ReentrantLock is a Java mutex class.
A 'reentrant lock' is a lock that can be re-acquired by the current owner without blocking or deadlock. Java provides an implementation.
Questions tagged [reentrantlock]
230 questions
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Understanding deadlock with a simple example
I am working on understanding deadlock basics so I came up with below code. I have two threads acquiring locks in opposite order but they're not deadlocking. When I run it I see all the printouts. What am I doing wrong?
public class DeadlockBasics…
flash
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Example demonstrating the use of ReadWriteLock
I am trying to understand the concept of ReadWriteLock and implemented the below simple example. From what I have understood, whenever a thread has a readlock, another thread can acquire the readlock. But for a thread with writelock, no other thread…
ghostrider
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ReentrantLock - Concurrent money transfer operation
While I was reading some concurrency code samples on the internet I found this one (money transfer operation between 2 bank accounts):
class Account {
double balance;
int id;
public Account(int id, double balance){
…
johnnydoamaral
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Bow/Bower example in java oracle tutorial with lock object
In the java docs example, the lock.unlock() method is used twice, once in impendingBow() method and bow() method. My question is, shouldn't lock.unlock() method in impendingBow() method do the trick, why use it again in bow() method? The code below…
tanwir
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how does locking a reentrant lock again helps when we already have the lock on it?
So , a reentrant lock increments the count by one if the current thread acquires the lock again. what i am unable to understand is why and how that helps or benefits us?
Karan
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Is this the right way to use ReentrantLock.isHeldByCurrentThread?
I need to exclude web access from a ReentrantLock lock, see webAccess() method below. I can not add any parameter to webAccess() api because in real world it is our framework api that I am not supposed to change. To exclude webAccess from the lock,…
Kai
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Producer Consumer using Reentrant lock not working
I am trying to implement consumer-producer using a ReentrantLock as given below:
class Producer implements Runnable {
private List data;
private ReentrantLock lock;
Producer(List data,ReentrantLock lock)
{
…
learner
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Handle multiple tryLock() calls with a thread
As a method of synchronizaton between threads, in Java we can use the ReentrantLock class. It has a method called tryLock() which allows the thread not to wait if it notices that a thread has not been acquired yet. As it returns a boolean value, it…
Le Sir Dog
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Dead lock occur when assign multiple conditions to lock
My program require to print backward from 10 to 1. Each number print from
one thread. It uses one lock with multiple condition objects. But the
program cause a dead lock when I run it. This is my program.
This class working fine
import…
vtc
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Renentrant tryLock() not locking in multi threaded enviroment
This is regarding tryLock() method in re entrant locks. I am running the below sample code. I understand that this code will run into a deadlock.
import java.util.concurrent.locks.ReentrantLock;
public class TestMain {
public static void…
ZerekSees
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How to take Re-entrant lock on String value?
I have a multi-threaded application and I want to use re-entrant lock on a String. For example if I use normal synchronization my code will look like.
I don't want two threads of same IPaddress to enter in my loadBalance() so I take lock on IP…
T-Bag
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ReentrantLock demo: signal & return value; => Unlocked?
I am trying to learn basic concepts of Java 8 Concurrent Programming and
can not understand the Unlock with return in a demo snippet here :…
fmatz
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Java locks: Hand over hand locking through list
I'm trying to understand the java.util.concurrent.locks library and wanted to implement two threads which run through a list, whereas the second thread should not overtake (take the lead) the first thread. Specifically, I wanted to implement…
f.k
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difference between lock/unlock vs wait/notify in the OS
Title says it all, using a ReentrantLock, whats the difference between the lock unlock and using the condition with wait notify?
I know wait/notify is used with a condition, and inside a loop, is only that the difference?
How does the OS threats…
José Moreira
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Java Lock Condition Wait and Notify: IllegalMonitorStateException
I am new to Java. I just read the "core java" book. I met a issue about 'Condition & Lock'.
I typed a piece of code from the book to the eclipse to do some practice.
When I run the code ,the line of "sufficientFund.wait();" throws an…
gfan
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