A lock allows only one thread to enter the part that’s locked and the lock is not shared with any other processes. A mutex is the same as a lock but it can be system wide (shared by multiple processes). A semaphore does the same as a mutex but allows x number of threads to enter, this … Read more
In pthread_exit, ret is an input parameter. You are simply passing the address of a variable to the function. In pthread_join, ret is an output parameter. You get back a value from the function. Such value can, for example, be set to NULL. Long explanation: In pthread_join, you get back the address passed to pthread_exit by the finished thread. If you pass just a plain … Read more
A race condition occurs when two or more threads can access shared data and they try to change it at the same time. Because the thread scheduling algorithm can swap between threads at any time, you don’t know the order in which the threads will attempt to access the shared data. Therefore, the result of … Read more
When I am having a big heated discussion at work, I use a rubber chicken which I keep in my desk for just such occasions. The person holding the chicken is the only person who is allowed to talk. If you don’t hold the chicken you cannot speak. You can only indicate that you want … Read more