notify - w3toppers.com

who and when notify the thread.wait() when thread.join() is called?

As for jdk7 for linux, you can get the answer from the source code of openjdk. /jdk7/hotspot/src/os/linux/vm/os_linux.cpp int ret = pthread_create(&tid, &attr, (void* (*)(void*)) java_start, thread); static void *java_start(Thread *thread) { … thread->run(); return 0; } and when start thread in java, the thread will be instanceof JavaThread. /jdk7/hotspot/src/share/vm/runtime/thread.cpp void JavaThread::run() { … thread_main_inner(); } … Read more

Java Delay/Wait

Thread.sleep(1000); // do nothing for 1000 miliseconds (1 second)

MySQL listen notify equivalent

Ok, so what I found is that you can make UDF functions in mysql that can do anything but need to be written in C/C++. They can be then called from triggers on updates in database and notify your application when update happened. I saw that there are some security concerns. I did not use … Read more

Concept behind putting wait(),notify() methods in Object class [duplicate]

I am just having hard time to understand concept behind putting wait() in object class For this questions sake consider as if wait() and notifyAll() are in thread class In the Java language, you wait() on a particular instance of an Object – a monitor assigned to that object to be precise. If you want … Read more

Difference between Synchronized block with wait/notify and without them?

Using synchronized makes a method / block accessible by only on thread at a time. So, yes, it’s thread-safe. The two concepts are combined, not mutually-exclusive. When you use wait() you need to own the monitor on that object. So you need to have synchronized(..) on it before that. Using .wait() makes the current thread … Read more

How can the wait() and notify() methods be called on Objects that are not threads?

Locking is about protecting shared data. The lock is on the data structure being protected. The threads are the things accessing the data structure. The locks are on the data structure object in order to keep the threads from accessing the data structure in an unsafe way. Any object can be used as an intrinsic … Read more

running 3 threads in sequence java

Convert those IF statements to WHILE statements to get the desired behavior: if (notifyAllExample.status != 2){ notifyAllExample.wait(); } to while (notifyAllExample.status != 2){ notifyAllExample.wait(); } This will ensure that if a thread is notified, it won’t go out of the while loop until the status value is what it expects. Also, mark status as volatile … Read more

Why are wait() and notify() declared in Java’s Object class?

Because, you wait on a given Object (or specifically, its monitor) to use this functionality. I think you may be mistaken on how these methods work. They’re not simply at a Thread-granularity level, i.e. it is not a case of just calling wait() and being woken up by the next call to notify(). Rather, you … Read more

Java executors: how to be notified, without blocking, when a task completes?

Define a callback interface to receive whatever parameters you want to pass along in the completion notification. Then invoke it at the end of the task. You could even write a general wrapper for Runnable tasks, and submit these to ExecutorService. Or, see below for a mechanism built into Java 8. class CallbackTask implements Runnable … Read more

A simple scenario using wait() and notify() in java

The wait() and notify() methods are designed to provide a mechanism to allow a thread to block until a specific condition is met. For this I assume you’re wanting to write a blocking queue implementation, where you have some fixed size backing-store of elements. The first thing you have to do is to identify the … Read more