#include "spinlock.h"
void
-initlock(struct spinlock *lock, char *name)
+initlock(struct spinlock *lk, char *name)
{
- lock->name = name;
- lock->locked = 0;
- lock->cpu = 0xffffffff;
+ lk->name = name;
+ lk->locked = 0;
+ lk->cpu = 0xffffffff;
}
// Acquire the lock.
// Holding a lock for a long time may cause
// other CPUs to waste time spinning to acquire it.
void
-acquire(struct spinlock *lock)
+acquire(struct spinlock *lk)
{
pushcli();
- if(holding(lock))
+ if(holding(lk))
panic("acquire");
// The xchg is atomic.
// It also serializes, so that reads after acquire are not
- // reordered before it.
- while(xchg(&lock->locked, 1) == 1)
+ // reordered before it.
+ while(xchg(&lk->locked, 1) != 0)
;
// Record info about lock acquisition for debugging.
// The +10 is only so that we can tell the difference
// between forgetting to initialize lock->cpu
// and holding a lock on cpu 0.
- lock->cpu = cpu() + 10;
- getcallerpcs(&lock, lock->pcs);
+ lk->cpu = cpu() + 10;
+ getcallerpcs(&lk, lk->pcs);
}
// Release the lock.
void
-release(struct spinlock *lock)
+release(struct spinlock *lk)
{
- if(!holding(lock))
+ if(!holding(lk))
panic("release");
- lock->pcs[0] = 0;
- lock->cpu = 0xffffffff;
+ lk->pcs[0] = 0;
+ lk->cpu = 0xffffffff;
// The xchg serializes, so that reads before release are
// not reordered after it. The 1996 PentiumPro manual (Volume 3,
// after a store. So lock->locked = 0 would work here.
// The xchg being asm volatile ensures gcc emits it after
// the above assignments (and after the critical section).
- xchg(&lock->locked, 0);
+ xchg(&lk->locked, 0);
popcli();
}