import (
	"fmt"
	"reflect"
	"runtime"
	"strings"
	"testing"
)

func TestRandomScheduling(t *testing.T) {
	// Scheduler is most consistent with GOMAXPROCS=1.
	// Use that to make the test most likely to fail.
	defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(1))
	const N = 10
	out := make([][]int, N)
	for i := 0; i < N; i++ {
		c := make(chan int, N)
		for j := 0; j < N; j++ {
			go func(j int) {
				c <- j

[!fuzz] skip
[short] skip
env GOCACHE=$WORK/cache

# Warm up the build cache with GOMAXPROCS unrestricted.
go test -c -o $devnull

# For the fuzzing phase, we reduce GOMAXPROCS to avoid consuming too many
# resources during the test. Ideally this would just free up resources to run
# other parallel tests more quickly, but unfortunately it is actually necessary
# in some 32-bit environments to prevent the fuzzing engine from running out of

// 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

		}
	}
	cdone <- true
}

// Borrowed from rwmutex_test.go
func hammerRWMutex(t *testing.T, gomaxprocs, numReaders, numIterations int) {
	t.Run(fmt.Sprintf("%d-%d-%d", gomaxprocs, numReaders, numIterations), func(t *testing.T) {
		resource := "test"
		runtime.GOMAXPROCS(gomaxprocs)
		// Number of active readers + 10000 * number of active writers.
		var activity int32
		cdone := make(chan bool)

		clocked <- true
		<-cunlock
		m.RUnlock()
		cdone <- true
	}
}

// Borrowed from rwmutex_test.go
func doTestParallelReaders(numReaders, gomaxprocs int) {
	runtime.GOMAXPROCS(gomaxprocs)
	m := NewLRWMutex()

	clocked := make(chan bool)
	cunlock := make(chan bool)
	cdone := make(chan bool)
	for i := 0; i < numReaders; i++ {

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

package main

// issue 2337
// The program deadlocked.

import "runtime"

func main() {
	runtime.GOMAXPROCS(2)
	runtime.GC()
	runtime.GOMAXPROCS(1)

func TestDebugCallUnsafePoint(t *testing.T) {
	skipUnderDebugger(t)

	// This can deadlock if there aren't enough threads or if a GC
	// tries to interrupt an atomic loop (see issue #10958).
	defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(8))

	// InjectDebugCall cannot be executed while a GC is actively in
	// progress. Wait until the current GC is done, and turn it off.
	//
	// See #49370.
	runtime.GC()

// 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)

	"testing"
)

func TestGoroutineProfile(t *testing.T) {
	// GoroutineProfile used to use the wrong starting sp for
	// goroutines coming out of system calls, causing possible
	// crashes.
	defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(100))

	var stop uint32
	defer atomic.StoreUint32(&stop, 1) // in case of panic

	var wg sync.WaitGroup
	for i := 0; i < 4; i++ {
		wg.Add(1)
		go func() {
			for atomic.LoadUint32(&stop) == 0 {

	// 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.