spinlock.c

#include "debug.h"
#include <clod/thread.h>
#include "yield.h"
 
void clod_spinlock_lock(clod_spinlock *spinlock) {
    clod_spinlock lock = 0;
    while (!clod_atomic_cas(spinlock, &lock, 1)) {
        #if CLOD_DEBUG_THREAD
        if (lock != 0 && lock != 1) {
            debug(CLOD_DEBUG_THREAD, "called clod_spinlock_lock on an invalid value.");
        }
        #endif
 
        for (int i = 0; i < 500; i++) {
            clod_pause();
            lock = 0;
            if (clod_atomic_cas(spinlock, &lock, 1))
                return;
        }
 
        clod_yield();
        lock = 0;
    }
}
 
void clod_spinlock_unlock(clod_spinlock *spinlock) {
    #if CLOD_DEBUG_THREAD
    clod_spinlock expected = 1;
    if (!clod_atomic_cas(spinlock, &expected, 0)) {
        debug(CLOD_DEBUG_THREAD, "called clod_spinlock_unlock on an unlocked spinlock.");
    }
    #else
    clod_atomic_store(spinlock, 0);
    #endif
}