Std::cout << "Main function ends " << std::endl Sleep for 2 seconds, so that detached exits by then Sleep for 2 seconds because if main function exits, then other threads will Std::cout << "Failed to detach Thread : " << strerror(err) << std::endl Std::cout << "Thread Created with ID : " << threadId << std::endl Std::cout << "Thread creation failed : " << strerror(err) Int err = pthread_create(&threadId, NULL, &threadFunc, NULL) Create a thread that will funtion threadFunc() Std::cout << "Thread Function :: End" << std::endl Std::cout << "Thread Function :: Start" << std::endl Pthread_detach() will return non zero value in case of error. Pthread_join() will return non zero value in case of error.Ĭheck out the following example of Joinable Thread,Īlso, as detached thread automatically release the resources on exit, therefore there is no way to determine its return value of detached thread function. (void **), it will point to the return value of thread function i.e. Second parameter of pthread_join() is address of (void *) i.e.First parameter of pthread_join() is the ID of target thread.Pthread_join() is a blocking call, it will block the calling thread until the other thread ends. Int pthread_join(pthread_t thread, void **retval) A Thread can run in two modes i.e.īy default a thread runs in joinable mode. Joinable thread will not release any resource even after the end of thread function, until some other thread calls pthread_join() with its ID. It depends on which mode thread is running. When a thread exits ideally these resources should be reclaimed by process automatically. But that doesn’t happens always. You probably don't want that - make it static or put it outside the function definition (or malloc() it), but make sure it's not on the stack.With every thread some resources are associated like stack and thread local storage etc. * Mind you, the different sizes problem is weird - are you programming for an embedded device or something?
#Join and cancel pthread c code#
This code may work, but that's only because you misuse your pointers one way, then manage to misuse them in exactly the opposite way. They're very important, and can lead to subtle and hard-to-detect bugs (as well as your programs haemorrhaging segfaults) if misused. You should definitely find a tutorial on pointers and have a good study of it - go through all the exercises, make sure you understand all of it. You don't seem to have fully grasped the concepts of pointers or types. Your second problem is also the culmination of two problems - instead of declaring "ret" to be a "void *", you may as well be more type-safe and declare it an "int *", and then "int nm = (int*)ret " should become "int nm = *ret ".Īs a third point - I hope you can see that the number of things wrong in such a short piece of code should ring some alarm bells. You want the result to be stored at the address of y, so it should be "pthread_exit(&y)". In "pthread_exit((void *)y)", you're telling pthread_exit there's a return value at address 10 - I'm surprised it doesn't segfault*. Trust me, cutting and pasting the complete source when you post error messages helps.Įither way, missing includes is obviously not your problem. Also, posting the complete source (including #include directives) means that the warning messages you print will mean something - if your code were complete, you'd have errors at the definition of main() and your return statement that just don't match up - luckily it's quite simple code, and working out where the errors "really" are isn't much of a problem. Well, I thought maybe your warnings were all from not using #include if it's not there - but they'd probably be errors.
#Join and cancel pthread c mac#
The version of gcc is 4.2.1 and I'm on Mac OSX! The code at the first post is complete! Is only a test!