// Set the stack bounds to match the current stack. If we don't
	// actually know how big the stack is, like we don't know how big any
	// scheduling stack is, but we assume there's at least 32 kB. If we
	// can get a more accurate stack bound from pthread, use that, provided
	// it actually contains SP..
	g0.stack.hi = sp + 1024
	g0.stack.lo = sp - 32*1024
	if !signal && _cgo_getstackbound != nil {

// alternate signal stack. If the alternate signal stack is not set
// for the thread (the normal case) then set the alternate signal
// stack to the gsignal stack. If the alternate signal stack is set
// for the thread (the case when a non-Go thread sets the alternate
// signal stack and then calls a Go function) then set the gsignal
// stack to the alternate signal stack. We also set the alternate

// license that can be found in the LICENSE file.

// Trace stack table and acquisition.

package runtime

import (
	"internal/abi"
	"internal/goarch"
	"unsafe"
)

const (
	// Maximum number of PCs in a single stack trace.
	// Since events contain only stack id rather than whole stack trace,
	// we can allow quite large values here.
	traceStackSize = 128

// [Handler.ServeHTTP].
func handlerRunning() bool {
	r := regexp.MustCompile(`net/http/cgi\.\(\*Handler\)\.ServeHTTP`)
	buf := make([]byte, 64<<10)
	for {
		n := runtime.Stack(buf, true)
		if n < len(buf) {
			return r.Match(buf[:n])
		}
		// Buffer wasn't large enough for a full goroutine dump.
		// Resize it and try again.
		buf = make([]byte, 2*len(buf))
	}
}

// stack.
//
// Synchronous safe-points are implemented by overloading the stack
// bound check in function prologues. To preempt a goroutine at the
// next synchronous safe-point, the runtime poisons the goroutine's
// stack bound to a value that will cause the next stack bound check
// to fail and enter the stack growth implementation, which will
// detect that it was actually a preemption and redirect to preemption
// handling.
//

			// endless recursion occurs if the cycle is not detected.
			//
			// If x and y were compared before, they must be equal
			// (if they were not, the recursion would have stopped);
			// search the ifacePair stack for the same pair.
			//
			// This is a quadratic algorithm, but in practice these stacks
			// are extremely short (bounded by the nesting depth of interface

Handler authors and others may wish to use [Value.Resolve] instead of calling LogValue directly.

# Wrapping output methods

The logger functions use reflection over the call stack to find the file name
and line number of the logging call within the application. This can produce
incorrect source information for functions that wrap slog. For instance, if you
define this function in file mylog.go:

		writeErrStr(failthreadcreate)
		exit(1)
	}

	// The caller passes in a suggested stack size,
	// from when we allocated the stack and thread ourselves,
	// without libpthread. Now that we're using libpthread,
	// we use the OS default stack size instead of the suggestion.
	// Find out that stack size for our own stack guard.
	if pthread_attr_getstacksize(&attr, &stacksize) != 0 {
		writeErrStr(failthreadcreate)
		exit(1)

func TestDecodeBounds(t *testing.T) {
	var buf [32]byte
	s := StdEncoding.EncodeToString(buf[:])
	defer func() {
		if err := recover(); err != nil {
			t.Fatalf("Decode panicked unexpectedly: %v\n%s", err, debug.Stack())
		}
	}()
	n, err := StdEncoding.Decode(buf[:], []byte(s))
	if n != len(buf) || err != nil {
		t.Fatalf("StdEncoding.Decode = %d, %v, want %d, nil", n, err, len(buf))
	}
}

			if !overflowed {
				t.Fail()
			}
		}

		for stack, traceSamples := range traceStacks {
			pprofSamples := pprofStacks[stack]
			delete(pprofStacks, stack)
			if traceSamples < pprofSamples {
				t.Logf("execution trace did not include all CPU profile samples for stack %q; %d in profile, %d in trace",
					stack, pprofSamples, traceSamples)
				if !overflowed {
					t.Fail()
				}
			}