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  • // 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.
    
    
    // +build aix darwin dragonfly freebsd linux netbsd openbsd solaris
    
    import (
    
    	"internal/oserror"
    
    	"internal/race"
    
    	darwin64Bit = runtime.GOOS == "darwin" && sizeofPtr == 8
    	netbsd32Bit = runtime.GOOS == "netbsd" && sizeofPtr == 4
    
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    func Syscall(trap, a1, a2, a3 uintptr) (r1, r2 uintptr, err Errno)
    func Syscall6(trap, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2 uintptr, err Errno)
    func RawSyscall(trap, a1, a2, a3 uintptr) (r1, r2 uintptr, err Errno)
    func RawSyscall6(trap, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2 uintptr, err Errno)
    
    // clen returns the index of the first NULL byte in n or len(n) if n contains no NULL byte.
    func clen(n []byte) int {
    	for i := 0; i < len(n); i++ {
    		if n[i] == 0 {
    			return i
    		}
    	}
    	return len(n)
    }
    
    
    // Mmap manager, for use by operating system-specific implementations.
    
    type mmapper struct {
    	sync.Mutex
    	active map[*byte][]byte // active mappings; key is last byte in mapping
    
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    	mmap   func(addr, length uintptr, prot, flags, fd int, offset int64) (uintptr, error)
    	munmap func(addr uintptr, length uintptr) error
    
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    func (m *mmapper) Mmap(fd int, offset int64, length int, prot int, flags int) (data []byte, err error) {
    
    	if length <= 0 {
    		return nil, EINVAL
    	}
    
    	// Map the requested memory.
    	addr, errno := m.mmap(0, uintptr(length), prot, flags, fd, offset)
    
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    	if errno != nil {
    
    		return nil, errno
    	}
    
    	// Slice memory layout
    	var sl = struct {
    		addr uintptr
    		len  int
    		cap  int
    	}{addr, length, length}
    
    
    	// Use unsafe to turn sl into a []byte.
    
    	b := *(*[]byte)(unsafe.Pointer(&sl))
    
    	// Register mapping in m and return it.
    	p := &b[cap(b)-1]
    	m.Lock()
    	defer m.Unlock()
    	m.active[p] = b
    
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    	return b, nil
    
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    func (m *mmapper) Munmap(data []byte) (err error) {
    
    	if len(data) == 0 || len(data) != cap(data) {
    		return EINVAL
    	}
    
    	// Find the base of the mapping.
    	p := &data[cap(data)-1]
    	m.Lock()
    	defer m.Unlock()
    	b := m.active[p]
    	if b == nil || &b[0] != &data[0] {
    		return EINVAL
    	}
    
    	// Unmap the memory and update m.
    
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    	if errno := m.munmap(uintptr(unsafe.Pointer(&b[0])), uintptr(len(b))); errno != nil {
    
    		return errno
    	}
    
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    	delete(m.active, p)
    
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    	return nil
    }
    
    // An Errno is an unsigned number describing an error condition.
    
    // It implements the error interface. The zero Errno is by convention
    
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    // a non-error, so code to convert from Errno to error should use:
    //	err = nil
    //	if errno != 0 {
    //		err = errno
    //	}
    
    //
    // Errno values can be tested against error values from the the os package
    // using errors.Is. For example:
    //
    //	_, _, err := syscall.Syscall(...)
    //	if errors.Is(err, os.ErrNotExist) ...
    
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    type Errno uintptr
    
    func (e Errno) Error() string {
    
    	if 0 <= int(e) && int(e) < len(errors) {
    
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    		s := errors[e]
    		if s != "" {
    			return s
    		}
    	}
    	return "errno " + itoa(int(e))
    }
    
    
    func (e Errno) Is(target error) bool {
    	switch target {
    	case oserror.ErrPermission:
    		return e == EACCES || e == EPERM
    	case oserror.ErrExist:
    		return e == EEXIST || e == ENOTEMPTY
    	case oserror.ErrNotExist:
    		return e == ENOENT
    	}
    	return false
    }
    
    
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    func (e Errno) Temporary() bool {
    
    	return e == EINTR || e == EMFILE || e.Timeout()
    
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    }
    
    func (e Errno) Timeout() bool {
    	return e == EAGAIN || e == EWOULDBLOCK || e == ETIMEDOUT
    
    // Do the interface allocations only once for common
    // Errno values.
    var (
    	errEAGAIN error = EAGAIN
    	errEINVAL error = EINVAL
    	errENOENT error = ENOENT
    )
    
    // errnoErr returns common boxed Errno values, to prevent
    // allocations at runtime.
    func errnoErr(e Errno) error {
    	switch e {
    	case 0:
    		return nil
    	case EAGAIN:
    		return errEAGAIN
    	case EINVAL:
    		return errEINVAL
    	case ENOENT:
    		return errENOENT
    	}
    	return e
    }
    
    
    // A Signal is a number describing a process signal.
    // It implements the os.Signal interface.
    type Signal int
    
    func (s Signal) Signal() {}
    
    func (s Signal) String() string {
    	if 0 <= s && int(s) < len(signals) {
    		str := signals[s]
    		if str != "" {
    			return str
    		}
    	}
    	return "signal " + itoa(int(s))
    }
    
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    func Read(fd int, p []byte) (n int, err error) {
    	n, err = read(fd, p)
    
    	if race.Enabled {
    
    			race.WriteRange(unsafe.Pointer(&p[0]), n)
    
    			race.Acquire(unsafe.Pointer(&ioSync))
    
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    	}
    
    	if msanenabled && n > 0 {
    		msanWrite(unsafe.Pointer(&p[0]), n)
    	}
    
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    	return
    }
    
    func Write(fd int, p []byte) (n int, err error) {
    
    	if race.Enabled {
    		race.ReleaseMerge(unsafe.Pointer(&ioSync))
    
