多线程为多核处理器

本文介绍了多线程为多核处理器的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述 29岁程序员，3月因学历无情被辞！ 我有三星Galaxy S3，它使用了自家的Exynos 4四核处理​​器。所以，我要优化我的应用程序，它可以使用处理器的所有4个内核。I have Samsung Galaxy S3, which used its own Exynos 4 Quad processor.So I want to optimize my app, that it can use all 4 cores of processor.所以我做了一些测试： 在一个线程中运行任务。处理时间 - 8秒Run task in one thread. Processing time - 8 seconds.在四线程运行的任务。处理时间 - 还是8秒Run task in four threads. Processing time - still 8 sec. new Thread() { public void run() { // do 1/4 of task }}.start();new Thread() { public void run() { // do 1/4 of task }}.start();new Thread() { public void run() { // do 1/4 of task }}.start();new Thread() { public void run() { // do 1/4 of task }}.start(); 在ExecutorService的运行任务。和处理时间 - 还是8秒Run task in ExecutorService. And processing time - still 8 sec.ExecutorService threadPool = null;threadPool = Executors.newFixedThreadPool(4);threadPool.execute(new Runnable() { @Override public void run() { // do 1/4 of task }});threadPool.execute(new Runnable() { @Override public void run() { // do 1/4 of task }});threadPool.execute(new Runnable() { @Override public void run() { // do 1/4 of task }});threadPool.execute(new Runnable() { @Override public void run() { // do 1/4 of task }});看起来像同步完成所有的工作。为什么它不是并联？Looks like all work done synchronously. Why its not paralleling ?推荐答案您可以尝试用C或Java我的测试中，You can try my tests, in C or Java: http://bigflake.com/cpu-spinner.c.txt   http://bigflake.com/MultiCore.java.txthttp://bigflake.com/cpu-spinner.c.txt http://bigflake.com/MultiCore.java.txt当MultiCore.java运行在一台Nexus 4，我明白了：When MultiCore.java is run on a Nexus 4, I see:Thread 1 finished in 1516ms (1267234688)Thread 3 finished in 1494ms (1519485328)Thread 0 finished in 1530ms (51099776)Thread 2 finished in 1543ms (-1106614992)All threads finished in 1550ms 更新：它是有用的观看测试与systrace。作为回答了类似的一部分question我建立了一个网页，显示systrace输出此测试。你可以看到线程调度，并观看了另外两个内核旋转起来。Update:It's useful to watch the test with systrace. As part of answering a similar question I set up a page that shows the systrace output for this test. You can see how the threads are scheduled, and watch the other two cores spin up. 这篇关于多线程为多核处理器的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！ 上岸，阿里云！