 |
 | Home | Contact Us | FAQ | Search & Site Map | Link to Us |
 | Sign In | Join | Other 45 Sites in Network |
Java Forum / General / October 2007pausing a thread
Hi, I have a for loop: class TestObject { void runApp() { for (int i = 0 ; i < 4; i++ ) { // create a new thread and wait for execution to complete } } } Each iteration of the loop I need to create a new thread > class TestObject { > void runApp() { [quoted text clipped - 6 lines] > > Each iteration of the loop I need to create a new thread Call join() after starting the thread to wait for it. But why do you need to start a thread, if you're just going to wait for it to complete? /gordon -- > > class TestObject { > > void runApp() { [quoted text clipped - 15 lines] > > -- The thread has a simple task. It runs a timer which monitors a file on the File System for modifications. If modifications are made then the thread is said to be "complete" and we can close the thread by 'return;' within the run method. Then the next iteration can start and repeat the process for 'n' iterations. > The thread has a simple task. It runs a timer which monitors a file on > the File System for modifications. If modifications are made then the > thread is said to be "complete" and we can close the thread by > 'return;' within the run method. Then the next iteration can start and > repeat the process for 'n' iterations. I still don't see why you need a Thread for this: for (int i = 0; i < 4; i++){ long initMod = file.getLastModified(); try{ Thread.sleep(1000); } catch(Exception e){ break; } if (file.getLastModified() != initMod){ // whatever } else{ // whatever else } } Thread.sleep is static so you don't need to start a new instance of Thread for that. Regards, Lothar  SignatureLothar Kimmeringer E-Mail: spamfang@kimmeringer.de PGP-encrypted mails preferred (Key-ID: 0x8BC3CD81) Always remember: The answer is forty-two, there can only be wrong questions! On Oct 19, 9:33 am, Lothar Kimmeringer <news200...@kimmeringer.de> wrote: > > The thread has a simple task. It runs a timer which monitors a file on > > the File System for modifications. If modifications are made then the [quoted text clipped - 31 lines] > Always remember: The answer is forty-two, there can only be wrong > questions! Yes, but doesn't that mean the thread will wait a maximum of 1 second for the "task" to complete before going to the next iteration? What if the time needed to make the modifications can be dynamic? Could happen in 2 seconds...3 seconds later...or even 10 days later? Thanks for your reply. /sqad > Yes, but doesn't that mean the thread will wait a maximum of 1 > second for the "task" to complete before going to the next > iteration? What if the time needed to make the modifications can be > dynamic? Could happen in 2 seconds...3 seconds later...or even 10 > days later? The point is that you use threads when you need to perform some action concurrent to the caller, i.e. so that the caller can continue with other work while the thread runs. If your caller simply waits for the thread to finish, it could have performed that work itself; the thread wasn't necessary. That said, the caller can wait for the thread to finish by calling t.join(), where t is a reference to the running thread. If you simply want to delay for some time, then call Thread.sleep(), just like that, without starting a thread. /gordon -- > > Yes, but doesn't that mean the thread will wait a maximum of 1 > > second for the "task" to complete before going to the next [quoted text clipped - 18 lines] > > -- Ahh understood and solved within the caller thread itself. I'll bake in a worker/producer solution at a later time so I can run concurrent threads. Thanks for the clarification, guys. /sqad Sorry, accidently pressed enter before filling out the post. In each iteration, I need to create a new thread that executes, but the TestObject class should stop/wait for the execution of each iteration's thread and then go onto the next iteration. I passed a Thread.currentThread() as a reference into the Thread class, so it can say...parent_thread_reference.wait()...but TestObject still executes over all iterations and then runs the thread for each iteration, which is not what I want. :-( Does what I say make sense? Any ideas? /sqad Free MagazinesGet these publications absolutely FREE for up to 12 months. There are no hidden fees and no obligation. Simply choose a title, complete the application form and submit it. Read more ...
|
Reply to this Message
|
 Sign In
 Join
 My Latest Posts My Monitored Threads My Blog My Photo Gallery My Profile My Homepage Start New Thread Enable EMail Alerts Rate this Thread
|
©2008 Advenet LLC Privacy Policy - Terms of Use
This website includes both content owned or controlled by Advenet as well as content owned or controlled by third parties.