FM / multiprocessing

/snap/core18/2999/usr/lib/python3.6/multiprocessing/

/snap/core18/2999/usr/lib/python3.6/multiprocessing

Name	Size	Mode	Actions
dummy/	-	0755	rm
__pycache__/	-	0755	rm
connection.py	30891	0644	edit dl rm
context.py	10917	0644	edit dl rm
forkserver.py	8694	0644	edit dl rm
heap.py	8319	0644	edit dl rm
managers.py	38151	0644	edit dl rm
pool.py	26059	0644	edit dl rm
popen_fork.py	2307	0644	edit dl rm
popen_forkserver.py	1956	0644	edit dl rm
popen_spawn_posix.py	1904	0644	edit dl rm
popen_spawn_win32.py	2999	0644	edit dl rm
process.py	9211	0644	edit dl rm
queues.py	10763	0644	edit dl rm
reduction.py	9226	0644	edit dl rm
resource_sharer.py	5325	0644	edit dl rm
semaphore_tracker.py	5394	0644	edit dl rm
sharedctypes.py	6245	0644	edit dl rm
spawn.py	8863	0644	edit dl rm
synchronize.py	12050	0644	edit dl rm
util.py	11886	0644	edit dl rm
__init__.py	923	0644	edit dl rm

Edit: /snap/core18/2999/usr/lib/python3.6/multiprocessing/synchronize.py (12050B)

#
# Module implementing synchronization primitives
#
# multiprocessing/synchronize.py
#
# Copyright (c) 2006-2008, R Oudkerk
# Licensed to PSF under a Contributor Agreement.
#

__all__ = [
    'Lock', 'RLock', 'Semaphore', 'BoundedSemaphore', 'Condition', 'Event'
    ]

import threading
import sys
import tempfile
import _multiprocessing
import time

from . import context
from . import process
from . import util

# Try to import the mp.synchronize module cleanly, if it fails
# raise ImportError for platforms lacking a working sem_open implementation.
# See issue 3770
try:
    from _multiprocessing import SemLock, sem_unlink
except (ImportError):
    raise ImportError("This platform lacks a functioning sem_open" +
                      " implementation, therefore, the required" +
                      " synchronization primitives needed will not" +
                      " function, see issue 3770.")

#
# Constants
#

RECURSIVE_MUTEX, SEMAPHORE = list(range(2))
SEM_VALUE_MAX = _multiprocessing.SemLock.SEM_VALUE_MAX

#
# Base class for semaphores and mutexes; wraps `_multiprocessing.SemLock`
#

class SemLock(object):

_rand = tempfile._RandomNameSequence()

def __init__(self, kind, value, maxvalue, *, ctx):
        if ctx is None:
            ctx = context._default_context.get_context()
        name = ctx.get_start_method()
        unlink_now = sys.platform == 'win32' or name == 'fork'
        for i in range(100):
            try:
                sl = self._semlock = _multiprocessing.SemLock(
                    kind, value, maxvalue, self._make_name(),
                    unlink_now)
            except FileExistsError:
                pass
            else:
                break
        else:
            raise FileExistsError('cannot find name for semaphore')

util.debug('created semlock with handle %s' % sl.handle)
        self._make_methods()

if sys.platform != 'win32':
            def _after_fork(obj):
                obj._semlock._after_fork()
            util.register_after_fork(self, _after_fork)

if self._semlock.name is not None:
            # We only get here if we are on Unix with forking
            # disabled.  When the object is garbage collected or the
            # process shuts down we unlink the semaphore name
            from .semaphore_tracker import register
            register(self._semlock.name)
            util.Finalize(self, SemLock._cleanup, (self._semlock.name,),
                          exitpriority=0)

