住房和城乡建设部网站干部学院,站长工具在线平台,浦东手机网站建设,京icp备号在线查询创建EventLoopGroup使用无参构造方法时#xff0c;发现会创建24个NioEventLoop#xff08;readonlyChildren.size24#xff09;,经查#xff0c;是取的java虚拟机的可用处理器数2倍。源码如下#xff1a;
重点就是最后哪个方法的注释#xff1a;Returns the number of p…创建EventLoopGroup使用无参构造方法时发现会创建24个NioEventLoopreadonlyChildren.size24,经查是取的java虚拟机的可用处理器数2倍。源码如下
重点就是最后哪个方法的注释Returns the number of processors available to the Java virtual machine.(返回Java虚拟机可用的处理器数。) /*** see MultithreadEventExecutorGroup#MultithreadEventExecutorGroup(int, Executor, Object...)*/protected MultithreadEventLoopGroup(int nThreads, Executor executor, Object... args) {//如果没指定线程数则取默认的DEFAULT_EVENT_LOOP_THREADS super(nThreads 0 ? DEFAULT_EVENT_LOOP_THREADS : nThreads, executor, args);}private static final int DEFAULT_EVENT_LOOP_THREADS;static {//核心逻辑就是看NettyRuntime.availableProcessors() * 2DEFAULT_EVENT_LOOP_THREADS Math.max(1, SystemPropertyUtil.getInt(io.netty.eventLoopThreads, NettyRuntime.availableProcessors() * 2));if (logger.isDebugEnabled()) {logger.debug(-Dio.netty.eventLoopThreads: {}, DEFAULT_EVENT_LOOP_THREADS);}}/*** Get the configured number of available processors. The default is {link Runtime#availableProcessors()}.* This can be overridden by setting the system property io.netty.availableProcessors or by invoking* {link #setAvailableProcessors(int)} before any calls to this method.** return the configured number of available processors*/SuppressForbidden(reason to obtain default number of available processors)synchronized int availableProcessors() {//如果availableProcessors 0还未设置过就取Runtime.getRuntime().availableProcessors()if (this.availableProcessors 0) {final int availableProcessors SystemPropertyUtil.getInt(io.netty.availableProcessors,Runtime.getRuntime().availableProcessors());setAvailableProcessors(availableProcessors);}return this.availableProcessors;}}/*** Returns the number of processors available to the Java virtual machine.** p This value may change during a particular invocation of the virtual* machine. Applications that are sensitive to the number of available* processors should therefore occasionally poll this property and adjust* their resource usage appropriately. /p** return the maximum number of processors available to the virtual* machine; never smaller than one* since 1.4*/public native int availableProcessors();
