// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

//go:build aix || darwin

package syscall

// forkExecPipe opens a pipe and non-atomically sets O_CLOEXEC on both file
// descriptors.
func forkExecPipe(p []int) error {
	err := Pipe(p)
	if err != nil {
		return err
	}
	_, err = fcntl(p[0], F_SETFD, FD_CLOEXEC)
	if err != nil {
		return err
	}

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

//go:build dragonfly || freebsd || linux || netbsd || openbsd || solaris

package syscall

import "sync"

// forkExecPipe atomically opens a pipe with O_CLOEXEC set on both file
// descriptors.
func forkExecPipe(p []int) error {
	return Pipe2(p, O_CLOEXEC)
}

var (
	// Guard the forking variable.
	forkingLock sync.Mutex

	}
	if sys.Setctty && sys.Ctty >= len(attr.Files) {
		return 0, errorspkg.New("Setctty set but Ctty not valid in child")
	}

	acquireForkLock()

	// Allocate child status pipe close on exec.
	if err = forkExecPipe(p[:]); err != nil {
		releaseForkLock()
		return 0, err
	}

	// Kick off child.
	pid, err1 = forkAndExecInChild(argv0p, argvp, envvp, chroot, dir, attr, sys, p[1])
	if err1 != 0 {
		Close(p[0])

	}
	nextfd++

	// Allocate another pipe for parent to child communication for
	// synchronizing writing of User ID/Group ID mappings.
	if sys.UidMappings != nil || sys.GidMappings != nil {
		if err := forkExecPipe(mapPipe[:]); err != nil {
			err1 = err.(Errno)
			return
		}
	}

	flags = sys.Cloneflags
	if sys.Cloneflags&CLONE_NEWUSER == 0 && sys.Unshareflags&CLONE_NEWUSER == 0 {
		flags |= CLONE_VFORK | CLONE_VM