Attempting to macro-ize gallir's spinlock

spinlock-macro.h

// macro-ize gallir's spinlock code from:
// http://stackoverflow.com/questions/6704252/atomic-memcpy-suggestion/28286503#28286503

// third version, thanks to kragen for explains of expression/statement and do/while protective coding

#define SPINLOCK(lock) do { while ((lock) || ! __sync_bool_compare_and_swap(&(lock) , 0 , 1));} while (0)

#define SPINUNLOCK(lock) (lock) = 0;

// and the wrap-a-block version

#define SPINLOCKME(lock, statement_or_block) \
                                       do { \
                                       lock_p * _mylock = &(lock); \
                                       while (*_mylock) || ! __sync_bool_compare_and_swap(_mylock , 0 , 1)); \
                                       statement_or_block; \   
                                       *_mylock = 0; \
                                     } while(0)

// for reference, my second attempt: 

#define SPINLOCK(lock) while (lock || ! __sync_bool_compare_and_swap(&lock , 0 , 1));

#define SPINUNLOCK(lock) lock = 0;

//

// for reference, my first attempt: will probably not work because of whitespace in code, but first attempt at a macro ever.

#define SPINLOCKME(lock, code) { \
                                   while (lock || ! __sync_bool_compare_and_swap(&lock , 0 , 1)); \
                                   code; \
                                   lock = 0; \
                               }