#include "lsl_protos.h"


#define RW_LOCK_BIAS        TUNELOCK

/** Example implementation of linux rw lock along with 2 thread test
 *  driver... */

typedef struct rwlock {
	int lock;
} rwlock_t;


void lock_init(rwlock_t *lock) {
  lock->lock=RW_LOCK_BIAS;
}

int add(int * ptr, int val) {
  return lsl_add_32(ptr, val);
} 

int sub(int * ptr, int val) {
  return lsl_add_32(ptr, -val);
} 

int write_trylock(rwlock_t *rw) {
	int priorvalue=sub(&rw->lock, RW_LOCK_BIAS);

	int flag=priorvalue != RW_LOCK_BIAS;

	if (!flag) {
		add(&rw->lock, RW_LOCK_BIAS);
	}

	return flag;
}


void write_unlock(rwlock_t *rw) {
	add(&rw->lock, RW_LOCK_BIAS);
}

void foo(rwlock_t *mylock) {
	int flag=write_trylock(mylock);
	if (flag) {
		write_unlock(mylock);
	}
}

void bar(rwlock_t *mylock) {
	for(int i=0;i<PROBLEMSIZE;i++)
		foo(mylock);
}