// with its controlling terminal shall cause the process group
	// to be sent a SIGTTOU signal. If the calling thread is
	// blocking SIGTTOU signals or the process is ignoring SIGTTOU
	// signals, the process shall be allowed to perform the
	// operation, and no signal is sent."
	//  -https://pubs.opengroup.org/onlinepubs/9699919799/functions/tcsetpgrp.html
	//

		// than it does for an attempt to access a valid but unmapped address.
		// OS X 10.9.2 mishandles the malformed address case, making it look like
		// a user-generated signal (like someone ran kill -SEGV ourpid).
		// We pass user-generated signals to os/signal, or else ignore them.
		// Doing that here - and returning to the faulting code - results in an
		// infinite loop. It appears the best we can do is rewrite what the kernel

			} else if ws, ok := ee.Sys().(syscall.WaitStatus); !ok {
				t.Errorf("unexpected wait status type %T: %v", ee.Sys(), ee.Sys())
			} else if ws.Signaled() && ws.Signal() == syscall.SIGPIPE {
				if sig || dest > 2 {
					t.Errorf("unexpected SIGPIPE signal for descriptor %d sig %t", dest, sig)
				}
			} else {
				t.Errorf("unexpected exit status %v for descriptor %d sig %t", err, dest, sig)
			}
		}
	}

	/*
	The libc function(s) we call here must form a no-op and include at least one
	call that triggers TSAN to process pending asynchronous signals.

	sleep(0) would be fine, but it's not portable C (so it would need more header
	guards).
	free(NULL) has a fast-path special case in TSAN, so it doesn't
	trigger signal delivery.
	free(malloc(0)) would work (triggering the interceptors in malloc), but
	it also runs a bunch of user-supplied malloc hooks.

	SIGPOLL   = Signal(0x1d)
	SIGPROF   = Signal(0x1b)
	SIGPWR    = Signal(0x1e)
	SIGQUIT   = Signal(0x3)
	SIGSEGV   = Signal(0xb)
	SIGSTKFLT = Signal(0x10)
	SIGSTOP   = Signal(0x13)
	SIGSYS    = Signal(0x1f)
	SIGTERM   = Signal(0xf)
	SIGTRAP   = Signal(0x5)
	SIGTSTP   = Signal(0x14)
	SIGTTIN   = Signal(0x15)
	SIGTTOU   = Signal(0x16)
	SIGUNUSED = Signal(0x1f)
	SIGURG    = Signal(0x17)

			// When apiserver is shutting down, signal clients to retry
			// There is a good chance the client hit a different server, so a tight retry is good for client responsiveness.
			waitGroupWriteRetryAfterToResponse(w)
			return
		}

		// attach ServerShutdownSignal to the watch request so that the
		// watch handler loop can return as soon as the server signals
		// that it is shutting down.

	SIGPIPE   = Signal(0xd)
	SIGPROF   = Signal(0x1b)
	SIGQUIT   = Signal(0x3)
	SIGSEGV   = Signal(0xb)
	SIGSTOP   = Signal(0x11)
	SIGSYS    = Signal(0xc)
	SIGTERM   = Signal(0xf)
	SIGTRAP   = Signal(0x5)
	SIGTSTP   = Signal(0x12)
	SIGTTIN   = Signal(0x15)
	SIGTTOU   = Signal(0x16)
	SIGURG    = Signal(0x10)
	SIGUSR1   = Signal(0x1e)
	SIGUSR2   = Signal(0x1f)
	SIGVTALRM = Signal(0x1a)

	SIGIO      = Signal(0x16)
	SIGIOT     = Signal(0x6)
	SIGJVM1    = Signal(0x27)
	SIGJVM2    = Signal(0x28)
	SIGKILL    = Signal(0x9)
	SIGLOST    = Signal(0x25)
	SIGLWP     = Signal(0x21)
	SIGPIPE    = Signal(0xd)
	SIGPOLL    = Signal(0x16)
	SIGPROF    = Signal(0x1d)
	SIGPWR     = Signal(0x13)
	SIGQUIT    = Signal(0x3)
	SIGSEGV    = Signal(0xb)
	SIGSTOP    = Signal(0x17)
	SIGSYS     = Signal(0xc)

	MOVV	8(R3), R5	// nsec

	MOVV	R23, R3	// restore SP
	// Restore vdsoPC, vdsoSP
	// We don't worry about being signaled between the two stores.
	// If we are not in a signal handler, we'll restore vdsoSP to 0,
	// and no one will care about vdsoPC. If we are in a signal handler,
	// we cannot receive another signal.
	MOVV	16(R3), R25
	MOVV	R25, m_vdsoSP(R24)
	MOVV	8(R3), R25
	MOVV	R25, m_vdsoPC(R24)

	MOVV	R7, sec+0(FP)

}

func (w WaitStatus) Signaled() bool { return w&mask != stopped && w&mask != 0 }

func (w WaitStatus) Signal() Signal {
	sig := Signal(w & mask)
	if sig == stopped || sig == 0 {
		return -1
	}
	return sig
}

func (w WaitStatus) CoreDump() bool { return w.Signaled() && w&core != 0 }

func (w WaitStatus) Stopped() bool { return w&mask == stopped && Signal(w>>shift) != SIGSTOP }