Question

我有一个简单的python多处理模块实现

if __name__ == '__main__':
jobs = []

while True:
    for i in range(40):
        # fetch one by one from redis queue
        #item = item from redis queue
        p = Process(name='worker '+str(i), target=worker, args=(item,))

        # if p is not running, start p
        if not p.is_alive():
            jobs.append(p)
            p.start()

    for j in jobs:
        j.join()
        jobs.remove(j)


def worker(url_data):
    """worker function"""
    print url_data['link']

我希望此代码能够做到：

在无限循环中运行，继续等待Redis队列。
如果Redis队列不为空，则获取项目。
创建40个multiprocess.Process，而不是更多
如果进程已完成处理，则启动新进程，以便~40进程始终在运行。

我读到这一点，以避免应该绑定（加入）父节点的僵尸进程，这是我期望在第二个循环中实现的。但问题是，在启动它时会产生40个进程，工作人员完成处理并进入僵尸状态，直到所有当前生成的进程尚未完成，然后在＆＃34;而True＆＃34;的下一次迭代中，相同的模式继续。

所以我的问题是：我怎样才能避免僵尸进程。并在40中完成后立即生成新进程

Answer 1

对于您所描述的任务，通常最好使用this.state.isSelected使用不同的方法。

您可以让主进程获取数据，工作人员可以处理它。

来自Python Docs

的

var React = require('react');
var SelectBox = require('./select-box');

var ListItem = React.createClass({
    getInitialState: function() {
        return {
            isSelected: false
        };
    },

    toggleSelected: function () {
        if (this.state.isSelected == true) {
            this.setState({
                isSelected: false
            })
        } else {
            this.setState({
                isSelected: true
            })
        }
    },

    handleClick: function(listItem) {
        this.toggleSelected();
        this.props.onListItemChange(listItem.props.value);

        var unboundForEach = Array.prototype.forEach,
            forEach = Function.prototype.call.bind(unboundForEach);

        forEach(document.querySelectorAll('ul.cs-select li'), function (el) {

            // below is trying to 
            // make sure that when a user clicks on a list
            // item in the SelectableList, then all the *other*
            // list items get class="selected" removed.
            // this works for the first time that you move through the 
            // list clicking the other items, but then, on the second
            // pass through, starts to fail, requiring *two clicks* before the
            // list item is selected again.
            // maybe there's a better more "reactive" method of doing this?

            if (el.dataset.index != listItem.props.index && el.classList.contains('selected') ) {
                el.classList.remove('selected');
            }
        });
    },

    render: function() {
        return (
            <li ref={"listSel"+this.props.key}
                data-value={this.props.value}
                data-index={this.props.index}
                className={this.state.isSelected == true ? 'selected' : '' } 
                onClick={this.handleClick.bind(null, this)}>
                {this.props.content}
            </li>
        );
    }
});

var SelectableList = React.createClass({

    render: function() {

        var listItems = this.props.options.map(function(opt, index) {
            return <ListItem key={index} index={index} 
                        value={opt.value} content={opt.label}
                        onListItemChange={this.props.onListItemChange.bind(null, index)} />;
        }, this);

        return <ul className="cs-select">{ listItems }</ul>;
    }

})

var CustomSelect = React.createClass({

    getInitialState: function () {
        return {
            selectedOption: ''
        }
    },

    handleListItemChange: function(listIndex, listItem) {
        this.setState({
            selectedOption: listItem.props.value
        })
    },

    render: function () {

        var options = [{value:"One", label: "One"},{value:"Two", label: "Two"},{value:"Three", label: "Three"}];

        return (
            <div className="group">
                <div className="cs-select">
                    <SelectableList options={options} 
                        onListItemChange={this.handleListItemChange} />
                    <SelectBox className="cs-select" 
                        initialValue={this.state.selectedOption} 
                        fieldName="custom-select" options={options}/>
                </div>
            </div>
        )
    } 
})

module.exports = CustomSelect;

示例

Pool

我还建议您使用Pool代替def f(x): return x*x if __name__ == '__main__': pool = Pool(processes=4) # start 4 worker processes result = pool.apply_async(f, [10]) # evaluate "f(10)" asynchronously print result.get(timeout=1) # prints "100" unless your computer is *very* slow print pool.map(f, range(10)) # prints "[0, 1, 4,..., 81]"，因为您的任务似乎是异步。

你的代码大概是：

imap

python多处理僵尸进程

1 个答案: