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https://github.com/reactos/reactos.git
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2285 lines
65 KiB
C
2285 lines
65 KiB
C
/*
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* PROJECT: ReactOS Kernel
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* LICENSE: GPL - See COPYING in the top level directory
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* FILE: ntoskrnl/ex/resource.c
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* PURPOSE: Executive Resource Implementation
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* PROGRAMMERS: Alex Ionescu (alex.ionescu@reactos.org)
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*/
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/* INCLUDES *****************************************************************/
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#include <ntoskrnl.h>
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#define NDEBUG
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#include <debug.h>
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/* Macros for reading resource flags */
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#define IsExclusiveWaiting(r) (r->NumberOfExclusiveWaiters > 0)
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#define IsSharedWaiting(r) (r->NumberOfSharedWaiters > 0)
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#define IsOwnedExclusive(r) (r->Flag & ResourceOwnedExclusive)
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#define IsBoostAllowed(r) (!(r->Flag & ResourceHasDisabledPriorityBoost))
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#if (!(defined(CONFIG_SMP)) && !(DBG))
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FORCEINLINE
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VOID
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ExAcquireResourceLock(IN PERESOURCE Resource,
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IN PKLOCK_QUEUE_HANDLE LockHandle)
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{
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UNREFERENCED_PARAMETER(Resource);
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UNREFERENCED_PARAMETER(LockHandle);
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/* Simply disable interrupts */
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_disable();
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}
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FORCEINLINE
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VOID
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ExReleaseResourceLock(IN PERESOURCE Resource,
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IN PKLOCK_QUEUE_HANDLE LockHandle)
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{
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UNREFERENCED_PARAMETER(Resource);
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UNREFERENCED_PARAMETER(LockHandle);
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/* Simply enable interrupts */
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_enable();
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}
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#else
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FORCEINLINE
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VOID
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ExAcquireResourceLock(IN PERESOURCE Resource,
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IN PKLOCK_QUEUE_HANDLE LockHandle)
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{
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/* Acquire the lock */
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KeAcquireInStackQueuedSpinLock(&Resource->SpinLock, LockHandle);
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}
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FORCEINLINE
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VOID
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ExReleaseResourceLock(IN PERESOURCE Resource,
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IN PKLOCK_QUEUE_HANDLE LockHandle)
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{
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UNREFERENCED_PARAMETER(Resource);
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/* Release the lock */
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KeReleaseInStackQueuedSpinLock(LockHandle);
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}
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#endif
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/* DATA***********************************************************************/
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LARGE_INTEGER ExShortTime = {{-100000, -1}};
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LARGE_INTEGER ExpTimeout;
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ULONG ExpResourceTimeoutCount = 90 * 3600 / 2;
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KSPIN_LOCK ExpResourceSpinLock;
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LIST_ENTRY ExpSystemResourcesList;
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BOOLEAN ExResourceStrict = TRUE;
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/* PRIVATE FUNCTIONS *********************************************************/
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#if DBG
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/*++
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* @name ExpVerifyResource
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*
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* The ExpVerifyResource routine verifies the correctness of an ERESOURCE
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*
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* @param Resource
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* Pointer to the resource being verified.
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*
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* @return None.
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*
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* @remarks Only present on DBG builds.
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*
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*--*/
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VOID
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NTAPI
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ExpVerifyResource(IN PERESOURCE Resource)
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{
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/* Verify the resource data */
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ASSERT((((ULONG_PTR)Resource) & (sizeof(ULONG_PTR) - 1)) == 0);
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ASSERT(!Resource->SharedWaiters ||
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Resource->SharedWaiters->Header.Type == SemaphoreObject);
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ASSERT(!Resource->SharedWaiters ||
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Resource->SharedWaiters->Header.Size == (sizeof(KSEMAPHORE) / sizeof(ULONG)));
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ASSERT(!Resource->ExclusiveWaiters ||
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Resource->ExclusiveWaiters->Header.Type == SynchronizationEvent);
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ASSERT(!Resource->ExclusiveWaiters ||
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Resource->ExclusiveWaiters->Header.Size == (sizeof(KEVENT) / sizeof(ULONG)));
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}
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/*++
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* @name ExpCheckForApcsDisabled
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*
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* The ExpCheckForApcsDisabled routine checks if Kernel APCs are still
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* enabled when they should be disabled, and optionally breakpoints.
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*
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* @param Irql
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* Specifies the IRQL during the acquire attempt.
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*
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* @param Resource
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* Pointer to the resource being checked.
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*
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* @param Thread
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* Pointer to the thread being checked.
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*
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* @return None.
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*
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* @remarks Only present on DBG builds. Depends on ExResourceStrict value.
