Java multithreading – the life cycle of threads

The life cycle of a thread is divided into five stages: new, runnable, running, blocked and dead.

After the thread is started, with the CPU scheduling, the thread will switch between running and blocking.

New: after creating a thread with the new keyword, the thread will be in the new state;

Ready: after the thread object calls the start method, the thread is in a ready state. At this time, whether the thread can run depends on the scheduling of the JVM thread scheduler;

Run: after the thread obtains the CPU, it enters the running state;

Blocking: threads that do not die enter the blocking state after losing CPU;

Death: the execution of thread run () method is completed; The thread throws an uncapped exception or error; The thread actively calls the stop () method to end the current thread.

Thread from run to block:

Thread from blocking to ready state:

Thread state transition diagram:

About thread death: