// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// Emulation of the Unix signal SIGSEGV.
//
// On iOS, Go tests and apps under development are run by lldb.
// The debugger uses a task-level exception handler to intercept signals.
// Despite having a 'handle' mechanism like gdb, lldb will not allow a
// SIGSEGV to pass to the running program. For Go, this means we cannot

	}
	cmd.Wait()
	os.Exit(0)
}

func deathSignalChild() {
	c := make(chan os.Signal, 1)
	signal.Notify(c, syscall.SIGUSR1)
	go func() {
		<-c
		fmt.Println("ok")
		os.Exit(0)
	}()
	fmt.Println("start")

	buf := make([]byte, 32)
	os.Stdin.Read(buf)

	// We expected to be signaled before stdin closed
	fmt.Println("not ok")
	os.Exit(1)

}

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 }

	log  *profBuf // profile events written here

	// extra holds extra stacks accumulated in addNonGo
	// corresponding to profiling signals arriving on
	// non-Go-created threads. Those stacks are written
	// to log the next time a normal Go thread gets the
	// signal handler.
	// Assuming the stacks are 2 words each (we don't get
	// a full traceback from those threads), plus one word

	return e == EINTR || e == EMFILE || e.Timeout()
}

func (e Errno) Timeout() bool {
	return e == EAGAIN || e == ETIMEDOUT
}

// A Signal is a number describing a process signal.
// It implements the [os.Signal] interface.
type Signal uint8

const (
	SIGNONE Signal = iota
	SIGHUP
	SIGINT
	SIGQUIT
	SIGILL
	SIGTRAP
	SIGABRT
	SIGBUS
	SIGFPE
	SIGKILL
	SIGUSR1
	SIGSEGV
	SIGUSR2

	MOVD	R1, R4

	// Store g on gsignal's stack, so if we receive a signal
	// during VDSO code we can find the g.
	// If we don't have a signal stack, we won't receive signal,
	// so don't bother saving g.
	// When using cgo, we already saved g on TLS, also don't save
	// g here.
	// Also don't save g if we are already on the signal stack.
	// We won't get a nested signal.
	MOVBZ	runtime·iscgo(SB), R22
	CMP	R22, $0
	BNE	nosaveg

		return -1
	}
	return int(w >> shift)
}

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

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

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

func parseGracePeriods(statements map[string]string) (map[evictionapi.Signal]time.Duration, error) {
	if len(statements) == 0 {
		return nil, nil
	}
	results := map[evictionapi.Signal]time.Duration{}
	for signal, val := range statements {
		signal := evictionapi.Signal(signal)
		if !validSignal(signal) {
			return nil, fmt.Errorf(unsupportedEvictionSignal, signal)
		}
		gracePeriod, err := time.ParseDuration(val)

		t.Logf("%s", out)
	}
	if err != nil {
		if err := err.(*exec.ExitError); err != nil && err.Sys().(syscall.WaitStatus).Signaled() {
			if !bytes.Contains(out, []byte("+++ killed by")) {
				// strace itself occasionally crashes.
				// Here, it exited with a signal, but
				// the strace log didn't report any
				// signal from the child process.
				t.Log(err)
				testenv.SkipFlaky(t, 63734)
			}
		}
		t.Fatal(err)
	}

	// 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
	//