// and then calls coroexit to remove the extra concurrency.
func corostart() {
	gp := getg()
	c := gp.coroarg
	gp.coroarg = nil

	defer coroexit(c)
	c.f(c)
}

// coroexit is like coroswitch but closes the coro
// and exits the current goroutine
func coroexit(c *coro) {
	gp := getg()
	gp.coroarg = c
	gp.coroexit = true
	mcall(coroswitch_m)
}

//go:linkname coroswitch

// Called to initialize a new m (including the bootstrap m).
// Called on the new thread, can not allocate memory.
func minit() {
	getg().m.procid = uint64(getthrid())
	minitSignals()
}

// Called from dropm to undo the effect of an minit.
//
//go:nosplit
func unminit() {
	unminitSignals()
	getg().m.procid = 0
}

// Called from exitm, but not from drop, to undo the effect of thread-owned

so their memory remains type stable. As a result, the runtime can
avoid write barriers in the depths of the scheduler.

`getg()` and `getg().m.curg`
----------------------------

To get the current user `g`, use `getg().m.curg`.

`getg()` alone returns the current `g`, but when executing on the
system or signal stacks, this will return the current M's "g0" or

//
// Ensure mayMoreStackPreempt can be called for all ABIs.
//
//go:nosplit
//go:linkname mayMoreStackPreempt
func mayMoreStackPreempt() {
	// Don't do anything on the g0 or gsignal stack.
	gp := getg()
	if gp == gp.m.g0 || gp == gp.m.gsignal {
		return
	}
	// Force a preemption, unless the stack is already poisoned.
	if gp.stackguard0 < stackPoisonMin {
		gp.stackguard0 = stackPreempt
	}
}

		// symbolizer.
		pcBuf[0] = logicalStackSentinel
		if getg() == gp {
			nstk += callers(skip+1, pcBuf[1:])
		} else if gp != nil {
			nstk += gcallers(gp, skip, pcBuf[1:])
		}
	} else {
		// Fast path: Unwind using frame pointers.
		pcBuf[0] = uintptr(skip)
		if getg() == gp {
			nstk += fpTracebackPCs(unsafe.Pointer(getfp()), pcBuf[1:])
		} else if gp != nil {
			// Three cases:

		minitSignalStack()
	}
	minitSignalMask()
	getg().m.procid = uint64(pthread_self())
}

// Called from dropm to undo the effect of an minit.
//
//go:nosplit
func unminit() {
	// iOS does not support alternate signal stack.
	// See minit.
	if !(GOOS == "ios" && GOARCH == "arm64") {
		unminitSignals()
	}
	getg().m.procid = 0
}

	"internal/goarch"
	"internal/stringslite"
	"unsafe"
)

// May run during STW, so write barriers are not allowed.
//
//go:nowritebarrierrec
func sighandler(_ureg *ureg, note *byte, gp *g) int {
	gsignal := getg()
	mp := gsignal.m

	var t sigTabT
	var docrash bool
	var sig int
	var flags int
	var level int32

	c := &sigctxt{_ureg}
	notestr := gostringnocopy(note)

		// Note: wasm can't tail call, so we can't get the original caller's pc.
		throw(msg)
	}
	// TODO: is this redundant? How could we be in malloc
	// but not in the runtime? runtime/internal/*, maybe?
	gp := getg()
	if gp != nil && gp.m != nil && gp.m.mallocing != 0 {
		throw(msg)
	}
}

// Same as above, but calling from the runtime is allowed.
//
// Using this function is necessary for any panic that may be

// anyhow for values on the stack. Just ignore msanread when running
// on the system stack. The other msan functions are fine.
//
//go:linkname msanread
//go:nosplit
func msanread(addr unsafe.Pointer, sz uintptr) {
	gp := getg()
	if gp == nil || gp.m == nil || gp == gp.m.g0 || gp == gp.m.gsignal {
		return
	}
	domsanread(addr, sz)
}

//go:noescape
func domsanread(addr unsafe.Pointer, sz uintptr)

//go:linkname msanwrite

		debug.SetGCPercent(ogcpercent)
	}
}

func debugCallWorker(ready chan<- *runtime.G, stop *uint32, done chan<- error) {
	runtime.LockOSThread()
	defer runtime.UnlockOSThread()

	ready <- runtime.Getg()

	x := 2
	debugCallWorker2(stop, &x)
	if x != 1 {
		done <- fmt.Errorf("want x = 2, got %d; register pointer not adjusted?", x)
	}
	close(done)
}