// it is inspecting the given environment variables or files.
// Multiple goroutines may call these methods simultaneously.
type Interface interface {
	Getenv(key string)
	Stat(file string)
	Open(file string)
	Chdir(dir string)
}

// logger is the current logger Interface.
// We use an atomic.Value in case test startup
// is racing with goroutines started during init.
// That must not cause a race detector failure,

// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

//go:build ignore

// Compute Fibonacci numbers with two goroutines
// that pass integers back and forth.  No actual
// concurrency, just threads and synchronization
// and foreign code on multiple pthreads.

package main

import (
	big "."
	"runtime"
)

	}
	// Example log:
	//
	// ...] Observed a panic: test panic
	// goroutine 6 [running]:
	// command-line-arguments.logPanic(0x..., 0x...)
	// 	.../src/k8s.io/kubernetes/staging/src/k8s.io/apimachinery/pkg/util/runtime/runtime.go:69 +0x...
	lines := strings.Split(log, "\n")
	if len(lines) < 4 {
		t.Fatalf("panic log should have 1 line of message, 1 line per goroutine and 2 lines per function call")
	}

}

/* Before fix:

invalid m->locked = 2
fatal error: internal lockOSThread error

goroutine 2 [runnable]:
runtime.MHeap_Scavenger()
	/Users/rsc/g/go/src/pkg/runtime/mheap.c:438
runtime.goexit()
	/Users/rsc/g/go/src/pkg/runtime/proc.c:1313
created by runtime.main
	/Users/rsc/g/go/src/pkg/runtime/proc.c:165

goroutine 3 [runnable]:
main.func·002()
	/Users/rsc/g/go/test/fixedbugs/issue5963.go:22
created by main.init·1

//
// Random numbers are generated by a [Source], usually wrapped in a [Rand].
// Both types should be used by a single goroutine at a time: sharing among
// multiple goroutines requires some kind of synchronization.
//
// Top-level functions, such as [Float64] and [Int],
// are safe for concurrent use by multiple goroutines.
//
// This package's outputs might be easily predictable regardless of how it's

	return io.Copy(w, tcpConnWithoutWriteTo{TCPConn: c})
}

// Limit the number of concurrent cgo-using goroutines, because
// each will block an entire operating system thread. The usual culprit
// is resolving many DNS names in separate goroutines but the DNS
// server is not responding. Then the many lookups each use a different
// thread, and the system or the program runs out of threads.

//
// Random numbers are generated by a [Source], usually wrapped in a [Rand].
// Both types should be used by a single goroutine at a time: sharing among
// multiple goroutines requires some kind of synchronization.
//
// Top-level functions, such as [Float64] and [Int],
// are safe for concurrent use by multiple goroutines.
//
// This package's outputs might be easily predictable regardless of how it's

	chans := make([]chan bool, count)
	for i := range chans {
		chans[i] = make(chan bool)
		go crashDumpsAllThreadsLoop(i, chans[i])
	}

	// Wait for all the goroutines to start executing.
	for _, c := range chans {
		<-c
	}

	// Tell our parent that all the goroutines are executing.
	if _, err := os.NewFile(3, "pipe").WriteString("x"); err != nil {
		fmt.Fprintf(os.Stderr, "write to pipe failed: %v\n", err)
		os.Exit(2)
	}

		case <-ctx.Done():
			return r
		case v, ok := <-c:
			if !ok {
				return r
			}
			r = append(r, v)
		}
	}
}

// Merge merges two channels into a single channel.
// This will leave a goroutine running until either both channels are closed
// or the context is canceled, at which point the returned channel is closed.
func Merge[Elem any](ctx context.Context, c1, c2 <-chan Elem) <-chan Elem {
	r := make(chan Elem)

				//
				// If we're in per-proc mode, we don't
				// count dedicated workers because
				// they kick all of the goroutines off
				// that P, so don't directly
				// contribute to goroutine latency.
				if !(flags&UtilPerProc != 0 && l.Label == "GC (dedicated)") {
					bgMark[ev.Goroutine()] = true
					ps[ev.Proc()].gc++
				}
			}
		}

		if flags&UtilPerProc == 0 {