Why do I see THROW in a C library?

Question

When I do: less /usr/include/stdio.h (which is only a C library - nothing to do with C++)

I see __THROW after quite a few function declarat

Answer 1

To answer your other question concerning "This function is a possible cancellation point and therefore not marked with __THROW": This deals with multi-threading. You can "cancel" a thread, but it won't actually "cancel" until it reaches a cancellation point. Some more info: http://www.kernel.org/doc/man-pages/online/pages/man3/pthread_cancel.3.html