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*
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*--*/
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VOID
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NTAPI
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ExpCheckForApcsDisabled(IN KIRQL Irql,
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IN PERESOURCE Resource,
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IN PKTHREAD Thread)
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{
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/* Check if we should care and check if we should break */
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if ((ExResourceStrict) &&
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(Irql < APC_LEVEL) &&
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!(((PETHREAD)Thread)->SystemThread) &&
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!(Thread->CombinedApcDisable))
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{
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/* Bad! */
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DPRINT1("EX: resource: APCs still enabled before resource %p acquire/release "
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"!!!\n", Resource);
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DbgBreakPoint();
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}
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}
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#else
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#define ExpVerifyResource(r)
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#define ExpCheckForApcsDisabled(b,r,t)
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#endif
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/*++
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* @name ExpResourceInitialization
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*
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* The ExpResourceInitialization routine initializes resources for use.
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*
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* @param None.
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*
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* @return None.
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*
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* @remarks This routine should only be called once, during system startup.
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*
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*--*/
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CODE_SEG("INIT")
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VOID
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NTAPI
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ExpResourceInitialization(VOID)
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{
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/* Setup the timeout */
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ExpTimeout.QuadPart = Int32x32To64(4, -10000000);
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InitializeListHead(&ExpSystemResourcesList);
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KeInitializeSpinLock(&ExpResourceSpinLock);
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}
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/*++
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* @name ExpAllocateExclusiveWaiterEvent
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*
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* The ExpAllocateExclusiveWaiterEvent routine creates the event that will
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* be used by exclusive waiters on the resource.
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*
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* @param Resource
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* Pointer to the resource.
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*
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* @param LockHandle
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* Pointer to in-stack queued spinlock.
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*
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* @return None.
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*
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* @remarks The pointer to the event must be atomically set.
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*
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*--*/
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VOID
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NTAPI
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ExpAllocateExclusiveWaiterEvent(IN PERESOURCE Resource,
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IN PKLOCK_QUEUE_HANDLE LockHandle)
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{
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PKEVENT Event;
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/* Release the lock */
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ExReleaseResourceLock(Resource, LockHandle);
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/* Loop as long as we keep running out of memory */
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do
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{
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/* Allocate the event */
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Event = ExAllocatePoolWithTag(NonPagedPool,
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sizeof(KEVENT),
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TAG_RESOURCE_EVENT);
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if (Event)
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{
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/* Initialize it */
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KeInitializeEvent(Event, SynchronizationEvent, FALSE);
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/* Set it */
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if (InterlockedCompareExchangePointer((PVOID*)&Resource->ExclusiveWaiters,
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Event,
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NULL))
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{
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/* Someone already set it, free our event */
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DPRINT1("WARNING: Handling race condition\n");
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ExFreePoolWithTag(Event, TAG_RESOURCE_EVENT);
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}
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break;
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}
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/* Wait a bit before trying again */
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KeDelayExecutionThread(KernelMode, FALSE, &ExShortTime);
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} while (TRUE);
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/* Re-acquire the lock */
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ExAcquireResourceLock(Resource, LockHandle);
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}
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/*++
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* @name ExpAllocateSharedWaiterSemaphore
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*
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* The ExpAllocateSharedWaiterSemaphore routine creates the semaphore that
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* will be used by shared waiters on the resource.
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*
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* @param Resource
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* Pointer to the resource.
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*
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* @param LockHandle
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* Pointer to in-stack queued spinlock.
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*
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* @return None.
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*
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* @remarks The pointer to the semaphore must be atomically set.
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*
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*--*/
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VOID
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NTAPI
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ExpAllocateSharedWaiterSemaphore(IN PERESOURCE Resource,
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IN PKLOCK_QUEUE_HANDLE LockHandle)
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{
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PKSEMAPHORE Semaphore;
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/* Release the lock */
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ExReleaseResourceLock(Resource, LockHandle);
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/* Loop as long as we keep running out of memory */
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do
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{
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/* Allocate the semaphore */
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Semaphore = ExAllocatePoolWithTag(NonPagedPool,
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sizeof(KSEMAPHORE),
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TAG_RESOURCE_SEMAPHORE);
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if (Semaphore)
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{
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/* Initialize it */
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KeInitializeSemaphore(Semaphore, 0, MAXLONG);
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/* Set it */
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if (InterlockedCompareExchangePointer((PVOID*)&Resource->SharedWaiters,
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Semaphore,
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NULL))
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{
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/* Someone already set it, free our semaphore */
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DPRINT1("WARNING: Handling race condition\n");
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ExFreePoolWithTag(Semaphore, TAG_RESOURCE_SEMAPHORE);
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}
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break;
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}
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/* Wait a bit before trying again */
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KeDelayExecutionThread(KernelMode, FALSE, &ExShortTime);
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} while (TRUE);
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/* Re-acquire the lock */
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ExAcquireResourceLock(Resource, LockHandle);
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}
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/*++
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* @name ExpExpandResourceOwnerTable
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*
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* The ExpExpandResourceOwnerTable routine expands the owner table of the
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* specified resource.
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*
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* @param Resource
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* Pointer to the resource.
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*
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* @param LockHandle
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* Pointer to in-stack queued spinlock.
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*
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* @return None.
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*
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* @remarks None.
