}
		if n == 0 {
			return nn, io.ErrUnexpectedEOF
		}
	}
}

// Pwrite wraps the pwrite system call.
func (fd *FD) Pwrite(p []byte, off int64) (int, error) {
	// Call incref, not writeLock, because since pwrite specifies the
	// offset it is independent from other writes.
	// Similarly, using the poller doesn't make sense for pwrite.
	if err := fd.incref(); err != nil {
		return 0, err
	}
	defer fd.decref()

		return 0, nil
	}
	return fixCount(syscall.Write(f.fd, b))
}

// pwrite writes len(b) bytes to the File starting at byte offset off.
// It returns the number of bytes written and an error, if any.
// Since Plan 9 preserves message boundaries, never allow
// a zero-byte write.
func (f *File) pwrite(b []byte, off int64) (n int, err error) {
	if err := f.writeLock(); err != nil {
		return 0, err
	}

	return pread(fd, buf, n, -1)
}

//go:nosplit
func write1(fd uintptr, buf unsafe.Pointer, n int32) int32 {
	return pwrite(int32(fd), buf, n, -1)
}

var _badsignal = []byte("runtime: signal received on thread not created by Go.\n")

// This runs on a foreign stack, without an m or a g. No stack split.
//
//go:nosplit
func badsignal2() {
	pwrite(2, unsafe.Pointer(&_badsignal[0]), int32(len(_badsignal)), -1)

  // For the read-only case we only need that the last unknown write is already
  // tracked by the last `resource` write since we don't have dependencies to
  // any other read accesses.
  // Otherwise, we need that the last unknown read(s) and write are already
  // tracked by any read or write accesses of `resource`.
  bool is_tracked = read_only ?

//               |           |
//               v           |
//             Write         |
//               |           |
//               v           |
//           NextIteration --+
//
// we won't put (Read, Write) in the returned set.  This is fine if
// auto-clustering can only cluster the Read->Write edge, but it is a problem if
// it clusters the Write->NextIteration->Merge->Read edges instead.  So we rely

		}
	}
	if msan.Enabled && n > 0 {
		msan.Write(unsafe.Pointer(&p[0]), uintptr(n))
	}
	if asan.Enabled && n > 0 {
		asan.Write(unsafe.Pointer(&p[0]), uintptr(n))
	}
	return
}

func Pwrite(fd int, p []byte, offset int64) (n int, err error) {
	if race.Enabled {
		race.ReleaseMerge(unsafe.Pointer(&ioSync))
	}
	n, err = pwrite(fd, p, offset)
	if race.Enabled && n > 0 {

// each implementation can easily instantiate the test suite to verify
// that it conforms to the requirements, without having to write
// similar tests repeatedly.  Here's an example:

#if 0

// First, define a fixture class template.  It should be parameterized
// by a type.  Remember to derive it from testing::Test.
template <typename T>
class FooTest : public testing::Test {
  ...
};

		}
	}
	return n, nil
}

// Pwrite emulates the Unix pwrite system call.
func (fd *FD) Pwrite(buf []byte, off int64) (int, error) {
	if fd.kind == kindPipe {
		// Pwrite does not work with pipes
		return 0, syscall.ESPIPE
	}
	// Call incref, not writeLock, because since pwrite specifies the
	// offset it is independent from other writes.
	if err := fd.incref(); err != nil {
		return 0, err
	}

	l.bytes(b[:])
}

//go:nosplit
func (l *debugLogWriter) byte(x byte) {
	l.ensure(1)
	pos := l.write
	l.write++
	l.data.b[pos%uint64(len(l.data.b))] = x
}

//go:nosplit
func (l *debugLogWriter) bytes(x []byte) {
	l.ensure(uint64(len(x)))
	pos := l.write
	l.write += uint64(len(x))
	for len(x) > 0 {
		n := copy(l.data.b[pos%uint64(len(l.data.b)):], x)
		pos += uint64(n)
		x = x[n:]

// each implementation can easily instantiate the test suite to verify
// that it conforms to the requirements, without having to write
// similar tests repeatedly.  Here's an example:

#if 0

// First, define a fixture class template.  It should be parameterized
// by a type.  Remember to derive it from testing::Test.
template <typename T>
class FooTest : public testing::Test {
  ...
};