RunQemu - Add AHCI support
[tpg/acess2.git] / 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

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