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- Implemented Queued and In-Stack Queued Spinlocks (at DPC-Level). See "Windows Internals II" Chapter 4, Pages 25-27.

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svn path=/trunk/; revision=20573
This commit is contained in:
Alex Ionescu 2006-01-05 13:12:48 +00:00
parent 4c4d352a5e
commit 5bba25c90e
1 changed files with 80 additions and 4 deletions
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84
reactos/ntoskrnl/ke/spinlock.c
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@ -18,6 +18,9 @@
#undef KefReleaseSpinLockFromDpcLevel
#undef KeReleaseSpinLockFromDpcLevel
#define LQ_WAIT 1
#define LQ_OWN 2
/* FUNCTIONS ***************************************************************/
/*
@ -190,25 +193,98 @@ KiReleaseSpinLock(PKSPIN_LOCK SpinLock)
#endif
}
VOID
FASTCALL
KeAcquireQueuedSpinLockAtDpcLevel(IN PKLOCK_QUEUE_HANDLE LockHandle)
{
#ifdef CONFIG_SMP
PKSPIN_LOCK_QUEUE Prev;
/* Set the new lock */
Prev = (PKSPIN_LOCK_QUEUE)
InterlockedExchange((PLONG)LockHandle->LockQueue.Lock,
(LONG)LockHandle);
if (!Prev)
{
/* There was nothing there before. We now own it */
*(ULONG_PTR*)&LockHandle->LockQueue.Lock |= LQ_OWN;
return;
}
/* Set the wait flag */
*(ULONG_PTR*)&LockHandle->LockQueue.Lock |= LQ_WAIT;
/* Link us */
Prev->Next = (PKSPIN_LOCK_QUEUE)LockHandle;
/* Loop and wait */
while ( *(ULONG_PTR*)&LockHandle->LockQueue.Lock & LQ_WAIT) YieldProcessor();
return;
#endif
}
VOID
FASTCALL
KeReleaseQueuedSpinLockFromDpcLevel(IN PKLOCK_QUEUE_HANDLE LockHandle)
{
#ifdef CONFIG_SMP
KSPIN_LOCK LockVal;
PKSPIN_LOCK_QUEUE Waiter;
/* Remove own and wait flags */
*(ULONG_PTR*)&LockHandle->LockQueue.Lock &= ~(LQ_OWN | LQ_WAIT);
LockVal = *LockHandle->LockQueue.Lock;
/* Check if we already own it */
if (LockVal == (KSPIN_LOCK)LockHandle)
{
/* Disown it */
LockVal = (KSPIN_LOCK)
InterlockedCompareExchangePointer(LockHandle->LockQueue.Lock,
NULL,
LockHandle);
}
if (LockVal == (KSPIN_LOCK)LockHandle) return;
/* Need to wait for it */
Waiter = LockHandle->LockQueue.Next;
while (!Waiter)
{
YieldProcessor();
Waiter = LockHandle->LockQueue.Next;
}
/* It's gone */
*(ULONG_PTR*)&Waiter->Lock ^= (LQ_OWN | LQ_WAIT);
LockHandle->LockQueue.Next = NULL;
#endif
}
/*
* @unimplemented
* @implemented
*/
VOID
FASTCALL
KeAcquireInStackQueuedSpinLockAtDpcLevel(IN PKSPIN_LOCK SpinLock,
IN PKLOCK_QUEUE_HANDLE LockHandle)
{
UNIMPLEMENTED;
/* Set it up properly */
LockHandle->LockQueue.Next = NULL;
LockHandle->LockQueue.Lock = SpinLock;
KeAcquireQueuedSpinLockAtDpcLevel((PKLOCK_QUEUE_HANDLE)
&LockHandle->LockQueue.Next);
}
/*
* @unimplemented
* @implemented
*/
VOID
FASTCALL
KeReleaseInStackQueuedSpinLockFromDpcLevel(IN PKLOCK_QUEUE_HANDLE LockHandle)
{
UNIMPLEMENTED;
/* Call the internal function */
KeReleaseQueuedSpinLockFromDpcLevel((PKLOCK_QUEUE_HANDLE)
&LockHandle->LockQueue.Next);
}
/* EOF */