// Start tracing.
	if err := trace.Start(os.Stdout); err != nil {
		log.Fatalf("failed to start tracing: %v", err)
	}
	// Run GOMAXPROCS a bunch of times, up and down.
	for i := 1; i <= 16; i *= 2 {
		runtime.GOMAXPROCS(i)
		time.Sleep(1 * time.Millisecond)
	}
	for i := 16; i >= 1; i /= 2 {
		runtime.GOMAXPROCS(i)
		time.Sleep(1 * time.Millisecond)
	}
	// Stop tracing.
	trace.Stop()

	// checks that the runtime doesn't do anything terrible.

	// This requires GOMAXPROCS=1 from the beginning to reliably
	// start a goroutine on the main thread.
	if runtime.GOMAXPROCS(-1) != 1 {
		println("requires GOMAXPROCS=1")
		os.Exit(1)
	}

	ready := make(chan bool, 1)
	go func() {
		// Because GOMAXPROCS=1, this *should* be on the main
		// thread. Stay there.
		runtime.LockOSThread()

// blocked goroutines, LockOSThread, pipes, and GOMAXPROCS).

//go:build ignore

package main

import (
	"bytes"
	"io"
	"log"
	"net"
	"os"
	"runtime"
	"runtime/trace"
	"sync"
	"time"
)

func main() {
	defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(8))
	outerDone := make(chan bool)

	go func() {
		defer func() {
			outerDone <- true

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

// Tests a many interesting cases (network, syscalls, a little GC, busy goroutines,
// blocked goroutines, LockOSThread, pipes, and GOMAXPROCS).

//go:build ignore

package main

import (
	"log"
	"net"
	"os"
	"runtime"
	"runtime/trace"
	"sync"
	"time"
)

func main() {
	var wg sync.WaitGroup
	done := make(chan bool)

KUBE_INTEGRATION_TEST_MAX_CONCURRENCY=${KUBE_INTEGRATION_TEST_MAX_CONCURRENCY:-"-1"}
if [[ ${KUBE_INTEGRATION_TEST_MAX_CONCURRENCY} -gt 0 ]]; then
  GOMAXPROCS=${KUBE_INTEGRATION_TEST_MAX_CONCURRENCY}
  export GOMAXPROCS
  kube::log::status "Setting parallelism to ${GOMAXPROCS}"
fi

# Give integration tests longer to run by default.
KUBE_TIMEOUT=${KUBE_TIMEOUT:--timeout=600s}
LOG_LEVEL=${LOG_LEVEL:-2}

	if err != nil {
		log.Fatalf("failed to dial: %v", err)
	}
	c.Close()
	var data [1]byte
	wp.Write(data[:])
	<-pipeReadDone

	oldGoMaxProcs := runtime.GOMAXPROCS(0)
	runtime.GOMAXPROCS(oldGoMaxProcs + 1)

	trace.Stop()

	runtime.GOMAXPROCS(oldGoMaxProcs)

	"log"
	"os"
	"runtime"
	"runtime/trace"
	"sync"
)

func main() {
	if err := trace.Start(os.Stdout); err != nil {
		log.Fatalf("failed to start tracing: %v", err)
	}

	defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(8))
	c0 := make(chan int, 1)
	c1 := make(chan int, 1)
	c2 := make(chan int, 1)
	const procs = 2
	var done sync.WaitGroup
	done.Add(4 * procs)
	for p := 0; p < procs; p++ {
		const iters = 1e3

package runtime

import (
	"internal/runtime/atomic"
	"unsafe"
)

// GOMAXPROCS sets the maximum number of CPUs that can be executing
// simultaneously and returns the previous setting. It defaults to
// the value of [runtime.NumCPU]. If n < 1, it does not change the current setting.
// This call will go away when the scheduler improves.
func GOMAXPROCS(n int) int {
	if GOARCH == "wasm" && n > 1 {

	// 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.