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*
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*--*/
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VOID
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NTAPI
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ExpExpandResourceOwnerTable(IN PERESOURCE Resource,
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IN PKLOCK_QUEUE_HANDLE LockHandle)
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{
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POWNER_ENTRY Owner, Table;
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KIRQL OldIrql;
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ULONG NewSize, OldSize;
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/* Get the owner table */
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Owner = Resource->OwnerTable;
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if (!Owner)
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{
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/* Start with the default size of 3 */
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OldSize = 0;
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NewSize = 3;
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}
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else
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{
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/* Add 4 more entries */
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OldSize = Owner->TableSize;
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NewSize = OldSize + 4;
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}
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/* Release the lock */
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ExReleaseResourceLock(Resource, LockHandle);
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/* Allocate memory for the table */
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Table = ExAllocatePoolWithTag(NonPagedPool,
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NewSize * sizeof(OWNER_ENTRY),
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TAG_RESOURCE_TABLE);
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/* Zero the table */
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RtlZeroMemory(Table + OldSize,
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(NewSize - OldSize) * sizeof(OWNER_ENTRY));
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/* Lock the resource */
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ExAcquireResourceLock(Resource, LockHandle);
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/* Make sure nothing has changed */
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if ((Owner != Resource->OwnerTable) ||
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((Owner) && (OldSize != Owner->TableSize)))
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{
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/* Resource changed while we weren't holding the lock; bail out */
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ExReleaseResourceLock(Resource, LockHandle);
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ExFreePoolWithTag(Table, TAG_RESOURCE_TABLE);
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}
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else
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{
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/* Copy the table */
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if (Owner) RtlCopyMemory(Table, Owner, OldSize * sizeof(OWNER_ENTRY));
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/* Acquire dispatcher lock to prevent thread boosting */
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OldIrql = KiAcquireDispatcherLock();
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/* Set the new table data */
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Table->TableSize = NewSize;
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Resource->OwnerTable = Table;
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/* Release dispatcher lock */
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KiReleaseDispatcherLock(OldIrql);
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/* Sanity check */
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ExpVerifyResource(Resource);
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/* Release lock */
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ExReleaseResourceLock(Resource, LockHandle);
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/* Free the old table */
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if (Owner) ExFreePoolWithTag(Owner, TAG_RESOURCE_TABLE);
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/* Set the resource index */
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if (!OldSize) OldSize = 1;
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}
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/* Set the resource index */
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KeGetCurrentThread()->ResourceIndex = (UCHAR)OldSize;
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/* Lock the resource again */
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ExAcquireResourceLock(Resource, LockHandle);
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}
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/*++
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* @name ExpFindFreeEntry
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*
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* The ExpFindFreeEntry routine locates an empty owner entry in the
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* specified resource. If none was found, then the owner table is
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* expanded.
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*
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* @param Resource
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* Pointer to the resource.
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*
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* @param LockHandle
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* Pointer to in-stack queued spinlock.
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*
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* @return Pointer to an empty OWNER_ENTRY structure.
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*
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* @remarks None.
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*
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*--*/
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POWNER_ENTRY
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FASTCALL
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ExpFindFreeEntry(IN PERESOURCE Resource,
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IN PKLOCK_QUEUE_HANDLE LockHandle)
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{
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POWNER_ENTRY Owner, Limit;
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/* Sanity check */
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ASSERT(LockHandle != 0);
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ASSERT(Resource->OwnerEntry.OwnerThread != 0);
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/* Get the current table pointer */
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Owner = Resource->OwnerTable;
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if (Owner)
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{
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/* Set the limit, move to the next owner and loop owner entries */
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Limit = &Owner[Owner->TableSize];
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Owner++;
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while (Owner->OwnerThread)
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{
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/* Move to the next one */
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Owner++;
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/* Check if the entry is free */
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if (Owner == Limit) goto Expand;
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}
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/* Update the resource entry */
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KeGetCurrentThread()->ResourceIndex = (UCHAR)(Owner - Resource->OwnerTable);
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}
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else
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{
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Expand:
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/* No free entry, expand the table */
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ExpExpandResourceOwnerTable(Resource, LockHandle);
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Owner = NULL;
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}
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/* Return the entry found */
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return Owner;
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}
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/*++
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* @name ExpFindEntryForThread
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*
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* The ExpFindEntryForThread routine locates the owner entry associated with
|
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* the specified thread in the given resource. If none was found, then the
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* owner table is expanded.
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*
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* @param Resource
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* Pointer to the resource.
|
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*
|
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* @param Thread
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* Pointer to the thread to find.
|
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*
|
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* @param LockHandle
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* Pointer to in-stack queued spinlock.
|
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*
|
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* @return Pointer to an empty OWNER_ENTRY structure.
|
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*
|
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* @remarks None.
