--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/CSP2/CSP2_env/env-d9b9114564458d9d-741b3de822f2aaca6c6caa4325c4afce/lib/python3.8/multiprocessing/queues.py	Tue Mar 18 17:55:14 2025 -0400
@@ -0,0 +1,368 @@
+#
+# Module implementing queues
+#
+# multiprocessing/queues.py
+#
+# Copyright (c) 2006-2008, R Oudkerk
+# Licensed to PSF under a Contributor Agreement.
+#
+
+__all__ = ['Queue', 'SimpleQueue', 'JoinableQueue']
+
+import sys
+import os
+import threading
+import collections
+import time
+import weakref
+import errno
+
+from queue import Empty, Full
+
+import _multiprocessing
+
+from . import connection
+from . import context
+_ForkingPickler = context.reduction.ForkingPickler
+
+from .util import debug, info, Finalize, register_after_fork, is_exiting
+
+#
+# Queue type using a pipe, buffer and thread
+#
+
+class Queue(object):
+
+    def __init__(self, maxsize=0, *, ctx):
+        if maxsize <= 0:
+            # Can raise ImportError (see issues #3770 and #23400)
+            from .synchronize import SEM_VALUE_MAX as maxsize
+        self._maxsize = maxsize
+        self._reader, self._writer = connection.Pipe(duplex=False)
+        self._rlock = ctx.Lock()
+        self._opid = os.getpid()
+        if sys.platform == 'win32':
+            self._wlock = None
+        else:
+            self._wlock = ctx.Lock()
+        self._sem = ctx.BoundedSemaphore(maxsize)
+        # For use by concurrent.futures
+        self._ignore_epipe = False
+
+        self._after_fork()
+
+        if sys.platform != 'win32':
+            register_after_fork(self, Queue._after_fork)
+
+    def __getstate__(self):
+        context.assert_spawning(self)
+        return (self._ignore_epipe, self._maxsize, self._reader, self._writer,
+                self._rlock, self._wlock, self._sem, self._opid)
+
+    def __setstate__(self, state):
+        (self._ignore_epipe, self._maxsize, self._reader, self._writer,
+         self._rlock, self._wlock, self._sem, self._opid) = state
+        self._after_fork()
+
+    def _after_fork(self):
+        debug('Queue._after_fork()')
+        self._notempty = threading.Condition(threading.Lock())
+        self._buffer = collections.deque()
+        self._thread = None
+        self._jointhread = None
+        self._joincancelled = False
+        self._closed = False
+        self._close = None
+        self._send_bytes = self._writer.send_bytes
+        self._recv_bytes = self._reader.recv_bytes
+        self._poll = self._reader.poll
+
+    def put(self, obj, block=True, timeout=None):
+        if self._closed:
+            raise ValueError(f"Queue {self!r} is closed")
+        if not self._sem.acquire(block, timeout):
+            raise Full
+
+        with self._notempty:
+            if self._thread is None:
+                self._start_thread()
+            self._buffer.append(obj)
+            self._notempty.notify()
+
+    def get(self, block=True, timeout=None):
+        if self._closed:
+            raise ValueError(f"Queue {self!r} is closed")
+        if block and timeout is None:
+            with self._rlock:
+                res = self._recv_bytes()
+            self._sem.release()
+        else:
+            if block:
+                deadline = time.monotonic() + timeout
+            if not self._rlock.acquire(block, timeout):
+                raise Empty
+            try:
+                if block:
+                    timeout = deadline - time.monotonic()
+                    if not self._poll(timeout):
+                        raise Empty
+                elif not self._poll():
+                    raise Empty
+                res = self._recv_bytes()
+                self._sem.release()
+            finally:
+                self._rlock.release()
+        # unserialize the data after having released the lock
+        return _ForkingPickler.loads(res)
+
+    def qsize(self):
+        # Raises NotImplementedError on Mac OSX because of broken sem_getvalue()
+        return self._maxsize - self._sem._semlock._get_value()
+
+    def empty(self):
+        return not self._poll()
+
+    def full(self):
+        return self._sem._semlock._is_zero()
+
+    def get_nowait(self):
+        return self.get(False)
+
+    def put_nowait(self, obj):
+        return self.put(obj, False)
+
+    def close(self):
+        self._closed = True
+        try:
+            self._reader.close()
+        finally:
+            close = self._close
+            if close:
+                self._close = None
+                close()
+
+    def join_thread(self):
+        debug('Queue.join_thread()')
+        assert self._closed, "Queue {0!r} not closed".format(self)
+        if self._jointhread:
+            self._jointhread()
+
+    def cancel_join_thread(self):
+        debug('Queue.cancel_join_thread()')
+        self._joincancelled = True
+        try:
+            self._jointhread.cancel()
+        except AttributeError:
+            pass
+
+    def _start_thread(self):
+        debug('Queue._start_thread()')
+
+        # Start thread which transfers data from buffer to pipe
+        self._buffer.clear()
+        self._thread = threading.Thread(
+            target=Queue._feed,
+            args=(self._buffer, self._notempty, self._send_bytes,
+                  self._wlock, self._writer.close, self._ignore_epipe,
+                  self._on_queue_feeder_error, self._sem),
+            name='QueueFeederThread'
+        )
+        self._thread.daemon = True
+
+        debug('doing self._thread.start()')
+        self._thread.start()
+        debug('... done self._thread.start()')
+
+        if not self._joincancelled:
+            self._jointhread = Finalize(
+                self._thread, Queue._finalize_join,
+                [weakref.ref(self._thread)],
+                exitpriority=-5
+                )
+
+        # Send sentinel to the thread queue object when garbage collected
+        self._close = Finalize(
+            self, Queue._finalize_close,
+            [self._buffer, self._notempty],
+            exitpriority=10
+            )
+
+    @staticmethod
+    def _finalize_join(twr):
