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

package runtime

import _ "unsafe" // for go:linkname

//go:linkname setMaxStack runtime/debug.setMaxStack
func setMaxStack(in int) (out int) {
	out = int(maxstacksize)
	maxstacksize = uintptr(in)
	return out
}

//go:linkname setPanicOnFault runtime/debug.setPanicOnFault
func setPanicOnFault(new bool) (old bool) {

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

package debug

import (
	"time"
)

// Implemented in package runtime.
func readGCStats(*[]time.Duration)
func freeOSMemory()
func setMaxStack(int) int
func setGCPercent(int32) int32
func setPanicOnFault(bool) bool
func setMaxThreads(int) int

package main

import "runtime/debug"

type Foo struct {
	A [1 << 20]byte
	B string
}

func run(c chan bool) {
	f := new(Foo)
	*f = Foo{B: "hello"}
	c <- true
}

func main() {
	debug.SetMaxStack(1 << 16)
	c := make(chan bool)
	go run(c)
	<-c

// of the value provided to SetMaxStack.
//
// SetMaxStack is useful mainly for limiting the damage done by
// goroutines that enter an infinite recursion. It only limits future
// stack growth.
func SetMaxStack(bytes int) int {
	return setMaxStack(bytes)
}

// SetMaxThreads sets the maximum number of operating system
// threads that the Go program can use. If it attempts to use more than

		}
	}

	go F()
	go F()
	runtime.Goexit()
}

func StackOverflow() {
	var f func() byte
	f = func() byte {
		var buf [64 << 10]byte
		return buf[0] + f()
	}
	debug.SetMaxStack(1474560)
	f()
}

func ThreadExhaustion() {
	debug.SetMaxThreads(10)
	c := make(chan int)
	for i := 0; i < 100; i++ {
		go func() {
			runtime.LockOSThread()
			c <- 0
			select {}
		}()
		<-c

	}
}

func TestMaxStackSize(t *testing.T) {
	// This test must not run in parallel with other tests as debug.SetMaxStack
	// affects all goroutines.
	n := debug.SetMaxStack(1 << 16)
	defer debug.SetMaxStack(n)

	var wg sync.WaitGroup
	defer wg.Wait()

	b := make([]byte, 1<<20)
	for level := HuffmanOnly; level <= BestCompression; level++ {

		}
	}
}

func TestUNC(t *testing.T) {
	// Test that this doesn't go into an infinite recursion.
	// See golang.org/issue/15879.
	defer debug.SetMaxStack(debug.SetMaxStack(1e6))
	filepath.Glob(`\\?\c:\*`)
}

func testWalkMklink(t *testing.T, linktype string) {
	output, _ := exec.Command("cmd", "/c", "mklink", "/?").Output()

	if goarch.PtrSize == 8 {
		maxstacksize = 1000000000
	} else {
		maxstacksize = 250000000
	}

	// An upper limit for max stack size. Used to avoid random crashes
	// after calling SetMaxStack and trying to allocate a stack that is too big,
	// since stackalloc works with 32-bit sizes.
	maxstackceiling = 2 * maxstacksize

	// Allow newproc to start new Ms.
	mainStarted = true

	if haveSysmon {

		{"Module.Version", Field, 12},
		{"ParseBuildInfo", Func, 18},
		{"PrintStack", Func, 0},
		{"ReadBuildInfo", Func, 12},
		{"ReadGCStats", Func, 1},
		{"SetGCPercent", Func, 1},
		{"SetMaxStack", Func, 2},
		{"SetMaxThreads", Func, 2},
		{"SetMemoryLimit", Func, 19},
		{"SetPanicOnFault", Func, 3},
		{"SetTraceback", Func, 6},
		{"Stack", Func, 0},
		{"WriteHeapDump", Func, 3},
	},

pkg reflect, method (Value) SetCap(int)
pkg reflect, method (Value) Slice3(int, int, int) Value
pkg runtime, type MemStats struct, GCSys uint64
pkg runtime, type MemStats struct, OtherSys uint64
pkg runtime/debug, func SetMaxStack(int) int
pkg runtime/debug, func SetMaxThreads(int) int
pkg sort, func Stable(Interface)
pkg strings, func IndexByte(string, uint8) int
pkg sync/atomic, func SwapInt32(*int32, int32) int32