diff options
author | Ori Bernstein <ori@eigenstate.org> | 2021-06-14 00:00:37 +0000 |
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committer | Ori Bernstein <ori@eigenstate.org> | 2021-06-14 00:00:37 +0000 |
commit | a73a964e51247ed169d322c725a3a18859f109a3 (patch) | |
tree | 3f752d117274d444bda44e85609aeac1acf313f3 /sys/lib/python/Queue.py | |
parent | e64efe273fcb921a61bf27d33b230c4e64fcd425 (diff) |
python, hg: tow outside the environment.
they've served us well, and can ride off into the sunset.
Diffstat (limited to 'sys/lib/python/Queue.py')
-rw-r--r-- | sys/lib/python/Queue.py | 215 |
1 files changed, 0 insertions, 215 deletions
diff --git a/sys/lib/python/Queue.py b/sys/lib/python/Queue.py deleted file mode 100644 index 79b0abf14..000000000 --- a/sys/lib/python/Queue.py +++ /dev/null @@ -1,215 +0,0 @@ -"""A multi-producer, multi-consumer queue.""" - -from time import time as _time -from collections import deque - -__all__ = ['Empty', 'Full', 'Queue'] - -class Empty(Exception): - "Exception raised by Queue.get(block=0)/get_nowait()." - pass - -class Full(Exception): - "Exception raised by Queue.put(block=0)/put_nowait()." - pass - -class Queue: - """Create a queue object with a given maximum size. - - If maxsize is <= 0, the queue size is infinite. - """ - def __init__(self, maxsize=0): - try: - import threading - except ImportError: - import dummy_threading as threading - self._init(maxsize) - # mutex must be held whenever the queue is mutating. All methods - # that acquire mutex must release it before returning. mutex - # is shared between the three conditions, so acquiring and - # releasing the conditions also acquires and releases mutex. - self.mutex = threading.Lock() - # Notify not_empty whenever an item is added to the queue; a - # thread waiting to get is notified then. - self.not_empty = threading.Condition(self.mutex) - # Notify not_full whenever an item is removed from the queue; - # a thread waiting to put is notified then. - self.not_full = threading.Condition(self.mutex) - # Notify all_tasks_done whenever the number of unfinished tasks - # drops to zero; thread waiting to join() is notified to resume - self.all_tasks_done = threading.Condition(self.mutex) - self.unfinished_tasks = 0 - - def task_done(self): - """Indicate that a formerly enqueued task is complete. - - Used by Queue consumer threads. For each get() used to fetch a task, - a subsequent call to task_done() tells the queue that the processing - on the task is complete. - - If a join() is currently blocking, it will resume when all items - have been processed (meaning that a task_done() call was received - for every item that had been put() into the queue). - - Raises a ValueError if called more times than there were items - placed in the queue. - """ - self.all_tasks_done.acquire() - try: - unfinished = self.unfinished_tasks - 1 - if unfinished <= 0: - if unfinished < 0: - raise ValueError('task_done() called too many times') - self.all_tasks_done.notifyAll() - self.unfinished_tasks = unfinished - finally: - self.all_tasks_done.release() - - def join(self): - """Blocks until all items in the Queue have been gotten and processed. - - The count of unfinished tasks goes up whenever an item is added to the - queue. The count goes down whenever a consumer thread calls task_done() - to indicate the item was retrieved and all work on it is complete. - - When the count of unfinished tasks drops to zero, join() unblocks. - """ - self.all_tasks_done.acquire() - try: - while self.unfinished_tasks: - self.all_tasks_done.wait() - finally: - self.all_tasks_done.release() - - def qsize(self): - """Return the approximate size of the queue (not reliable!).""" - self.mutex.acquire() - n = self._qsize() - self.mutex.release() - return n - - def empty(self): - """Return True if the queue is empty, False otherwise (not reliable!).""" - self.mutex.acquire() - n = self._empty() - self.mutex.release() - return n - - def full(self): - """Return True if the queue is full, False otherwise (not reliable!).""" - self.mutex.acquire() - n = self._full() - self.mutex.release() - return n - - def put(self, item, block=True, timeout=None): - """Put an item into the queue. - - If optional args 'block' is true and 'timeout' is None (the default), - block if necessary until a free slot is available. If 'timeout' is - a positive number, it blocks at most 'timeout' seconds and raises - the Full exception if no free slot was available within that time. - Otherwise ('block' is false), put an item on the queue if a free slot - is immediately available, else raise the Full exception ('timeout' - is ignored in that case). - """ - self.not_full.acquire() - try: - if not block: - if self._full(): - raise Full - elif timeout is None: - while self._full(): - self.not_full.wait() - else: - if timeout < 0: - raise ValueError("'timeout' must be a positive number") - endtime = _time() + timeout - while self._full(): - remaining = endtime - _time() - if remaining <= 0.0: - raise Full - self.not_full.wait(remaining) - self._put(item) - self.unfinished_tasks += 1 - self.not_empty.notify() - finally: - self.not_full.release() - - def put_nowait(self, item): - """Put an item into the queue without blocking. - - Only enqueue the item if a free slot is immediately available. - Otherwise raise the Full exception. - """ - return self.put(item, False) - - def get(self, block=True, timeout=None): - """Remove and return an item from the queue. - - If optional args 'block' is true and 'timeout' is None (the default), - block if necessary until an item is available. If 'timeout' is - a positive number, it blocks at most 'timeout' seconds and raises - the Empty exception if no item was available within that time. - Otherwise ('block' is false), return an item if one is immediately - available, else raise the Empty exception ('timeout' is ignored - in that case). - """ - self.not_empty.acquire() - try: - if not block: - if self._empty(): - raise Empty - elif timeout is None: - while self._empty(): - self.not_empty.wait() - else: - if timeout < 0: - raise ValueError("'timeout' must be a positive number") - endtime = _time() + timeout - while self._empty(): - remaining = endtime - _time() - if remaining <= 0.0: - raise Empty - self.not_empty.wait(remaining) - item = self._get() - self.not_full.notify() - return item - finally: - self.not_empty.release() - - def get_nowait(self): - """Remove and return an item from the queue without blocking. - - Only get an item if one is immediately available. Otherwise - raise the Empty exception. - """ - return self.get(False) - - # Override these methods to implement other queue organizations - # (e.g. stack or priority queue). - # These will only be called with appropriate locks held - - # Initialize the queue representation - def _init(self, maxsize): - self.maxsize = maxsize - self.queue = deque() - - def _qsize(self): - return len(self.queue) - - # Check whether the queue is empty - def _empty(self): - return not self.queue - - # Check whether the queue is full - def _full(self): - return self.maxsize > 0 and len(self.queue) == self.maxsize - - # Put a new item in the queue - def _put(self, item): - self.queue.append(item) - - # Get an item from the queue - def _get(self): - return self.queue.popleft() |