|
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*
|
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*--*/
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POWNER_ENTRY
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FASTCALL
|
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ExpFindEntryForThread(IN PERESOURCE Resource,
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IN ERESOURCE_THREAD Thread,
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IN PKLOCK_QUEUE_HANDLE LockHandle,
|
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IN BOOLEAN FirstEntryInelligible)
|
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{
|
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POWNER_ENTRY FreeEntry, Owner, Limit;
|
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/* Start by looking in the static array */
|
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Owner = &Resource->OwnerEntry;
|
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if (Owner->OwnerThread == Thread) return Owner;
|
||
|
||
/* Check if this is a free entry */
|
||
if ((FirstEntryInelligible) || (Owner->OwnerThread))
|
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{
|
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/* No free entry */
|
||
FreeEntry = NULL;
|
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}
|
||
else
|
||
{
|
||
/* Use the first entry as our free entry */
|
||
FreeEntry = Owner;
|
||
}
|
||
|
||
/* Get the current table pointer */
|
||
Owner = Resource->OwnerTable;
|
||
if (Owner)
|
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{
|
||
/* Set the limit, move to the next owner and loop owner entries */
|
||
Limit = &Owner[Owner->TableSize];
|
||
Owner++;
|
||
while (Owner->OwnerThread != Thread)
|
||
{
|
||
/* Check if we don't have a free entry */
|
||
if (!FreeEntry)
|
||
{
|
||
/* Check if this entry is free */
|
||
if (!Owner->OwnerThread)
|
||
{
|
||
/* Save it as our free entry */
|
||
FreeEntry = Owner;
|
||
}
|
||
}
|
||
|
||
/* Move to the next one */
|
||
Owner++;
|
||
|
||
/* Check if the entry is free */
|
||
if (Owner == Limit) goto Expand;
|
||
}
|
||
|
||
/* Update the resource entry */
|
||
KeGetCurrentThread()->ResourceIndex = (UCHAR)(Owner - Resource->OwnerTable);
|
||
return Owner;
|
||
}
|
||
else
|
||
{
|
||
Expand:
|
||
/* Check if it's OK to do an expansion */
|
||
if (!LockHandle) return NULL;
|
||
|
||
/* If we found a free entry by now, return it */
|
||
if (FreeEntry)
|
||
{
|
||
/* Set the resource index */
|
||
KeGetCurrentThread()->ResourceIndex = (UCHAR)(FreeEntry - Resource->OwnerTable);
|
||
return FreeEntry;
|
||
}
|
||
|
||
/* No free entry, expand the table */
|
||
ExpExpandResourceOwnerTable(Resource, LockHandle);
|
||
return NULL;
|
||
}
|
||
}
|
||
|
||
/*++
|
||
* @name ExpBoostOwnerThread
|
||
*
|
||
* The ExpBoostOwnerThread routine increases the priority of a waiting
|
||
* thread in an attempt to fight a possible deadlock.
|
||
*
|
||
* @param Thread
|
||
* Pointer to the current thread.
|
||
*
|
||
* @param OwnerThread
|
||
* Pointer to thread that owns the resource.
|
||
*
|
||
* @return None.
|
||
*
|
||
* @remarks None.
|
||
*
|
||
*--*/
|
||
VOID
|
||
FASTCALL
|
||
ExpBoostOwnerThread(IN PKTHREAD Thread,
|
||
IN PKTHREAD OwnerThread)
|
||
{
|
||
/* Make sure the owner thread is a pointer, not an ID */
|
||
if (!((ULONG_PTR)OwnerThread & 0x3))
|
||
{
|
||
/* Check if we can actually boost it */
|
||
if ((OwnerThread->Priority < Thread->Priority) &&
|
||
(OwnerThread->Priority < 14))
|
||
{
|
||
/* Acquire the thread lock */
|
||
KiAcquireThreadLock(Thread);
|
||
|
||
/* Set the new priority */
|
||
OwnerThread->PriorityDecrement += 14 - OwnerThread->Priority;
|
||
|
||
/* Update quantum */
|
||
OwnerThread->Quantum = OwnerThread->QuantumReset;
|
||
|
||
/* Update the kernel state */
|
||
KiSetPriorityThread(OwnerThread, 14);
|
||
|
||
/* Release the thread lock */
|
||
KiReleaseThreadLock(Thread);
|
||
}
|
||
}
|
||
}
|
||
|
||
/*++
|
||
* @name ExpWaitForResource
|
||
*
|
||
* The ExpWaitForResource routine performs a wait on the specified resource.
|
||
*
|
||
* @param Resource
|
||
* Pointer to the resource to wait on.
|
||
*
|
||
* @param OwnerThread
|
||
* Pointer to object (exclusive event or shared semaphore) to wait on.
|
||
*
|
||
* @return None.
|
||
*
|
||
* @remarks None.
