Notes/Spinlocks.txt

   1 SHORTLOCK()
   2         cli; lock cmpxchg
   3 SHORTREL()
   4         lock and ; sti
   5
   6
   7 LONGLOCK()
   8         mov eax, 1
   9         lock cmpxchg lock.lock, eax
  10         if(eax) {
  11                 SHORTLOCK(lock.listLock)
  12                 // add to list (linked list, 4 static entries)
  13                 SHORTREL(lock.listLock)
  14                 for(;;)
  15                 {
  16                         check owner
  17                         mov eax, 1
  18                         lock cmpxchg lock.lock, eax
  19                         if(!eax)        break;  // got lock
  20                         Threads_Sleep();
  21                 }
  22         }
  23
  24 LONGREL()
  25         lock and lock.lock, 0
  26         pop off front of list, free entry, wake thread