我如何知道我的promise.all是否并行运行? [英] How can I tell if my promise.all is running in parallel?

问题描述

我有以下Promise.all示例.我想知道它是否在lambda.invoke方面并行"运行?以及我该如何测试某些东西是否正在并行运行?

I have the following Promise.all example. I was wondering if it was operating in "parallel" in regards to the lambda.invoke? And how can I test if something is running parallel?

引用了此线程

function get1(id) {
    return new Promise((resolve, reject) => {
        const params = {
            FunctionName: 'myLambda', // the lambda function we are going to invoke
            InvocationType: 'RequestResponse',
            Payload: { id },
        };

        lambda.invoke(params, (err, data) => {
            if (err) {
                reject(new Error('error'));
            } else {
                const result = JSON.parse(data.Payload);
                resolve(result);
            }
        });
    }).catch(e => Promise.resolve({ error: 'Error has occurred.' }));
}

exports.getDetails = list => Promise.all(list.map(get1))
    .then((response) => {
        return result;
    }).catch((error) => {
        console.log('oops ', error);
    });

推荐答案

您可以算出已经开始但尚未完成的操作数:

You could count how many actions are started and haven't finished yet:

  let running = 0;

  // Inside of the promise:
  running++;
  lambda.invoke(params, (err, data) => {
    running--;
    console.log(`lambda.invoked finished, ${running} tasks still running`);
  });

如果invoke是同步的，则会得到:

If invoke is synchronous, you get:

  lambda.invoked finished, 0 tasks still running
  lambda.invoked finished, 0 tasks still running
  lambda.invoked finished, 0 tasks still running

如果它是异步的，则会得到:

If it is asynchronous you get:

  lambda.invoked finished, 2 tasks still running
  lambda.invoked finished, 1 tasks still running
  lambda.invoked finished, 0 tasks still running

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