|
||
*
|
||
*--*/
|
||
VOID
|
||
FASTCALL
|
||
ExpWaitForResource(IN PERESOURCE Resource,
|
||
IN PVOID Object)
|
||
{
|
||
ULONG i;
|
||
ULONG Size;
|
||
POWNER_ENTRY Owner;
|
||
ULONG WaitCount = 0;
|
||
NTSTATUS Status;
|
||
LARGE_INTEGER Timeout;
|
||
PKTHREAD Thread, OwnerThread;
|
||
#if DBG
|
||
KLOCK_QUEUE_HANDLE LockHandle;
|
||
#endif
|
||
|
||
/* Increase contention count and use a 5 second timeout */
|
||
Resource->ContentionCount++;
|
||
Timeout.QuadPart = 500 * -10000;
|
||
for (;;)
|
||
{
|
||
/* Wait for ownership */
|
||
Status = KeWaitForSingleObject(Object,
|
||
WrResource,
|
||
KernelMode,
|
||
FALSE,
|
||
&Timeout);
|
||
if (Status != STATUS_TIMEOUT) break;
|
||
|
||
/* Increase wait count */
|
||
WaitCount++;
|
||
Timeout = ExpTimeout;
|
||
|
||
/* Check if we've exceeded the limit */
|
||
if (WaitCount > ExpResourceTimeoutCount)
|
||
{
|
||
/* Reset wait count */
|
||
WaitCount = 0;
|
||
#if DBG
|
||
/* Lock the resource */
|
||
ExAcquireResourceLock(Resource, &LockHandle);
|
||
|
||
/* Dump debug information */
|
||
DPRINT1("Resource @ %p\n", Resource);
|
||
DPRINT1(" ActiveEntries = %04lx Flags = %s%s%s\n",
|
||
Resource->ActiveEntries,
|
||
IsOwnedExclusive(Resource) ? "IsOwnedExclusive " : "",
|
||
IsSharedWaiting(Resource) ? "SharedWaiter " : "",
|
||
IsExclusiveWaiting(Resource) ? "ExclusiveWaiter " : "");
|
||
DPRINT1(" NumberOfExclusiveWaiters = %04lx\n",
|
||
Resource->NumberOfExclusiveWaiters);
|
||
DPRINT1(" Thread = %08lx, Count = %02x\n",
|
||
Resource->OwnerEntry.OwnerThread,
|
||
Resource->OwnerEntry.OwnerCount);
|
||
|
||
/* Dump out the table too */
|
||
Owner = Resource->OwnerTable;
|
||
if (Owner)
|
||
{
|
||
/* Loop every entry */
|
||
Size = Owner->TableSize;
|
||
for (i = 1; i < Size; i++)
|
||
{
|
||
/* Print the data */
|
||
Owner++;
|
||
DPRINT1(" Thread = %08lx, Count = %02x\n",
|
||
Owner->OwnerThread,
|
||
Owner->OwnerCount);
|
||
}
|
||
}
|
||
|
||
/* Break */
|
||
DbgBreakPoint();
|
||
DPRINT1("EX - Rewaiting\n");
|
||
ExReleaseResourceLock(Resource, &LockHandle);
|
||
#endif
|
||
}
|
||
|
||
/* Check if we can boost */
|
||
if (IsBoostAllowed(Resource))
|
||
{
|
||
/* Get the current kernel thread and lock the dispatcher */
|
||
Thread = KeGetCurrentThread();
|
||
Thread->WaitIrql = KiAcquireDispatcherLock();
|
||
Thread->WaitNext = TRUE;
|
||
|
||
/* Get the owner thread and boost it */
|
||
OwnerThread = (PKTHREAD)Resource->OwnerEntry.OwnerThread;
|
||
if (OwnerThread) ExpBoostOwnerThread(Thread, OwnerThread);
|
||
|
||
/* If it's a shared resource */
|
||
if (!IsOwnedExclusive(Resource))
|
||
{
|
||
/* Get the table */
|
||
Owner = Resource->OwnerTable;
|
||
if (Owner)
|
||
{
|
||
/* Loop every entry */
|
||
Size = Owner->TableSize;
|
||
for (i = 1; i < Size; i++)
|
||
{
|
||
/* Move to next entry */
|
||
Owner++;
|
||
|
||
/* Get the thread */
|
||
OwnerThread = (PKTHREAD)Owner->OwnerThread;
|
||
|
||
/* Boost it */
|
||
if (OwnerThread) ExpBoostOwnerThread(Thread, OwnerThread);
|
||
}
|
||
}
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
/* FUNCTIONS *****************************************************************/
|
||
|
||
/*++
|
||
* @name ExAcquireResourceExclusiveLite
|
||
* @implemented NT4
|
||
*
|
||
* The ExAcquireResourceExclusiveLite routine acquires the given resource
|
||
* for exclusive access by the calling thread.
|
||
*
|
||
* @param Resource
|
||
* Pointer to the resource to acquire.
|
||
*
|
||
* @param Wait
|
||
* Specifies the routine's behavior whenever the resource cannot be
|
||
* acquired immediately.
|
||
*
|
||
* @return TRUE if the resource is acquired. FALSE if the input Wait is FALSE
|
||
* and exclusive access cannot be granted immediately.
|
||
*
|
||
* @remarks The caller can release the resource by calling either
|
||
* ExReleaseResourceLite or ExReleaseResourceForThreadLite.
|
||
*
|
||
* Normal kernel APC delivery must be disabled before calling this
|
||
* routine. Disable normal kernel APC delivery by calling
|
||
* KeEnterCriticalRegion. Delivery must remain disabled until the
|
||
* resource is released, at which point it can be reenabled by calling
|
||
* KeLeaveCriticalRegion.
