{name: "gccheckmark", value: &debug.gccheckmark},
	{name: "gcpacertrace", value: &debug.gcpacertrace},
	{name: "gcshrinkstackoff", value: &debug.gcshrinkstackoff},
	{name: "gcstoptheworld", value: &debug.gcstoptheworld},
	{name: "gctrace", value: &debug.gctrace},
	{name: "harddecommit", value: &debug.harddecommit},
	{name: "inittrace", value: &debug.inittrace},
	{name: "invalidptr", value: &debug.invalidptr},

	gcshrinkstackoff: setting gcshrinkstackoff=1 disables moving goroutines
	onto smaller stacks. In this mode, a goroutine's stack can only grow.

	gcstoptheworld: setting gcstoptheworld=1 disables concurrent garbage collection,
	making every garbage collection a stop-the-world event. Setting gcstoptheworld=2
	also disables concurrent sweeping after the garbage collection finishes.

		semrelease(&work.startSema)
		return
	}

	// In gcstoptheworld debug mode, upgrade the mode accordingly.
	// We do this after re-checking the transition condition so
	// that multiple goroutines that detect the heap trigger don't
	// start multiple STW GCs.
	mode := gcBackgroundMode
	if debug.gcstoptheworld == 1 {
		mode = gcForceMode
	} else if debug.gcstoptheworld == 2 {
		mode = gcForceBlockMode
	}

					env:     []string{"GOEXPERIMENT=rangefunc"},
					pkg:     pkg,
				})
		}
	}

	// GODEBUG=gcstoptheworld=2 tests. We only run these in long-test
	// mode (with GO_TEST_SHORT=0) because this is just testing a
	// non-critical debug setting.
	if !t.compileOnly && !t.short {
		t.registerTest("GODEBUG=gcstoptheworld=2 archive/zip",
			&goTest{
				variant: "runtime:gcstoptheworld2",
				timeout: 300 * time.Second,

	} else {
		c.fractionalUtilizationGoal = 0
	}

	// In STW mode, we just want dedicated workers.
	if debug.gcstoptheworld > 0 {
		dedicatedMarkWorkersNeeded = int64(procs)
		c.fractionalUtilizationGoal = 0
	}

	// Clear per-P state
	for _, p := range allp {
		p.gcAssistTime = 0
		p.gcFractionalMarkTime = 0
	}

func DumpDebugLog() string {
	gp := getg()
	gp.writebuf = make([]byte, 0, 1<<20)
	printDebugLog()
	buf := gp.writebuf
	gp.writebuf = nil

	return string(buf)
}

func ResetDebugLog() {
	stw := stopTheWorld(stwForTestResetDebugLog)
	for l := allDloggers; l != nil; l = l.allLink {
		l.w.write = 0
		l.w.tick, l.w.nano = 0, 0
		l.w.r.begin, l.w.r.end = 0, 0
		l.w.r.tick, l.w.r.nano = 0, 0
	}
	startTheWorld(stw)

}

// Temporary variable for stopTheWorld, when it can't write to the stack.
//
// Protected by worldsema.
var stopTheWorldContext worldStop

// stopTheWorld stops all P's from executing goroutines, interrupting
// all goroutines at GC safe points and records reason as the reason
// for the stop. On return, only the current goroutine's P is running.
// stopTheWorld must not be called from a system stack and the caller

	setTraceback(level)
	traceback_env = traceback_cache
}

var ReadUnaligned32 = readUnaligned32
var ReadUnaligned64 = readUnaligned64

func CountPagesInUse() (pagesInUse, counted uintptr) {
	stw := stopTheWorld(stwForTestCountPagesInUse)

	pagesInUse = mheap_.pagesInUse.Load()

	for _, s := range mheap_.allspans {
		if s.state.get() == mSpanInUse {
			counted += s.npages
		}
	}

	startTheWorld(stw)

		// call).
		return int(gcount()), false
	}

	semacquire(&goroutineProfile.sema)

	ourg := getg()

	pcbuf := makeProfStack() // see saveg() for explanation
	stw := stopTheWorld(stwGoroutineProfile)
	// Using gcount while the world is stopped should give us a consistent view
	// of the number of live goroutines, minus the number of goroutines that are

package runtime

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

//go:linkname runtime_debug_WriteHeapDump runtime/debug.WriteHeapDump
func runtime_debug_WriteHeapDump(fd uintptr) {
	stw := stopTheWorld(stwWriteHeapDump)

	// Keep m on this G's stack instead of the system stack.
	// Both readmemstats_m and writeheapdump_m have pretty large
	// peak stack depths and we risk blowing the system stack.