._B/$ : d Z dZddlZddlmZ ddlZddlZddlZddl m Z ddlZddlZddl mZ ddlZddlZddlmZ ej Zda G d d Zd Z ej e dZd Z G d de Z G d d Zd Z G d de Z G d de Z! G d de Z" G d de Z#d Z$d Z% d'dZ&d(dZ' G d d ej( Z)da*da+d! Z,d" Z- G d# d$ej. Z/ G d% d&ej0 Z1dS ))a- Implements ProcessPoolExecutor. The following diagram and text describe the data-flow through the system: |======================= In-process =====================|== Out-of-process ==| +----------+ +----------+ +--------+ +-----------+ +---------+ | | => | Work Ids | | | | Call Q | | Process | | | +----------+ | | +-----------+ | Pool | | | | ... | | | | ... | +---------+ | | | 6 | => | | => | 5, call() | => | | | | | 7 | | | | ... | | | | Process | | ... | | Local | +-----------+ | Process | | Pool | +----------+ | Worker | | #1..n | | Executor | | Thread | | | | | +----------- + | | +-----------+ | | | | <=> | Work Items | <=> | | <= | Result Q | <= | | | | +------------+ | | +-----------+ | | | | | 6: call() | | | | ... | | | | | | future | | | | 4, result | | | | | | ... | | | | 3, except | | | +----------+ +------------+ +--------+ +-----------+ +---------+ Executor.submit() called: - creates a uniquely numbered _WorkItem and adds it to the "Work Items" dict - adds the id of the _WorkItem to the "Work Ids" queue Local worker thread: - reads work ids from the "Work Ids" queue and looks up the corresponding WorkItem from the "Work Items" dict: if the work item has been cancelled then it is simply removed from the dict, otherwise it is repackaged as a _CallItem and put in the "Call Q". New _CallItems are put in the "Call Q" until "Call Q" is full. NOTE: the size of the "Call Q" is kept small because calls placed in the "Call Q" can no longer be cancelled with Future.cancel(). - reads _ResultItems from "Result Q", updates the future stored in the "Work Items" dict and deletes the dict entry Process #1..n: - reads _CallItems from "Call Q", executes the calls, and puts the resulting _ResultItems in "Result Q" z"Brian Quinlan (brian@sweetapp.com) N)_base)Queue)partial)format_exceptionFc &