t.Skip("skipping during short test")
	}
	maxprocs := runtime.GOMAXPROCS(3)
	compl := make(chan bool, 2)
	go func() {
		for i := 0; i != 1000; i += 1 {
			runtime.GC()
		}
		compl <- true
	}()
	go func() {
		for i := 0; i != 1000; i += 1 {
			runtime.GOMAXPROCS(3)
		}
		compl <- true
	}()
	go perpetuumMobile()
	<-compl
	<-compl
	stop <- true
	runtime.GOMAXPROCS(maxprocs)
}

	// face of varying environments.
	debug.SetGCPercent(100)

	// Set GOMAXPROCS to 1 to minimize the amount of memory held in the page cache,
	// and to reduce the chance that the background scavenger gets scheduled.
	defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(1))

	// Allocate allocTotal bytes of memory in allocChunk byte chunks.

	// the indicated delay.
	//
	// Even if GOMAXPROCS=1, we expect the runtime to eventually schedule
	// the AfterFunc goroutine instead of the runnable channel goroutine.
	// However, in https://go.dev/issue/65178 this was observed to live-lock
	// on wasip1/wasm and js/wasm after <10000 runs.
	defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(1))

	var (
		wg   sync.WaitGroup
		stop atomic.Bool

func applyGCLoad(b *testing.B) func() {
	// We’ll apply load to the runtime with maxProcs-1 goroutines
	// and use one more to actually benchmark. It doesn't make sense
	// to try to run this test with only 1 P (that's what
	// BenchmarkReadMemStats is for).
	maxProcs := runtime.GOMAXPROCS(-1)
	if maxProcs == 1 {
		b.Skip("This benchmark can only be run with GOMAXPROCS > 1")
	}

	// Code to build a big tree with lots of pointers.

			fn: func(t *testing.T) {
				runtime.GC()
			},
		},
		{
			name: "runtime.GOMAXPROCS",
			fn: func(t *testing.T) {
				if runtime.GOARCH == "wasm" {
					t.Skip("GOMAXPROCS >1 not supported on wasm")
				}

				n := runtime.GOMAXPROCS(0)
				defer runtime.GOMAXPROCS(n)

				runtime.GOMAXPROCS(n + 1)
			},
		},
		{
			name: "runtime.GoroutineProfile",
			fn: func(t *testing.T) {

package runtime_test

import (
	"internal/testenv"
	"math"
	"runtime"
	"sync"
	"sync/atomic"
	"testing"
	"time"
)

func TestChan(t *testing.T) {
	defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(4))
	N := 200
	if testing.Short() {
		N = 20
	}
	for chanCap := 0; chanCap < N; chanCap++ {
		{
			// Ensure that receive from empty chan blocks.
			c := make(chan int, chanCap)
			recv1 := false

		return true
	}
	// Collect matching benchmarks and determine longest name.
	maxprocs := 1
	for _, procs := range cpuList {
		if procs > maxprocs {
			maxprocs = procs
		}
	}
	ctx := &benchContext{
		match:  newMatcher(matchString, *matchBenchmarks, "-test.bench", *skip),
		extLen: len(benchmarkName("", maxprocs)),
	}
	var bs []InternalBenchmark
	for _, Benchmark := range benchmarks {

	errFatal(err)

	// Wait for all to connect
	// Parallel writes per server.
	b.Run("bytes", func(b *testing.B) {
		for par := 1; par <= 32; par *= 2 {
			b.Run("par="+strconv.Itoa(par*runtime.GOMAXPROCS(0)), func(b *testing.B) {
				defer timeout(60 * time.Second)()
				ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
				defer cancel()
				b.ReportAllocs()
				b.SetBytes(int64(len(payload) * 2))

	// Cannot use t.Parallel - modifies global GOMAXPROCS.
	if testing.Short() {
		t.Skip("skipping in short mode")
	}
	defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(1))
	testVariousDeadlines(t)
}

// There is a very similar copy of this in net/timeout_test.go.
func TestVariousDeadlines4Proc(t *testing.T) {
	// Cannot use t.Parallel - modifies global GOMAXPROCS.
	if testing.Short() {

				break
			}
			gomaxprocs := int(m.Value.Uint64())
			if len(ps) > gomaxprocs {
				if flags&UtilPerProc != 0 {
					// End each P's series.
					for _, p := range ps[gomaxprocs:] {
						out[p.series] = addUtil(out[p.series], MutatorUtil{int64(ev.Time()), 0})
					}
				}
				ps = ps[:gomaxprocs]
			}
			for len(ps) < gomaxprocs {
				// Start new P's series.
				series := 0