@staticmethod
    def _cleanup(name):
        from .semaphore_tracker import unregister
        sem_unlink(name)
        unregister(name)

def _make_methods(self):
        self.acquire = self._semlock.acquire
        self.release = self._semlock.release

def __enter__(self):
        return self._semlock.__enter__()

def __exit__(self, *args):
        return self._semlock.__exit__(*args)

def __getstate__(self):
        context.assert_spawning(self)
        sl = self._semlock
        if sys.platform == 'win32':
            h = context.get_spawning_popen().duplicate_for_child(sl.handle)
        else:
            h = sl.handle
        return (h, sl.kind, sl.maxvalue, sl.name)

def __setstate__(self, state):
        self._semlock = _multiprocessing.SemLock._rebuild(*state)
        util.debug('recreated blocker with handle %r' % state[0])
        self._make_methods()

@staticmethod
    def _make_name():
        return '%s-%s' % (process.current_process()._config['semprefix'],
                          next(SemLock._rand))

#
# Semaphore
#

class Semaphore(SemLock):

def __init__(self, value=1, *, ctx):
        SemLock.__init__(self, SEMAPHORE, value, SEM_VALUE_MAX, ctx=ctx)

def get_value(self):
        return self._semlock._get_value()

def __repr__(self):
        try:
            value = self._semlock._get_value()
        except Exception:
            value = 'unknown'
        return '<%s(value=%s)>' % (self.__class__.__name__, value)

#
# Bounded semaphore
#

class BoundedSemaphore(Semaphore):

def __init__(self, value=1, *, ctx):
        SemLock.__init__(self, SEMAPHORE, value, value, ctx=ctx)

def __repr__(self):
        try:
            value = self._semlock._get_value()
        except Exception:
            value = 'unknown'
        return '<%s(value=%s, maxvalue=%s)>' % \
               (self.__class__.__name__, value, self._semlock.maxvalue)

#
# Non-recursive lock
#

class Lock(SemLock):

def __init__(self, *, ctx):
        SemLock.__init__(self, SEMAPHORE, 1, 1, ctx=ctx)

def __repr__(self):
        try:
            if self._semlock._is_mine():
                name = process.current_process().name
                if threading.current_thread().name != 'MainThread':
                    name += '|' + threading.current_thread().name
            elif self._semlock._get_value() == 1:
                name = 'None'
            elif self._semlock._count() > 0:
                name = 'SomeOtherThread'
            else:
                name = 'SomeOtherProcess'
        except Exception:
            name = 'unknown'
        return '<%s(owner=%s)>' % (self.__class__.__name__, name)

#
# Recursive lock
#

class RLock(SemLock):

def __init__(self, *, ctx):
        SemLock.__init__(self, RECURSIVE_MUTEX, 1, 1, ctx=ctx)

def __repr__(self):
        try:
            if self._semlock._is_mine():
                name = process.current_process().name
                if threading.current_thread().name != 'MainThread':
                    name += '|' + threading.current_thread().name
                count = self._semlock._count()
            elif self._semlock._get_value() == 1:
                name, count = 'None', 0
            elif self._semlock._count() > 0:
                name, count = 'SomeOtherThread', 'nonzero'
            else:
                name, count = 'SomeOtherProcess', 'nonzero'
        except Exception:
            name, count = 'unknown', 'unknown'
        return '<%s(%s, %s)>' % (self.__class__.__name__, name, count)

#
# Condition variable
#

class Condition(object):

def __init__(self, lock=None, *, ctx):
        self._lock = lock or ctx.RLock()
        self._sleeping_count = ctx.Semaphore(0)
        self._woken_count = ctx.Semaphore(0)
        self._wait_semaphore = ctx.Semaphore(0)
        self._make_methods()

def __getstate__(self):
        context.assert_spawning(self)
        return (self._lock, self._sleeping_count,
                self._woken_count, self._wait_semaphore)

def __setstate__(self, state):
        (self._lock, self._sleeping_count,
         self._woken_count, self._wait_semaphore) = state
        self._make_methods()

def __enter__(self):
        return self._lock.__enter__()

def __exit__(self, *args):
        return self._lock.__exit__(*args)

def _make_methods(self):
        self.acquire = self._lock.acquire
        self.release = self._lock.release

def __repr__(self):
        try:
            num_waiters = (self._sleeping_count._semlock._get_value() -
                           self._woken_count._semlock._get_value())
        except Exception:
            num_waiters = 'unknown'
        return '<%s(%s, %s)>' % (self.__class__.__name__, self._lock, num_waiters)

def wait(self, timeout=None):
        assert self._lock._semlock._is_mine(), \
               'must acquire() condition before using wait()'

