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Getting rid of this ancient stuff.
author Guido van Rossum <guido@python.org>
date Wed, 05 Aug 1998 21:10:09 +0000
parents 760dcf197048
children acfffe14628e
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8e5223680a9d Remove all uses of \sectcode; we can now use logical markup everywhere.
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1 \section{Standard Module \module{Queue}}
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2 \declaremodule{standard}{Queue}
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3
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4 \modulesynopsis{A stynchronized queue class.}
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8 The \module{Queue} module implements a multi-producer, multi-consumer
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9 FIFO queue. It is especially useful in threads programming when
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10 information must be exchanged safely between multiple threads. The
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11 \class{Queue} class in this module implements all the required locking
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12 semantics. It depends on the availability of thread support in
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13 Python.
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14
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15 The \module{Queue} module defines the following class and exception:
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16
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17
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18 \begin{classdesc}{Queue}{maxsize}
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19 Constructor for the class. \var{maxsize} is an integer that sets the
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20 upperbound limit on the number of items that can be placed in the
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21 queue. Insertion will block once this size has been reached, until
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22 queue items are consumed. If \var{maxsize} is less than or equal to
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23 zero, the queue size is infinite.
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24 \end{classdesc}
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25
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26 \begin{excdesc}{Empty}
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27 Exception raised when non-blocking get (e.g. \method{get_nowait()}) is
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28 called on a \class{Queue} object which is empty, or for which the
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29 emptyiness cannot be determined (i.e. because the appropriate locks
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30 cannot be acquired).
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31 \end{excdesc}
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32
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33 \subsection{Queue Objects}
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34 \label{QueueObjects}
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35
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36 Class \class{Queue} implements queue objects and has the methods
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37 described below. This class can be derived from in order to implement
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38 other queue organizations (e.g. stack) but the inheritable interface
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39 is not described here. See the source code for details. The public
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40 methods are:
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41
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42 \begin{methoddesc}{qsize}{}
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43 Returns the approximate size of the queue. Because of multithreading
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44 semantics, this number is not reliable.
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45 \end{methoddesc}
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46
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47 \begin{methoddesc}{empty}{}
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48 Returns \code{1} if the queue is empty, \code{0} otherwise. Because
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49 of multithreading semantics, this is not reliable.
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50 \end{methoddesc}
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51
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52 \begin{methoddesc}{full}{}
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53 Returns \code{1} if the queue is full, \code{0} otherwise. Because of
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54 multithreading semantics, this is not reliable.
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55 \end{methoddesc}
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56
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57 \begin{methoddesc}{put}{item}
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58 Puts \var{item} into the queue.
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59 \end{methoddesc}
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60
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61 \begin{methoddesc}{get}{}
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62 Gets and returns an item from the queue, blocking if necessary until
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63 one is available.
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64 \end{methoddesc}
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65
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66 \begin{methoddesc}{get_nowait}{}
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67 Gets and returns an item from the queue if one is immediately
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68 available. Raises an \exception{Empty} exception if the queue is
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69 empty or if the queue's emptiness cannot be determined.
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70 \end{methoddesc}