Differences between Java y () and notfyall ()

 

Before policyall: rest in the rest area of the object

After policyall: wait in the queue to get the object lock.

 

Both y and notifyall wake up the threads in the rest area of an object. Notify can only wake up one thread, but which one is uncertain, while notifyall wakes up all the threads in the lounge of this object.

 

Notify is scheduled by the thread to randomly select a thread in the wait state for execution, and the thread is in the runnable state.

Notifyall is scheduled by the thread to wake up all the threads waiting on the lock. These threads are free to compete. One of the threads is in the runnable state and then executed.