|
||
*
|
||
* For better performance, call ExTryToAcquireResourceExclusiveLite,
|
||
* rather than calling ExAcquireResourceExclusiveLite with Wait set
|
||
* to FALSE.
|
||
*
|
||
* Callers of ExAcquireResourceExclusiveLite must be running at IRQL <
|
||
* DISPATCH_LEVEL.
|
||
*
|
||
*--*/
|
||
BOOLEAN
|
||
NTAPI
|
||
ExAcquireResourceExclusiveLite(IN PERESOURCE Resource,
|
||
IN BOOLEAN Wait)
|
||
{
|
||
KLOCK_QUEUE_HANDLE LockHandle;
|
||
ERESOURCE_THREAD Thread;
|
||
BOOLEAN Success;
|
||
|
||
/* Sanity check */
|
||
ASSERT((Resource->Flag & ResourceNeverExclusive) == 0);
|
||
|
||
/* Get the thread */
|
||
Thread = ExGetCurrentResourceThread();
|
||
|
||
/* Sanity check and validation */
|
||
ASSERT(KeIsExecutingDpc() == FALSE);
|
||
ExpVerifyResource(Resource);
|
||
|
||
/* Acquire the lock */
|
||
ExAcquireResourceLock(Resource, &LockHandle);
|
||
ExpCheckForApcsDisabled(LockHandle.OldIrql, Resource, (PKTHREAD)Thread);
|
||
|
||
/* Check if there is a shared owner or exclusive owner */
|
||
TryAcquire:
|
||
if (Resource->ActiveEntries)
|
||
{
|
||
/* Check if it's exclusively owned, and we own it */
|
||
if ((IsOwnedExclusive(Resource)) &&
|
||
(Resource->OwnerEntry.OwnerThread == Thread))
|
||
{
|
||
/* Increase the owning count */
|
||
Resource->OwnerEntry.OwnerCount++;
|
||
Success = TRUE;
|
||
}
|
||
else
|
||
{
|
||
/*
|
||
* If the caller doesn't want us to wait, we can't acquire the
|
||
* resource because someone else then us owns it. If we can wait,
|
||
* then we'll wait.
|
||
*/
|
||
if (!Wait)
|
||
{
|
||
Success = FALSE;
|
||
}
|
||
else
|
||
{
|
||
/* Check if it has exclusive waiters */
|
||
if (!Resource->ExclusiveWaiters)
|
||
{
|
||
/* It doesn't, allocate the event and try acquiring again */
|
||
ExpAllocateExclusiveWaiterEvent(Resource, &LockHandle);
|
||
goto TryAcquire;
|
||
}
|
||
|
||
/* Has exclusive waiters, wait on it */
|
||
Resource->NumberOfExclusiveWaiters++;
|
||
ExReleaseResourceLock(Resource, &LockHandle);
|
||
ExpWaitForResource(Resource, Resource->ExclusiveWaiters);
|
||
|
||
/* Set owner and return success */
|
||
Resource->OwnerEntry.OwnerThread = ExGetCurrentResourceThread();
|
||
return TRUE;
|
||
}
|
||
}
|
||
}
|
||
else
|
||
{
|
||
/* Nobody owns it, so let's! */
|
||
ASSERT(Resource->ActiveEntries == 0);
|
||
ASSERT(Resource->ActiveCount == 0);
|
||
Resource->Flag |= ResourceOwnedExclusive;
|
||
Resource->ActiveEntries = 1;
|
||
Resource->ActiveCount = 1;
|
||
Resource->OwnerEntry.OwnerThread = Thread;
|
||
Resource->OwnerEntry.OwnerCount = 1;
|
||
Success = TRUE;
|
||
}
|
||
|
||
/* Release the lock and return */
|
||
ExReleaseResourceLock(Resource, &LockHandle);
|
||
return Success;
|
||
}
|
||
|
||
/*++
|
||
* @name ExAcquireResourceSharedLite
|
||
* @implemented NT4
|
||
*
|
||
* The ExAcquireResourceSharedLite routine acquires the given resource
|
||
* for shared access by the calling thread.
|
||
*
|
||
* @param Resource
|
||
* Pointer to the resource to acquire.
|
||
*
|
||
* @param Wait
|
||
* Specifies the routine's behavior whenever the resource cannot be
|
||
* acquired immediately.
|
||
*
|
||
* @return TRUE if the resource is acquired. FALSE if the input Wait is FALSE
|
||
* and exclusive access cannot be granted immediately.
|
||
*
|
||
* @remarks The caller can release the resource by calling either
|
||
* ExReleaseResourceLite or ExReleaseResourceForThreadLite.
|
||
*
|
||
* Normal kernel APC delivery must be disabled before calling this
|
||
* routine. Disable normal kernel APC delivery by calling
|
||
* KeEnterCriticalRegion. Delivery must remain disabled until the
|
||
* resource is released, at which point it can be reenabled by calling
|
||
* KeLeaveCriticalRegion.
|
||
*
|
||
* Callers of ExAcquireResourceExclusiveLite must be running at IRQL <
|
||
* DISPATCH_LEVEL.
