Synchronous signals are the result of an event that occurs inside a process and are delivered synchronously with respect to that event. For example, if a floating-point calculation results in an overflow, then a SIGFPE (floating-point exception signal) is delivered to the process immediately following the instruction that resulted in the overflow.
The default behavior of DCE Threads in DCE Version 1.0.2 when a synchronous terminating signal occurs is to dump core; that is, to not handle the signal. This differs from the behavior prior to DCE Version 1.0.2, in which such a signal would be turned into an exception and propagated out to whatever process was the original owner of the thread (namely the client, even though the exception might have occurred in the server). Therefore, if an application using DCE Threads wants to handle such signals, it must now set up a signal handler to do so by calling sigaction( ). Note that the new DCE Threads behavior is in fact similar to the default behavior of most UNIX programs.
Synchronous, terminating signals represent an error that has occurred in the currently executing thread.