# indicate that this thread is going to sleep
        self._sleeping_count.release()

# release lock
        count = self._lock._semlock._count()
        for i in range(count):
            self._lock.release()

try:
            # wait for notification or timeout
            return self._wait_semaphore.acquire(True, timeout)
        finally:
            # indicate that this thread has woken
            self._woken_count.release()

# reacquire lock
            for i in range(count):
                self._lock.acquire()

def notify(self):
        assert self._lock._semlock._is_mine(), 'lock is not owned'
        assert not self._wait_semaphore.acquire(False)

# to take account of timeouts since last notify() we subtract
        # woken_count from sleeping_count and rezero woken_count
        while self._woken_count.acquire(False):
            res = self._sleeping_count.acquire(False)
            assert res

if self._sleeping_count.acquire(False): # try grabbing a sleeper
            self._wait_semaphore.release()      # wake up one sleeper
            self._woken_count.acquire()         # wait for the sleeper to wake

# rezero _wait_semaphore in case a timeout just happened
            self._wait_semaphore.acquire(False)

def notify_all(self):
        assert self._lock._semlock._is_mine(), 'lock is not owned'
        assert not self._wait_semaphore.acquire(False)

# to take account of timeouts since last notify*() we subtract
        # woken_count from sleeping_count and rezero woken_count
        while self._woken_count.acquire(False):
            res = self._sleeping_count.acquire(False)
            assert res

sleepers = 0
        while self._sleeping_count.acquire(False):
            self._wait_semaphore.release()        # wake up one sleeper
            sleepers += 1

if sleepers:
            for i in range(sleepers):
                self._woken_count.acquire()       # wait for a sleeper to wake

# rezero wait_semaphore in case some timeouts just happened
            while self._wait_semaphore.acquire(False):
                pass

def wait_for(self, predicate, timeout=None):
        result = predicate()
        if result:
            return result
        if timeout is not None:
            endtime = time.monotonic() + timeout
        else:
            endtime = None
            waittime = None
        while not result:
            if endtime is not None:
                waittime = endtime - time.monotonic()
                if waittime <= 0:
                    break
            self.wait(waittime)
            result = predicate()
        return result

#
# Event
#

class Event(object):

def __init__(self, *, ctx):
        self._cond = ctx.Condition(ctx.Lock())
        self._flag = ctx.Semaphore(0)

def is_set(self):
        with self._cond:
            if self._flag.acquire(False):
                self._flag.release()
                return True
            return False

def set(self):
        with self._cond:
            self._flag.acquire(False)
            self._flag.release()
            self._cond.notify_all()

def clear(self):
        with self._cond:
            self._flag.acquire(False)

def wait(self, timeout=None):
        with self._cond:
            if self._flag.acquire(False):
                self._flag.release()
            else:
                self._cond.wait(timeout)

if self._flag.acquire(False):
                self._flag.release()
                return True
            return False

#
# Barrier
#

class Barrier(threading.Barrier):

def __init__(self, parties, action=None, timeout=None, *, ctx):
        import struct
        from .heap import BufferWrapper
        wrapper = BufferWrapper(struct.calcsize('i') * 2)
        cond = ctx.Condition()
        self.__setstate__((parties, action, timeout, cond, wrapper))
        self._state = 0
        self._count = 0

def __setstate__(self, state):
        (self._parties, self._action, self._timeout,
         self._cond, self._wrapper) = state
        self._array = self._wrapper.create_memoryview().cast('i')

def __getstate__(self):
        return (self._parties, self._action, self._timeout,
                self._cond, self._wrapper)

@property
    def _state(self):
        return self._array[0]

@_state.setter
    def _state(self, value):
        self._array[0] = value

@property
    def _count(self):
        return self._array[1]

@_count.setter
    def _count(self, value):
        self._array[1] = value

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