|
||
*
|
||
*--*/
|
||
BOOLEAN
|
||
NTAPI
|
||
ExAcquireResourceSharedLite(IN PERESOURCE Resource,
|
||
IN BOOLEAN Wait)
|
||
{
|
||
KLOCK_QUEUE_HANDLE LockHandle;
|
||
ERESOURCE_THREAD Thread;
|
||
POWNER_ENTRY Owner = NULL;
|
||
BOOLEAN FirstEntryBusy;
|
||
|
||
/* Get the thread */
|
||
Thread = ExGetCurrentResourceThread();
|
||
|
||
/* Sanity check and validation */
|
||
ASSERT(KeIsExecutingDpc() == FALSE);
|
||
ExpVerifyResource(Resource);
|
||
|
||
/* Acquire the lock */
|
||
ExAcquireResourceLock(Resource, &LockHandle);
|
||
ExpCheckForApcsDisabled(LockHandle.OldIrql, Resource, (PKTHREAD)Thread);
|
||
|
||
/* Check how many active entries we've got */
|
||
while (Resource->ActiveEntries != 0)
|
||
{
|
||
/* Check if it's exclusively owned */
|
||
if (IsOwnedExclusive(Resource))
|
||
{
|
||
/* Check if we own it */
|
||
if (Resource->OwnerEntry.OwnerThread == Thread)
|
||
{
|
||
/* Increase the owning count */
|
||
Resource->OwnerEntry.OwnerCount++;
|
||
|
||
/* Release the lock and return */
|
||
ExReleaseResourceLock(Resource, &LockHandle);
|
||
return TRUE;
|
||
}
|
||
|
||
/* Find a free entry */
|
||
Owner = ExpFindFreeEntry(Resource, &LockHandle);
|
||
if (!Owner) continue;
|
||
}
|
||
else
|
||
{
|
||
/* Resource is shared, find who owns it */
|
||
FirstEntryBusy = IsExclusiveWaiting(Resource);
|
||
Owner = ExpFindEntryForThread(Resource,
|
||
Thread,
|
||
&LockHandle,
|
||
FirstEntryBusy);
|
||
if (!Owner) continue;
|
||
|
||
/* Is it us? */
|
||
if (Owner->OwnerThread == Thread)
|
||
{
|
||
/* Increase acquire count and return */
|
||
Owner->OwnerCount++;
|
||
ASSERT(Owner->OwnerCount != 0);
|
||
|
||
/* Release the lock and return */
|
||
ExReleaseResourceLock(Resource, &LockHandle);
|
||
return TRUE;
|
||
}
|
||
|
||
/* Try to find if there are exclusive waiters */
|
||
if (!FirstEntryBusy)
|
||
{
|
||
/* There are none, so acquire it */
|
||
Owner->OwnerThread = Thread;
|
||
Owner->OwnerCount = 1;
|
||
|
||
/* Check how many active entries we had */
|
||
if (Resource->ActiveEntries == 0)
|
||
{
|
||
/* Set initial counts */
|
||
ASSERT(Resource->ActiveCount == 0);
|
||
Resource->ActiveEntries = 1;
|
||
Resource->ActiveCount = 1;
|
||
}
|
||
else
|
||
{
|
||
/* Increase active entries */
|
||
ASSERT(Resource->ActiveCount == 1);
|
||
Resource->ActiveEntries++;
|
||
}
|
||
|
||
/* Release the lock and return */
|
||
ExReleaseResourceLock(Resource, &LockHandle);
|
||
return TRUE;
|
||
}
|
||
}
|
||
|
||
/* If we got here, then we need to wait. Are we allowed? */
|
||
if (!Wait)
|
||
{
|
||
/* Release the lock and return */
|
||
ExReleaseResourceLock(Resource, &LockHandle);
|
||
return FALSE;
|
||
}
|
||
|
||
/* Check if we have a shared waiters semaphore */
|
||
if (!Resource->SharedWaiters)
|
||
{
|
||
/* Allocate it and try another acquire */
|
||
ExpAllocateSharedWaiterSemaphore(Resource, &LockHandle);
|
||
}
|
||
else
|
||
{
|
||
/* We have shared waiters, wait for it */
|
||
break;
|
||
}
|
||
}
|
||
|
||
/* Did we get here because we don't have active entries? */
|
||
if (Resource->ActiveEntries == 0)
|
||
{
|
||
/* Acquire it */
|
||
ASSERT(Resource->ActiveEntries == 0);
|
||
ASSERT(Resource->ActiveCount == 0);
|
||
Resource->ActiveEntries = 1;
|
||
Resource->ActiveCount = 1;
|
||
Resource->OwnerEntry.OwnerThread = Thread;
|
||
Resource->OwnerEntry.OwnerCount = 1;
|
||
|
||
/* Release the lock and return */
|
||
ExReleaseResourceLock(Resource, &LockHandle);
|
||
return TRUE;
|
||
}
|
||
|
||
/* Now wait for the resource */
|
||
Owner->OwnerThread = Thread;
|
||
Owner->OwnerCount = 1;
|
||
Resource->NumberOfSharedWaiters++;
|
||
|
||
/* Release the lock and return */
|
||
ExReleaseResourceLock(Resource, &LockHandle);
|
||
ExpWaitForResource(Resource, Resource->SharedWaiters);
|
||
return TRUE;
|
||
}
|
||
|
||
/*++
|
||
* @name ExAcquireSharedStarveExclusive
|
||
* @implemented NT4
|
||
*
|
||
* The ExAcquireSharedStarveExclusive routine acquires the given resource
|
||
* shared access without waiting for any pending attempts to acquire
|
||
* exclusive access to the same resource.
