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public enum State { /** * Thread state for a thread which has not yet started. */ NEW, /** * Thread state for a runnable thread. A thread in the runnable * state is executing in the Java virtual machine but it may * be waiting for other resources from the operating system ...

Future usage In a multithreaded scenario, the runnable interface is generally implemented, the run method is overridden, and the return value is of void type. Therefore, the return result of the thread is not required in this case.   If you need the return result of the thread, you need to use the callable interface instead.   The usa ...

1. Thread Foundation This part is in the header file < thread > Main contents: std::thread t1(func, para); std::thread t2(&A::func, &Aobj, para); t1.join(); t1.detech(); t1.joinable(); 1.1 creating threads Basic mode: std::thread obj(func), func is an adjustable object, which can be: functionFunction object &nd ...

Pessimistic lock / optimistic lock: Pessimistic: do not allow other threads to intervene during operation. synchronized,lock Optimistic: other threads can intervene. Reference version number mechanism, CAS 1. Eight lock phenomenon - lock static state / lock method 1.0 standard access thread, print Email first and then SMS: class Phone{ p ...

IO multiplexing: The IO multiplexing model is based on the demultiplexing function select provided by the kernel. Using the select function can avoid the problem of polling and waiting in the synchronous non blocking IO model. select This function is used to monitor the change of file descriptor - read / write or exception Parameters ...

How to check whether there are Java thread deadlocks? Two methods are described below. I Jconsole Jconsole is a graphical interface tool provided by JDK. Using jconsole, a tool provided by JDK, you can open it by opening cmd and then entering jconsole. Connect to the process you want to view. Open the threads tab and click &quot ...

2.1. How threads are created The first method: directly use the Thread class, use anonymous inner classes or inheritance, and override the run method [no return value, no exception can be thrown] Merging threads and tasks @Slf4j public class ThreadDemo { public static void main(String[] args) { // How to use inheritance: inst ...

Concurrency / high concurrency tomcat default 150 concurrent connection (socket) RT: corresponding time QPS: throughput Hardware cpu, memory, disk, network Software Maximize the use of hardware resources Number of threads, JVM memory size, network communication mechanism (BIO, NIO, AIO), disk IO How to increase the number of concu ...

1, Principle analysis 1. Thread dependency This article explains that in multithreaded functions, there are dependencies between threads and shared data. Thread ABCD. A notifies B after completion, B notifies C after completion, C notifies d after completion, and a after completion. This cycle continues. A—>B—>C—& ...

Thread synchronization Basics In concurrent scenarios, sometimes we don't just want to protect data. We also want to synchronize some operations between multiple threads, such as waiting for a condition to be true or executing some operations when an event occurs. The C + + standard library provides condition variables and futures; Concurrency ...