This sets the linking mode as described in cmd/cgo/doc.go.
	-linkshared
		Link against installed Go shared libraries (experimental).
	-memprofile file
		Write memory profile to file.
	-memprofilerate rate
		Set runtime.MemProfileRate to rate.
	-msan
		Link with C/C++ memory sanitizer support.
	-o file
		Write output to file (default a.out, or a.out.exe on Windows).
	-pluginpath path

		match		= flag.String("test.run", "", "regular expression to select tests to run")
		memProfile	= flag.String("test.memprofile", "", "write a memory profile to the named file after execution")
		memProfileRate	= flag.Int("test.memprofilerate", 0, "if >=0, sets runtime.MemProfileRate")
		cpuProfile	= flag.String("test.cpuprofile", "", "write a cpu profile to the named file during execution")

// Previously profile special records could have been processed prematurely
// (while the object is still live).

package main

import (
	"runtime"
	"time"
	"unsafe"
)

func main() {
	runtime.MemProfileRate = 1
	// Allocate 1M 4-byte objects and set a finalizer for every third object.
	// Assuming that tiny block size is 16, some objects get finalizers setup
	// only for middle bytes. The finalizer resurrects that object.

// run to run. To avoid flakes, this test performs multiple
// experiments and only complains if all of them consistently fail.
func main() {
	// Sample at 16K instead of default 512K to exercise sampling more heavily.
	runtime.MemProfileRate = 16 * 1024

	if err := testInterleavedAllocations(); err != nil {
		panic(err.Error())
	}
	if err := testSmallAllocations(); err != nil {
		panic(err.Error())
	}
}

		if seen[key] {
			continue
		}
		if seen != nil {
			seen[key] = true
		}

		// Update MemProfileRate directly here since it
		// is int, not int32, and should only be updated
		// if specified in GODEBUG.
		if seen == nil && key == "memprofilerate" {
			if n, ok := atoi(value); ok {
				MemProfileRate = n
			}
		} else {
			for _, v := range dbgvars {
				if v.name == key {

	of MADV_FREE. This is less efficient, but causes RSS numbers to drop
	more quickly.

	memprofilerate: setting memprofilerate=X will update the value of runtime.MemProfileRate.
	When set to 0 memory profiling is disabled.  Refer to the description of
	MemProfileRate for the default value.

	profstackdepth: profstackdepth=128 (the default) will set the maximum stack

		total.FreeBytes += r.FreeBytes
		total.FreeObjects += r.FreeObjects
	}

	// Technically the rate is MemProfileRate not 2*MemProfileRate,
	// but early versions of the C++ heap profiler reported 2*MemProfileRate,
	// so that's what pprof has come to expect.
	rate := 2 * runtime.MemProfileRate

	// pprof reads a profile with alloc == inuse as being a "2-column" profile

				"the improvements are 'locked in'.", got, tt.minMb)
		}
	})
}

// If this flag is present, it means "testing" was imported by code that is built by the binary
var denylistedFlags = []string{
	"--test.memprofilerate",
}

func runBinariesTest(t *testing.T, f func(t *testing.T, name string)) {
	t.Helper()
	if *releasedir == "" {
		t.Skip("release dir not set")
	}
	binariesToTest := strings.Split(*binaries, " ")

// to sample allocations on average every MemProfileRate bytes, but with a
// completely random distribution over the allocation timeline; this
// corresponds to a Poisson process with parameter MemProfileRate. In Poisson
// processes, the distance between two samples follows the exponential
// distribution (exp(MemProfileRate)), so the best return value is a random

	skip = flag.String("test.skip", "", "do not list or run tests matching `regexp`")
	memProfile = flag.String("test.memprofile", "", "write an allocation profile to `file`")
	memProfileRate = flag.Int("test.memprofilerate", 0, "set memory allocation profiling `rate` (see runtime.MemProfileRate)")
	cpuProfile = flag.String("test.cpuprofile", "", "write a cpu profile to `file`")