- * Actually, doing any sort of I/O from within an signal handler is
- * "unsafe". But we'll _try_ to clean up the screen and terminal
- * settings on the way out.
+ * Much of this is unsafe from a signal handler. But we'll _try_ to clean
+ * up the screen and terminal settings on the way out.
+ *
+ * There are at least the following problems:
+ * 1) Walking the SCREEN list is unsafe, since all list management
+ * is done without any signal blocking.
+ * 2) On systems which have REENTRANT turned on, set_term() uses
+ * _nc_lock_global() which could deadlock or misbehave in other ways.
+ * 3) endwin() calls all sorts of stuff, many of which use stdio or
+ * other library functions which are clearly unsafe.