Since you seem to be asking a fairly general question about signals, I would advise you to avoid them as much as you possibly can, especially on Windows.

As for why, this long discussion thread includes a lot of historical detail on the personalities and politics behind early Windows development, especially signals and the Windows POSIX subsystem.

Update: to further clarify, signals should be avoided on Windows, where they are not a native IPC mechanism. Though there is no avoiding them on Unix (where they are native) you must take great care when writing C signal handlers to ensure they are async-signal-safe because they tend to crash and malfunction in strange ways if not (as noted here recently :). Disclaimer: though I've used signals in Unix C code, I've hardly used them in Perl. You might like to search for "signal" in this long technical node from the inimitable BrowserUk describing his experiences with signals on Windows, where he noted "their use in multi-threaded Perl code is very confused".