Threads Exit

A thread can arrange for functions to be called when the thread exits. These functions are known as thread cleanup handlers. More than one cleanup handler can be registered for each thread. Handlers are pushed onto a stack, which means they are executed in the reverse order from which they were added.

When a thread is canceled or terminates by calling pthread_exit(), all registered cleanup handlers are popped and executed in the reverse order in which they were pushed onto the stack.