_spinlock
void __libc_spinlock_stub(struct _spinlock *);
void __libc_spinunlock_stub(struct _spinlock *);
struct _spinlock;
extern struct _spinlock __stdio_thread_lock __hidden;
typedef struct _spinlock spinlock_t;
#define _SPINLOCK(_lck) _spinlock(_lck)
void _spinlock(spinlock_t *);
STATIC_LIB_REQUIRE(_spinlock);
struct _spinlock;
void __thr_spinunlock(struct _spinlock *lck);
void __thr_spinlock(struct _spinlock *lck);