pkg syscall (linux-amd64-cgo), type Flock_t struct, Pad_cgo_0 [4]uint8
pkg syscall (linux-amd64-cgo), type Flock_t struct, Pad_cgo_1 [4]uint8
pkg syscall (linux-amd64-cgo), type Flock_t struct, Pid int32
pkg syscall (linux-amd64-cgo), type Flock_t struct, Start int64
pkg syscall (linux-amd64-cgo), type Flock_t struct, Type int16
pkg syscall (linux-amd64-cgo), type Flock_t struct, Whence int16

	    and ends at the end of the innermost containing block.</li>

	<li>The scope of a type identifier declared inside a function
	    begins at the identifier in the TypeSpec
	    and ends at the end of the innermost containing block.</li>
</ol>

<p>
An identifier declared in a block may be redeclared in an inner block.
While the identifier of the inner declaration is in scope, it denotes

	// callback(x) calls goCallback(x)
	callbackMutex.Lock()
	callbackToken++
	i := callbackToken
	callbackFuncs[i] = f
	callbackMutex.Unlock()

	// Pass the address of i because the C function was written to
	// take a pointer.  We could pass an int if we felt like
	// rewriting the C code.
	C.callback(unsafe.Pointer(&i))

	callbackMutex.Lock()
	delete(callbackFuncs, i)
	callbackMutex.Unlock()
}