Using Exceptions in a Multithreaded Environment

The current exception-handling implementation is safe for multithreading--exceptions in one thread do not interfere with exceptions in other threads. However, you cannot use exceptions to communicate across threads; an exception thrown from one thread cannot be caught in another.

Each thread can set its own terminate() or unexpected() function. Calling set_terminate() or set_unexpected() in one thread affects only the exceptions in that thread. The default function for terminate() is abort() for the main thread, and thr_exit() for other threads (see "Specifying Runtime Errors").

Thread cancellation (pthread_cancel(3T)) results in the destruction of automatic (local nonstatic) objects on the stack. When a thread is cancelled, the execution of local destructors is interleaved with the execution of cleanup routines that the user has registered with pthread_cleanup_push(). The local objects for functions called after a particular cleanup routine is registered are destroyed before that routine is executed.