- {
- sig_atomic_t received[NSIG];
- int sig;
-
- for (sig = 0; sig < NSIG; sig++)
- if ((to_unblock >> sig) & 1)
- {
- if (signal (sig, old_handlers[sig]) != blocked_handler)
- /* The application changed a signal handler while the signal
- was blocked. We don't support this. */
- abort ();
- received[sig] = pending_array[sig];
- blocked_set &= ~(1U << sig);
- pending_array[sig] = 0;
- }
- else
- received[sig] = 0;
-
- for (sig = 0; sig < NSIG; sig++)
- if (received[sig])
- {
- #if HAVE_RAISE
- raise (sig);
- #else
- kill (getpid (), sig);
- #endif
- }
- }
+ {
+ sig_atomic_t received[NSIG];
+ int sig;
+
+ for (sig = 0; sig < NSIG; sig++)
+ if ((to_unblock >> sig) & 1)
+ {
+ if (signal (sig, old_handlers[sig]) != blocked_handler)
+ /* The application changed a signal handler while the signal
+ was blocked, bypassing our rpl_signal replacement.
+ We don't support this. */
+ abort ();
+ received[sig] = pending_array[sig];
+ blocked_set &= ~(1U << sig);
+ pending_array[sig] = 0;
+ }
+ else
+ received[sig] = 0;
+
+ for (sig = 0; sig < NSIG; sig++)
+ if (received[sig])
+ raise (sig);
+ }
+ }
+ return 0;
+}
+
+/* Install the handler FUNC for signal SIG, and return the previous
+ handler. */
+handler_t
+rpl_signal (int sig, handler_t handler)
+{
+ /* We must provide a wrapper, so that a user can query what handler
+ they installed even if that signal is currently blocked. */
+ if (sig >= 0 && sig < NSIG && sig != SIGKILL && sig != SIGSTOP
+ && handler != SIG_ERR)
+ {
+ #ifdef SIGABRT_COMPAT
+ if (sig == SIGABRT_COMPAT)
+ sig = SIGABRT;
+ #endif
+
+ if (blocked_set & (1U << sig))
+ {
+ /* POSIX states that sigprocmask and signal are both
+ async-signal-safe. This is not true of our
+ implementation - there is a slight data race where an
+ asynchronous interrupt on signal A can occur after we
+ install blocked_handler but before we have updated
+ old_handlers for signal B, such that handler A can see
+ stale information if it calls signal(B). Oh well -
+ signal handlers really shouldn't try to manipulate the
+ installed handlers of unrelated signals. */
+ handler_t result = old_handlers[sig];
+ old_handlers[sig] = handler;
+ return result;
+ }
+ else
+ return signal (sig, handler);
+ }
+ else
+ {
+ errno = EINVAL;
+ return SIG_ERR;
+ }
+}
+
+#if GNULIB_defined_SIGPIPE
+/* Raise the signal SIGPIPE. */
+int
+_gl_raise_SIGPIPE (void)
+{
+ if (blocked_set & (1U << SIGPIPE))
+ pending_array[SIGPIPE] = 1;
+ else
+ {
+ handler_t handler = SIGPIPE_handler;
+ if (handler == SIG_DFL)
+ exit (128 + SIGPIPE);
+ else if (handler != SIG_IGN)
+ (*handler) (SIGPIPE);