When using cgo, Go must not assume that it owns all details of the
process. In particular it needs to coordinate with C in the use of
threads and thread-local storage. The runtime package declares a few
variables:

	var (
		iscgo             bool
		_cgo_init         unsafe.Pointer
		_cgo_thread_start unsafe.Pointer
	)

Any package using cgo imports "runtime/cgo", which provides

	check(t, "NewBuffer", &buf, testString)
}

func TestNewBufferString(t *testing.T) {
	buf := NewBufferString(testString)
	check(t, "NewBufferString", buf, testString)
}

// Empty buf through repeated reads into fub.
// The initial contents of buf corresponds to the string s.
func empty(t *testing.T, testname string, buf *Buffer, s string, fub []byte) {
	check(t, testname+" (empty 1)", buf, s)

	for {

*p += i
</pre>

<p>
If <code>i</code> and <code>*p</code> start equal to 2,
the original code does <code>*p = 3</code>,
so a racing thread can read only 2 or 3 from <code>*p</code>.
The rewritten code does <code>*p = 1</code> and then <code>*p = 3</code>,
allowing a racing thread to read 1 as well.
</p>

<p>
Note that all these optimizations are permitted in C/C++ compilers:

pkg syscall (windows-386), type ProcessEntry32 struct, ProcessID uint32
pkg syscall (windows-386), type ProcessEntry32 struct, Size uint32
pkg syscall (windows-386), type ProcessEntry32 struct, Threads uint32
pkg syscall (windows-386), type ProcessEntry32 struct, Usage uint32
pkg syscall (windows-amd64), const TH32CS_INHERIT = 2147483648
pkg syscall (windows-amd64), const TH32CS_INHERIT ideal-int

	}
	return data
}

// ReadByte reads and returns the next byte from the buffer.
// If no byte is available, it returns error io.EOF.
func (b *Buffer) ReadByte() (byte, error) {
	if b.empty() {
		// Buffer is empty, reset to recover space.
		b.Reset()
		return 0, io.EOF
	}
	c := b.buf[b.off]
	b.off++
	b.lastRead = opRead
	return c, nil
}

// ReadRune reads and returns the next UTF-8-encoded

	PAXRecords map[string]string

	// Format specifies the format of the tar header.
	//
	// This is set by Reader.Next as a best-effort guess at the format.
	// Since the Reader liberally reads some non-compliant files,
	// it is possible for this to be FormatUnknown.
	//
	// If the format is unspecified when Writer.WriteHeader is called,
	// then it uses the first format (in the order of USTAR, PAX, GNU)

	creatorFAT    = 0
	creatorUnix   = 3
	creatorNTFS   = 11
	creatorVFAT   = 14
	creatorMacOSX = 19

	// Version numbers.
	zipVersion20 = 20 // 2.0
	zipVersion45 = 45 // 4.5 (reads and writes zip64 archives)

	// Limits for non zip64 files.
	uint16max = (1 << 16) - 1
	uint32max = (1 << 32) - 1

	// Extra header IDs.
	//
	// IDs 0..31 are reserved for official use by PKWARE.

// immediately stops the scanning.
//
// Otherwise, the [Scanner] advances the input. If the token is not nil,
// the [Scanner] returns it to the user. If the token is nil, the
// Scanner reads more data and continues scanning; if there is no more
// data--if atEOF was true--the [Scanner] returns. If the data does not
// yet hold a complete token, for instance if it has no newline while

	if b.uint32() != 1 { // total number of disks
		return -1, nil // the file is not a valid zip64-file
	}
	return int64(p), nil
}

// readDirectory64End reads the zip64 directory end and updates the
// directory end with the zip64 directory end values.
func readDirectory64End(r io.ReaderAt, offset int64, d *directoryEnd) (err error) {
	buf := make([]byte, directory64EndLen)

<li>
<code>LOCAL</code> = 128
<br>
This symbol is local to the dynamic shared object.
</li>
<li>
<code>TLSBSS</code> = 256
<br>
(For <code>DATA</code> and <code>GLOBL</code> items.)
Put this data in thread local storage.
</li>
<li>
<code>NOFRAME</code> = 512
<br>
(For <code>TEXT</code> items.)
Do not insert instructions to allocate a stack frame and save/restore the return