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

// This file implements accept for platforms that provide a fast path for
// setting SetNonblock and CloseOnExec, but don't necessarily have accept4.
// The accept4(3c) function was added to Oracle Solaris in the Solaris 11.4.0
// release. Thus, on releases prior to 11.4, we fall back to the combination
// of accept(3c) and fcntl(2).

package poll

import (
	"internal/syscall/unix"

	iovecs := bytes2iovec(iovs)
	n, err = pwritev(fd, iovecs, off)
	return n, err
}

//sys	accept4(s int, rsa *RawSockaddrAny, addrlen *_Socklen, flags int) (fd int, err error) = libsocket.accept4

func Accept4(fd int, flags int) (nfd int, sa Sockaddr, err error) {
	var rsa RawSockaddrAny
	var len _Socklen = SizeofSockaddrAny
	nfd, err = accept4(fd, &rsa, &len, flags)
	if err != nil {
		return
	}
	if len > SizeofSockaddrAny {

		}
		return major > 11 || (major == 11 && minor >= 4)
	}
	return false
})

// SupportAccept4 tests whether accept4 system call is available.
var SupportAccept4 = sync.OnceValue(func() bool {
	for {
		// Test if the accept4() is available.
		_, _, err := syscall.Accept4(0, syscall.SOCK_NONBLOCK|syscall.SOCK_CLOEXEC)
		if err == syscall.EINTR {
			continue
		}
		return err != syscall.ENOSYS
	}
})

// This file implements accept for platforms that provide a fast path for
// setting SetNonblock and CloseOnExec.

//go:build dragonfly || freebsd || (linux && !arm) || netbsd || openbsd

package poll

import "syscall"

// Wrapper around the accept system call that marks the returned file
// descriptor as nonblocking and close-on-exec.
func accept(s int) (int, syscall.Sockaddr, string, error) {

	if wantSock != gotSock {
		t.Fatalf("SupportSockNonblockCloexec, got %t; want %t", gotSock, wantSock)
	}

	// Test that SupportAccept4 returns true if accept4 is available.
	for {
		_, _, err = syscall.Accept4(0, syscall.SOCK_NONBLOCK|syscall.SOCK_CLOEXEC)
		if err != syscall.EINTR {
			break
		}
	}
	wantAccept4 := err != syscall.ENOSYS
	gotAccept4 := unix.SupportAccept4()

//go:cgo_import_dynamic libc_preadv preadv "libc.so"
//go:cgo_import_dynamic libc_writev writev "libc.so"
//go:cgo_import_dynamic libc_pwritev pwritev "libc.so"
//go:cgo_import_dynamic libc_accept4 accept4 "libsocket.so"

//go:linkname procreadv libc_readv
//go:linkname procpreadv libc_preadv
//go:linkname procwritev libc_writev
//go:linkname procpwritev libc_pwritev
//go:linkname procaccept4 libc_accept4

var (

	if err == nil {
		p[0] = int(pp[0])
		p[1] = int(pp[1])
	}
	return err
}

//sys	accept4(fd int, rsa *RawSockaddrAny, addrlen *_Socklen, flags int) (nfd int, err error)

func Accept4(fd, flags int) (nfd int, sa Sockaddr, err error) {
	var rsa RawSockaddrAny
	var len _Socklen = SizeofSockaddrAny
	nfd, err = accept4(fd, &rsa, &len, flags)
	if err != nil {
		return
	}
	if len > SizeofSockaddrAny {

	return setsockopt(fd, level, opt, unsafe.Pointer(mreq), unsafe.Sizeof(*mreq))
}

func Accept4(fd, flags int) (nfd int, sa Sockaddr, err error) {
	var rsa RawSockaddrAny
	var len _Socklen = SizeofSockaddrAny
	nfd, err = accept4(fd, &rsa, &len, flags)
	if err != nil {
		return
	}
	if len > SizeofSockaddrAny {
		panic("RawSockaddrAny too small")
	}

func pwrite(fd int, p []byte, offset int64) (n int, err error) {
	return extpwrite(fd, p, 0, offset)
}

func Accept4(fd, flags int) (nfd int, sa Sockaddr, err error) {
	var rsa RawSockaddrAny
	var len _Socklen = SizeofSockaddrAny
	nfd, err = accept4(fd, &rsa, &len, flags)
	if err != nil {
		return
	}
	if len > SizeofSockaddrAny {
		panic("RawSockaddrAny too small")
	}

func pwrite(fd int, p []byte, offset int64) (n int, err error) {
	return extpwrite(fd, p, 0, offset)
}

func Accept4(fd, flags int) (nfd int, sa Sockaddr, err error) {
	var rsa RawSockaddrAny
	var len _Socklen = SizeofSockaddrAny
	nfd, err = accept4(fd, &rsa, &len, flags)
	if err != nil {
		return
	}
	if len > SizeofSockaddrAny {
		panic("RawSockaddrAny too small")
	}