Rejigger spinlock.c

52e99f8a · Silas Boyd-Wickizer · b0ecf098 · 52e99f8a
--- a/spinlock.c
+++ b/spinlock.c
@@ -8,6 +8,58 @@
 #include "spinlock.h"
 #include "mtrace.h"

+static inline void
+locking(struct spinlock *lk)
+{
+#if SPINLOCK_DEBUG
+  if(holding(lk)) {
+    cprintf("%p\n", __builtin_return_address(0));
+    panic("acquire");
+  }
+#endif
+
+  mtlock(lk);
+}
+
+static inline void
+locked(struct spinlock *lk)
+{
+  mtacquired(lk);
+  
+#if SPINLOCK_DEBUG
+  // Record info about lock acquisition for debugging.
+  lk->cpu = mycpu();
+  getcallerpcs(&lk, lk->pcs, NELEM(lk->pcs));
+#endif
+}
+
+static inline void
+releasing(struct spinlock *lk)
+{
+#if SPINLOCK_DEBUG
+  if(!holding(lk)) {
+    cprintf("lock: %s\n", lk->name);
+    panic("release");
+  }
+#endif
+
+  mtunlock(lk);
+
+#if SPINLOCK_DEBUG
+  lk->pcs[0] = 0;
+  lk->cpu = 0;
+#endif
+}
+
+// Check whether this cpu is holding the lock.
+#if SPINLOCK_DEBUG
+int
+holding(struct spinlock *lock)
+{
+  return lock->locked && lock->cpu == mycpu();
+}
+#endif
+
 void
 initlock(struct spinlock *lk, const char *name)
 {
@@ -21,27 +73,13 @@ initlock(struct spinlock *lk, const char *name)
 int
 tryacquire(struct spinlock *lk)
 {
-  pushcli(); // disable interrupts to avoid deadlock.
-
-#if SPINLOCK_DEBUG
-  if(holding(lk)) {
-    cprintf("%p\n", __builtin_return_address(0));
-    panic("acquire");
-  }
-#endif
-
-  mtlock(lk);
+  pushcli();
+  locking(lk);
  if (xchg32(&lk->locked, 1) != 0) {
      popcli();
      return 0;
  }
-  mtacquired(lk);
-
-#if SPINLOCK_DEBUG
-  // Record info about lock acquisition for debugging.
-  lk->cpu = mycpu();
-  getcallerpcs(&lk, lk->pcs, NELEM(lk->pcs));
-#endif
+  locked(lk);
  return 1;
 }

@@ -52,47 +90,21 @@ tryacquire(struct spinlock *lk)
 void
 acquire(struct spinlock *lk)
 {
-  pushcli(); // disable interrupts to avoid deadlock.
-
-#if SPINLOCK_DEBUG
-  if(holding(lk)) {
-    cprintf("%p\n", __builtin_return_address(0));
-    panic("acquire");
-  }
-#endif
-
-  mtlock(lk);
+  pushcli();
+  locking(lk);
  // The xchg is atomic.
  // It also serializes, so that reads after acquire are not
  // reordered before it.
  while(xchg32(&lk->locked, 1) != 0)
    ;
-  mtacquired(lk);
-
-#if SPINLOCK_DEBUG
-  // Record info about lock acquisition for debugging.
-  lk->cpu = mycpu();
-  getcallerpcs(&lk, lk->pcs, NELEM(lk->pcs));
-#endif
+  locked(lk);
 }

 // Release the lock.
 void
 release(struct spinlock *lk)
 {
-#if SPINLOCK_DEBUG
-  if(!holding(lk)) {
-    cprintf("lock: %s\n", lk->name);
-    panic("release");
-  }
-#endif
-
-  mtunlock(lk);
-
-#if SPINLOCK_DEBUG
-  lk->pcs[0] = 0;
-  lk->cpu = 0;
-#endif
+  releasing(lk);

  // The xchg serializes, so that reads before release are
  // not reordered after it.  The 1996 PentiumPro manual (Volume 3,
@@ -107,12 +119,3 @@ release(struct spinlock *lk)

  popcli();
 }
-
-// Check whether this cpu is holding the lock.
-#if SPINLOCK_DEBUG
-int
-holding(struct spinlock *lock)
-{
-    return lock->locked && lock->cpu == mycpu();
-}
-#endif