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    	}
    
    	if race.Enabled && n > 0 {
    		race.ReadRange(unsafe.Pointer(&p[0]), n)
    
    	if msanenabled && n > 0 {
    		msanRead(unsafe.Pointer(&p[0]), n)
    	}
    
    // For testing: clients can set this flag to force
    // creation of IPv6 sockets to return EAFNOSUPPORT.
    var SocketDisableIPv6 bool
    
    type Sockaddr interface {
    
    	sockaddr() (ptr unsafe.Pointer, len _Socklen, err error) // lowercase; only we can define Sockaddrs
    
    }
    
    type SockaddrInet4 struct {
    	Port int
    	Addr [4]byte
    	raw  RawSockaddrInet4
    }
    
    type SockaddrInet6 struct {
    	Port   int
    	ZoneId uint32
    	Addr   [16]byte
    	raw    RawSockaddrInet6
    }
    
    type SockaddrUnix struct {
    	Name string
    	raw  RawSockaddrUnix
    }
    
    func Bind(fd int, sa Sockaddr) (err error) {
    	ptr, n, err := sa.sockaddr()
    	if err != nil {
    		return err
    	}
    	return bind(fd, ptr, n)
    }
    
    func Connect(fd int, sa Sockaddr) (err error) {
    	ptr, n, err := sa.sockaddr()
    	if err != nil {
    		return err
    	}
    	return connect(fd, ptr, n)
    }
    
    
    func Getpeername(fd int) (sa Sockaddr, err error) {
    	var rsa RawSockaddrAny
    	var len _Socklen = SizeofSockaddrAny
    	if err = getpeername(fd, &rsa, &len); err != nil {
    		return
    	}
    	return anyToSockaddr(&rsa)
    }
    
    
    func GetsockoptInt(fd, level, opt int) (value int, err error) {
    	var n int32
    	vallen := _Socklen(4)
    	err = getsockopt(fd, level, opt, unsafe.Pointer(&n), &vallen)
    	return int(n), err
    }
    
    
    func Recvfrom(fd int, p []byte, flags int) (n int, from Sockaddr, err error) {
    	var rsa RawSockaddrAny
    	var len _Socklen = SizeofSockaddrAny
    	if n, err = recvfrom(fd, p, flags, &rsa, &len); err != nil {
    		return
    	}
    	if rsa.Addr.Family != AF_UNSPEC {
    		from, err = anyToSockaddr(&rsa)
    	}
    	return
    }
    
    func Sendto(fd int, p []byte, flags int, to Sockaddr) (err error) {
    	ptr, n, err := to.sockaddr()
    	if err != nil {
    		return err
    	}
    	return sendto(fd, p, flags, ptr, n)
    }
    
    
    func SetsockoptByte(fd, level, opt int, value byte) (err error) {
    
    	return setsockopt(fd, level, opt, unsafe.Pointer(&value), 1)
    
    func SetsockoptInt(fd, level, opt int, value int) (err error) {
    	var n = int32(value)
    
    	return setsockopt(fd, level, opt, unsafe.Pointer(&n), 4)
    
    func SetsockoptInet4Addr(fd, level, opt int, value [4]byte) (err error) {
    
    	return setsockopt(fd, level, opt, unsafe.Pointer(&value[0]), 4)
    
    func SetsockoptIPMreq(fd, level, opt int, mreq *IPMreq) (err error) {
    
    	return setsockopt(fd, level, opt, unsafe.Pointer(mreq), SizeofIPMreq)
    
    func SetsockoptIPv6Mreq(fd, level, opt int, mreq *IPv6Mreq) (err error) {
    
    	return setsockopt(fd, level, opt, unsafe.Pointer(mreq), SizeofIPv6Mreq)
    
    }
    
    func SetsockoptICMPv6Filter(fd, level, opt int, filter *ICMPv6Filter) error {
    
    	return setsockopt(fd, level, opt, unsafe.Pointer(filter), SizeofICMPv6Filter)
    
    func SetsockoptLinger(fd, level, opt int, l *Linger) (err error) {
    
    	return setsockopt(fd, level, opt, unsafe.Pointer(l), SizeofLinger)
    
    func SetsockoptString(fd, level, opt int, s string) (err error) {
    
    	var p unsafe.Pointer
    	if len(s) > 0 {
    		p = unsafe.Pointer(&[]byte(s)[0])
    	}
    	return setsockopt(fd, level, opt, p, uintptr(len(s)))
    
    func SetsockoptTimeval(fd, level, opt int, tv *Timeval) (err error) {
    
    	return setsockopt(fd, level, opt, unsafe.Pointer(tv), unsafe.Sizeof(*tv))
    
    func Socket(domain, typ, proto int) (fd int, err error) {
    	if domain == AF_INET6 && SocketDisableIPv6 {
    		return -1, EAFNOSUPPORT
    	}
    	fd, err = socket(domain, typ, proto)
    	return
    }
    
    func Socketpair(domain, typ, proto int) (fd [2]int, err error) {
    	var fdx [2]int32
    	err = socketpair(domain, typ, proto, &fdx)
    	if err == nil {
    		fd[0] = int(fdx[0])
    		fd[1] = int(fdx[1])
    	}
    	return
    }
    
    
    func Sendfile(outfd int, infd int, offset *int64, count int) (written int, err error) {
    
    	if race.Enabled {
    		race.ReleaseMerge(unsafe.Pointer(&ioSync))
    
    	}
    	return sendfile(outfd, infd, offset, count)
    }
    
    
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    var ioSync int64