+        debug('joining queue thread')
+        thread = twr()
+        if thread is not None:
+            thread.join()
+            debug('... queue thread joined')
+        else:
+            debug('... queue thread already dead')
+
+    @staticmethod
+    def _finalize_close(buffer, notempty):
+        debug('telling queue thread to quit')
+        with notempty:
+            buffer.append(_sentinel)
+            notempty.notify()
+
+    @staticmethod
+    def _feed(buffer, notempty, send_bytes, writelock, close, ignore_epipe,
+              onerror, queue_sem):
+        debug('starting thread to feed data to pipe')
+        nacquire = notempty.acquire
+        nrelease = notempty.release
+        nwait = notempty.wait
+        bpopleft = buffer.popleft
+        sentinel = _sentinel
+        if sys.platform != 'win32':
+            wacquire = writelock.acquire
+            wrelease = writelock.release
+        else:
+            wacquire = None
+
+        while 1:
+            try:
+                nacquire()
+                try:
+                    if not buffer:
+                        nwait()
+                finally:
+                    nrelease()
+                try:
+                    while 1:
+                        obj = bpopleft()
+                        if obj is sentinel:
+                            debug('feeder thread got sentinel -- exiting')
+                            close()
+                            return
+
+                        # serialize the data before acquiring the lock
+                        obj = _ForkingPickler.dumps(obj)
+                        if wacquire is None:
+                            send_bytes(obj)
+                        else:
+                            wacquire()
+                            try:
+                                send_bytes(obj)
+                            finally:
+                                wrelease()
+                except IndexError:
+                    pass
+            except Exception as e:
+                if ignore_epipe and getattr(e, 'errno', 0) == errno.EPIPE:
+                    return
+                # Since this runs in a daemon thread the resources it uses
+                # may be become unusable while the process is cleaning up.
+                # We ignore errors which happen after the process has
+                # started to cleanup.
+                if is_exiting():
+                    info('error in queue thread: %s', e)
+                    return
+                else:
+                    # Since the object has not been sent in the queue, we need
+                    # to decrease the size of the queue. The error acts as
+                    # if the object had been silently removed from the queue
+                    # and this step is necessary to have a properly working
+                    # queue.
+                    queue_sem.release()
+                    onerror(e, obj)
+
+    @staticmethod
+    def _on_queue_feeder_error(e, obj):
+        """
+        Private API hook called when feeding data in the background thread
+        raises an exception.  For overriding by concurrent.futures.
+        """
+        import traceback
+        traceback.print_exc()
+
+
+_sentinel = object()
+
+#
+# A queue type which also supports join() and task_done() methods
+#
+# Note that if you do not call task_done() for each finished task then
+# eventually the counter's semaphore may overflow causing Bad Things
+# to happen.
+#
+
+class JoinableQueue(Queue):
+
+    def __init__(self, maxsize=0, *, ctx):
+        Queue.__init__(self, maxsize, ctx=ctx)
+        self._unfinished_tasks = ctx.Semaphore(0)
+        self._cond = ctx.Condition()
+
+    def __getstate__(self):
+        return Queue.__getstate__(self) + (self._cond, self._unfinished_tasks)
+
+    def __setstate__(self, state):
+        Queue.__setstate__(self, state[:-2])
+        self._cond, self._unfinished_tasks = state[-2:]
+
+    def put(self, obj, block=True, timeout=None):
+        if self._closed:
+            raise ValueError(f"Queue {self!r} is closed")
+        if not self._sem.acquire(block, timeout):
+            raise Full
+
+        with self._notempty, self._cond:
+            if self._thread is None:
+                self._start_thread()
+            self._buffer.append(obj)
+            self._unfinished_tasks.release()
+            self._notempty.notify()
+
+    def task_done(self):
+        with self._cond:
+            if not self._unfinished_tasks.acquire(False):
+                raise ValueError('task_done() called too many times')
+            if self._unfinished_tasks._semlock._is_zero():
+                self._cond.notify_all()
+
+    def join(self):
+        with self._cond:
+            if not self._unfinished_tasks._semlock._is_zero():
+                self._cond.wait()
+
+#
+# Simplified Queue type -- really just a locked pipe
+#
+
+class SimpleQueue(object):
+
+    def __init__(self, *, ctx):
+        self._reader, self._writer = connection.Pipe(duplex=False)
+        self._rlock = ctx.Lock()
+        self._poll = self._reader.poll
+        if sys.platform == 'win32':
+            self._wlock = None
+        else:
+            self._wlock = ctx.Lock()
+
+    def empty(self):
+        return not self._poll()
+
+    def __getstate__(self):
+        context.assert_spawning(self)
+        return (self._reader, self._writer, self._rlock, self._wlock)
+
+    def __setstate__(self, state):
+        (self._reader, self._writer, self._rlock, self._wlock) = state
+        self._poll = self._reader.poll
+
+    def get(self):
+        with self._rlock:
+            res = self._reader.recv_bytes()
+        # unserialize the data after having released the lock
+        return _ForkingPickler.loads(res)
+
+    def put(self, obj):
+        # serialize the data before acquiring the lock
+        obj = _ForkingPickler.dumps(obj)
+        if self._wlock is None:
+            # writes to a message oriented win32 pipe are atomic
+            self._writer.send_bytes(obj)
+        else:
+            with self._wlock:
+                self._writer.send_bytes(obj)