• Post Reply Bookmark Topic Watch Topic
  • New Topic
programming forums Java Mobile Certification Databases Caching Books Engineering Micro Controllers OS Languages Paradigms IDEs Build Tools Frameworks Application Servers Open Source This Site Careers Other all forums
this forum made possible by our volunteer staff, including ...
Marshals:
  • Campbell Ritchie
  • Liutauras Vilda
  • Tim Cooke
  • Jeanne Boyarsky
  • Bear Bibeault
Sheriffs:
  • Knute Snortum
  • paul wheaton
  • Devaka Cooray
Saloon Keepers:
  • Tim Moores
  • Stephan van Hulst
  • Ron McLeod
  • Piet Souris
  • Ganesh Patekar
Bartenders:
  • Tim Holloway
  • Carey Brown
  • salvin francis

Thread wait() and notify()

 
Greenhorn
Posts: 1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Hello everyone,

I would just like to ask if the following code example in the Sierra Bates SCJP Reviewer below is correct. Is it possible for b.wait() in line 9 to wait forever if the notify() action in line 24 comes first?


1. class ThreadA {
2. public static void main(String [] args) {
3. ThreadB b = new ThreadB();
4. b.start();
5.
6. synchronized(b) {
7. try {
8. System.out.println("Waiting for b to complete...");
9. b.wait();
10. } catch (InterruptedException e) {}
11. System.out.println("Total is: " + b.total);
12. }
13. }
14. }
15.
16. class ThreadB extends Thread {
17. int total;
18.
19. public void run( ) {
20. synchronized(this) {
21. for(int i=0;i<100;i++) {
22. total += i;
23. }
24. notify( );
25. }
26. }
27. }


Thanks in advance.

 
Ranch Hand
Posts: 129
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Yes.

After line no:9, the main thread will wait(In Runnable state) until line no:24 executes or until the run method completes.

The Logic would be Main thread is waiting for threadB to complete the total and in Main thread you are displaying it.

 
Ranch Hand
Posts: 44
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
To Ayusarap:
I dont think so. In my mind, your code`s result is dynamic. Bug I am not sure about it. Can anyone explain it in detail. Thanks a lot.
 
Ranch Hand
Posts: 433
Eclipse IDE Firefox Browser Java
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
try this in between line 4 and 6 of your code :


Most probably(99.99999%) this will clarify Kathy and Bert..!!
 
Well behaved women rarely make history - Eleanor Roosevelt. tiny ad:
Enterprise-grade Excel API for Java
https://products.aspose.com/cells/java
  • Post Reply Bookmark Topic Watch Topic
  • New Topic
Boost this thread!