//
// After a successful call to Start the [Cmd.Wait] method must be called in
// order to release associated system resources.
func (c *Cmd) Start() error {
	// Check for doubled Start calls before we defer failure cleanup. If the prior
	// call to Start succeeded, we don't want to spuriously close its pipes.
	if c.Process != nil {
		return errors.New("exec: already started")
	}

	started := false
	defer func() {

	"github.com/google/pprof/profile"
)

// fetchProfiles fetches and symbolizes the profiles specified by s.
// It will merge all the profiles it is able to retrieve, even if
// there are some failures. It will return an error if it is unable to
// fetch any profiles.
func fetchProfiles(s *source, o *plugin.Options) (*profile.Profile, error) {
	sources := make([]profileSource, 0, len(s.Sources))

					if err != nil {
						// If the timing didn't work out, it is possible for this Dial
						// to return an error (depending on the kernel's buffering behavior).
						// In https://go.dev/issue/65240 we saw failures with ECONNREFUSED
						// and ECONNRESET.
						//
						// What this test really cares about is the behavior of Accept, not
						// Dial, so just log the error and ignore it.
						t.Logf("DialContext: %v", err)

// which invokes b.Run in its own tests (see sub_test.go).
var hideStdoutForTesting = false

// Run benchmarks f as a subbenchmark with the given name. It reports
// whether there were any failures.
//
// A subbenchmark is like any other benchmark. A benchmark that calls Run at
// least once will not be measured itself and will be called once with N=1.
func (b *B) Run(name string, f func(b *B)) bool {

	// at least some of these OCONVNOPs (e.g., reinsert them after the
	// OADDR operation), but at least walkCompare needs to be fixed to
	// support that (see trybot failures on go.dev/cl/541715, PS1).
	if ir.IsAddressable(n) {
		if name, ok := ir.OuterValue(n).(*ir.Name); ok && name.Op() == ir.ONAME {
			if name.Class == ir.PAUTO && !name.Addrtaken() && ssa.CanSSA(name.Type()) {
				goto Copy

			// Trigger lots of synchronization and memory reads/writes to
			// increase the likelihood that the race described in #27660
			// results in corruption of ThreadSanitizer's internal state
			// and thus an assertion failure or segfault.
			i := 0
			for ctx.Err() == nil {
				j := rand.Intn(100)
				locks[j].Lock()
				ints[j]++
				locks[j].Unlock()
				// needed for gccgo, to avoid creation of an

	// Changes in how we account for non-file form data may cause the exact point
	// where we change from rejecting the form as too large to accepting it to vary,
	// but we should see both successes and failures.
	const failWhenMaxMemoryLessThan = 128
	for maxMemory := int64(0); maxMemory < failWhenMaxMemoryLessThan*2; maxMemory += 16 {
		b := strings.NewReader(testBody)
		r := NewReader(b, boundary)

			t.Skip("skipping gdb tests on AIX; see https://golang.org/issue/35710")
		}
	case "plan9":
		t.Skip("there is no gdb on Plan 9")
	}
}

func checkGdbVersion(t *testing.T) {
	// Issue 11214 reports various failures with older versions of gdb.
	out, err := exec.Command("gdb", "--version").CombinedOutput()
	if err != nil {
		t.Skipf("skipping: error executing gdb: %v", err)
	}
	re := regexp.MustCompile(`([0-9]+)\.([0-9]+)`)

// so that those files (in the runtime/library) can change without affecting
// this test.
//
// These choices can be reversed with -i (inlining on) and -r (repeats detected) which
// will also cause their own failures against the expected outputs.  Note that if the compiler
// and debugger were behaving properly, the inlined code and repeated lines would not appear,

		t.Fatalf("Drivers = %v, want sorted list with at least [invalid, test]", all)
	}
}

// hook to simulate connection failures
var hookOpenErr struct {
	sync.Mutex
	fn func() error
}

func setHookOpenErr(fn func() error) {
	hookOpenErr.Lock()
	defer hookOpenErr.Unlock()
	hookOpenErr.fn = fn
}