- We cannot access the OwnerTable without locking the resource. - The shared waiters may wait also on the semaphore. It makes no sense to boost a waiting thread. - The thread header is initialized like KeWaitForSingleObject (?, ?, ?, TRUE, ?). During the boost, possible the dispatcher lock is released but the thread block (WaitNext) isn't changed. Modified: trunk/reactos/ntoskrnl/ex/resource.c _____
Modified: trunk/reactos/ntoskrnl/ex/resource.c --- trunk/reactos/ntoskrnl/ex/resource.c 2006-01-11 22:40:31 UTC (rev 20792) +++ trunk/reactos/ntoskrnl/ex/resource.c 2006-01-11 23:22:15 UTC (rev 20793) @@ -535,6 +535,11 @@
* @remarks None. * *--*/ +#if 0 + +/* + * Disabled, read the comments bellow. + */ VOID FASTCALL ExpBoostOwnerThread(IN PKTHREAD Thread, @@ -570,6 +575,7 @@ } } } +#endif
/*++ * @name ExpWaitForResource @@ -596,7 +602,6 @@ ULONG Size, WaitCount = 0; KIRQL OldIrql; POWNER_ENTRY Owner; - PKTHREAD OwnerThread, Thread; NTSTATUS Status; LARGE_INTEGER Timeout;
@@ -664,10 +669,20 @@ ExReleaseResourceLock(&Resource->SpinLock, OldIrql); #endif } +#if 0 +/* + * Disabled because: + * - We cannot access the OwnerTable without locking the resource. + * - The shared waiters may wait also on the semaphore. It makes no sense to boost a waiting thread. + * - The thread header is initialized like KeWaitForSingleObject (?, ?, ?, TRUE, ?). + * During the boost, possible the dispatcher lock is released but the thread block (WaitNext) isn't changed. + */
/* Check if we can boost */ if (!(Resource->Flag & ResourceHasDisabledPriorityBoost)) { + PKTHREAD Thread, OwnerThread; + /* Get the current kernel thread and lock the dispatcher */ Thread = KeGetCurrentThread(); Thread->WaitIrql = KeAcquireDispatcherDatabaseLock(); @@ -700,6 +715,7 @@ } } } +#endif } }
@@ -881,10 +897,20 @@ Resource, Wait); if (!Resource->ActiveCount) { - /* Nobody owns it, so let's take control */ + if (Resource->NumberOfSharedWaiters == 0) + { + Owner = &Resource->OwnerThreads[1]; + } + else + { + /* Find a free entry */ + Owner = ExpFindFreeEntry(Resource, &OldIrql); + if (!Owner) goto TryAcquire; + } + + Owner->OwnerThread = Thread; + Owner->OwnerCount = 1; Resource->ActiveCount = 1; - Resource->OwnerThreads[1].OwnerThread = Thread; - Resource->OwnerThreads[1].OwnerCount = 1;
/* Release the lock and return */ ExReleaseResourceLock(&Resource->SpinLock, OldIrql); @@ -946,7 +972,7 @@ { /* Release the lock and return */ ExReleaseResourceLock(&Resource->SpinLock, OldIrql); - return TRUE; + return FALSE; }
/* Check if we have a shared waiters semaphore */ @@ -1769,6 +1795,7 @@ { /* Decrement owner count and check if we're done */ ASSERT(Resource->OwnerThreads[0].OwnerCount > 0); + ASSERT(Resource->ActiveCount == 1); if (--Resource->OwnerThreads[0].OwnerCount) { /* Done, release lock! */ @@ -1779,45 +1806,42 @@ /* Clear the owner */ Resource->OwnerThreads[0].OwnerThread = 0;
- /* See if the resource isn't being owned anymore */ - ASSERT(Resource->ActiveCount > 0); - if (!(--Resource->ActiveCount)) + /* Check if there are shared waiters */ + if (IsSharedWaiting(Resource)) { - /* Check if there are shared waiters */ - if (IsSharedWaiting(Resource)) - { - /* Remove the exclusive flag */ - Resource->Flag &= ~ResourceOwnedExclusive; + /* Remove the exclusive flag */ + Resource->Flag &= ~ResourceOwnedExclusive;
- /* Give ownage to another thread */ - Count = Resource->NumberOfSharedWaiters; - Resource->ActiveCount = (USHORT)Count; - Resource->NumberOfSharedWaiters = 0; + /* Give ownage to another thread */ + Count = Resource->NumberOfSharedWaiters; + Resource->ActiveCount = (USHORT)Count; + Resource->NumberOfSharedWaiters = 0;
- /* Release lock and let someone else have it */ - ExReleaseResourceLock(&Resource->SpinLock, OldIrql); - KeReleaseSemaphore(Resource->SharedWaiters, 0, Count, FALSE); - return; - } - else if (IsExclusiveWaiting(Resource)) - { - /* Give exclusive access */ - Resource->OwnerThreads[0].OwnerThread = 1; - Resource->OwnerThreads[0].OwnerCount = 1; - Resource->ActiveCount = 1; - Resource->NumberOfExclusiveWaiters--; + /* Release lock and let someone else have it */ + ExReleaseResourceLock(&Resource->SpinLock, OldIrql); + KeReleaseSemaphore(Resource->SharedWaiters, 0, Count, FALSE); + return; + } + else if (IsExclusiveWaiting(Resource)) + { + /* Give exclusive access */ + Resource->OwnerThreads[0].OwnerThread = 1; + Resource->OwnerThreads[0].OwnerCount = 1; + Resource->ActiveCount = 1; + Resource->NumberOfExclusiveWaiters--;
- /* Release the lock and give it away */ - ExReleaseResourceLock(&Resource->SpinLock, OldIrql); - KeSetEventBoostPriority(Resource->ExclusiveWaiters, - (PKTHREAD*) - &Resource->OwnerThreads[0].OwnerThread); - return; - } + /* Release the lock and give it away */ + ExReleaseResourceLock(&Resource->SpinLock, OldIrql); + KeSetEventBoostPriority(Resource->ExclusiveWaiters, + (PKTHREAD*) + &Resource->OwnerThreads[0].OwnerThread); + return; + }
- /* Remove the exclusive flag */ - Resource->Flag &= ~ResourceOwnedExclusive; - } + /* Remove the exclusive flag */ + Resource->Flag &= ~ResourceOwnedExclusive; + + Resource->ActiveCount = 0; } else { @@ -1827,11 +1851,6 @@ /* Found it, get owner */ Owner = &Resource->OwnerThreads[1]; } - else if (Resource->OwnerThreads[0].OwnerThread == Thread) - { - /* Found it on the second list, get owner */ - Owner = &Resource->OwnerThreads[0]; - } else { /* Not in the list, do a full table look up */
-
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