD:
                        warn(msg + "; sending SIGKILL as last resort")
                        try:
                            os.kill(t.pid, signal.SIGKILL)
                        except OSError as err:
                            if err.errno != errno.ESRCH:
                                raise
                    else:
                        warn(msg)
                else:
                    warn("thread %r didn't terminate; ignoring it", t) 

def test_contextManagerDoesntExist(self):
        """
        When used as a context manager, a L{PIDFile} will replace the
        underlying PIDFile rather than raising L{AlreadyRunningError} if the
        contained PID file exists but refers to a non-running PID.
        """
        pidFile = PIDFile(DummyFilePath())
        pidFile._write(1337)

        def kill(pid, signal):
            raise OSError(errno.ESRCH, "No such process")

        self.patch(_pidfile, "kill", kill)

        e = self.assertRaises(StalePIDFileError, pidFile.isRunning)
        self.assertEqual(str(e), "PID file refers to non-existing process")

        with pidFile:
            self.assertEqual(pidFile.read(), getpid()) 

def signalProcess(self, signalID):
        """
        Send the given signal C{signalID} to the process. It'll translate a
        few signals ('HUP', 'STOP', 'INT', 'KILL', 'TERM') from a string
        representation to its int value, otherwise it'll pass directly the
        value provided

        @type signalID: C{str} or C{int}
        """
        if signalID in ('HUP', 'STOP', 'INT', 'KILL', 'TERM'):
            signalID = getattr(signal, 'SIG%s' % (signalID,))
        if self.pid is None:
            raise ProcessExitedAlready()
        try:
            os.kill(self.pid, signalID)
        except OSError as e:
            if e.errno == errno.ESRCH:
                raise ProcessExitedAlready()
            else:
                raise