|
||
*
|
||
* @param Resource
|
||
* Pointer to the resource to acquire.
|
||
*
|
||
* @param Wait
|
||
* Specifies the routine's behavior whenever the resource cannot be
|
||
* acquired immediately.
|
||
*
|
||
* @return TRUE if the resource is acquired. FALSE if the input Wait is FALSE
|
||
* and exclusive access cannot be granted immediately.
|
||
*
|
||
* @remarks The caller can release the resource by calling either
|
||
* ExReleaseResourceLite or ExReleaseResourceForThreadLite.
|
||
*
|
||
* Normal kernel APC delivery must be disabled before calling this
|
||
* routine. Disable normal kernel APC delivery by calling
|
||
* KeEnterCriticalRegion. Delivery must remain disabled until the
|
||
* resource is released, at which point it can be reenabled by calling
|
||
* KeLeaveCriticalRegion.
|
||
*
|
||
* Callers of ExAcquireSharedStarveExclusive usually need quick access
|
||
* to a shared resource in order to save an exclusive accessor from
|
||
* doing redundant work. For example, a file system might call this
|
||
* routine to modify a cached resource, such as a BCB pinned in the
|
||
* cache, before the Cache Manager can acquire exclusive access to the
|
||
* resource and write the cache out to disk.
|
||
*
|
||
* Callers of ExAcquireResourceExclusiveLite must be running at IRQL <
|
||
* DISPATCH_LEVEL.
|
||
*
|
||
*--*/
|
||
BOOLEAN
|
||
NTAPI
|
||
ExAcquireSharedStarveExclusive(IN PERESOURCE Resource,
|
||
IN BOOLEAN Wait)
|
||
{
|
||
KLOCK_QUEUE_HANDLE LockHandle;
|
||
ERESOURCE_THREAD Thread;
|
||
POWNER_ENTRY Owner;
|
||
|
||
/* Get the thread */
|
||
Thread = ExGetCurrentResourceThread();
|
||
|
||
/* Sanity check and validation */
|
||
ASSERT(KeIsExecutingDpc() == FALSE);
|
||
ExpVerifyResource(Resource);
|
||
|
||
/* Acquire the lock */
|
||
ExAcquireResourceLock(Resource, &LockHandle);
|
||
|
||
/* See if anyone owns it */
|
||
TryAcquire:
|
||
if (Resource->ActiveEntries == 0)
|
||
{
|
||
/* Nobody owns it, so let's take control */
|
||
ASSERT(Resource->ActiveEntries == 0);
|
||
ASSERT(Resource->ActiveCount == 0);
|
||
Resource->ActiveCount = 1;
|
||
Resource->ActiveEntries = 1;
|
||
Resource->OwnerEntry.OwnerThread = Thread;
|
||
Resource->OwnerEntry.OwnerCount = 1;
|
||
|
||
/* Release the lock and return */
|
||
ExReleaseResourceLock(Resource, &LockHandle);
|
||
return TRUE;
|
||
}
|
||
|
||
/* Check if it's exclusively owned */
|
||
if (IsOwnedExclusive(Resource))
|
||
{
|
||
/* Check if we own it */
|
||
if (Resource->OwnerEntry.OwnerThread == Thread)
|
||
{
|
||
/* Increase the owning count */
|
||
Resource->OwnerEntry.OwnerCount++;
|
||
|
||
/* Release the lock and return */
|
||
ExReleaseResourceLock(Resource, &LockHandle);
|
||
return TRUE;
|
||
}
|
||
|
||
/* Find a free entry */
|
||
Owner = ExpFindFreeEntry(Resource, &LockHandle);
|
||
if (!Owner) goto TryAcquire;
|
||
}
|
||
else
|
||
{
|
||
/* Resource is shared, find who owns it */
|
||
Owner = ExpFindEntryForThread(Resource, Thread, &LockHandle, FALSE);
|
||
if (!Owner) goto TryAcquire;
|
||
|
||
/* Is it us? */
|
||
if (Owner->OwnerThread == Thread)
|
||
{
|
||
/* Increase acquire count and return */
|
||
Owner->OwnerCount++;
|
||
ASSERT(Owner->OwnerCount != 0);
|
||
|
||
/* Release the lock and return */
|
||
ExReleaseResourceLock(Resource, &LockHandle);
|
||
return TRUE;
|
||
}
|
||
|
||
/* Acquire it */
|
||
Owner->OwnerThread = Thread;
|
||
Owner->OwnerCount = 1;
|
||
|
||
/* Check how many active entries we had */
|
||
if (Resource->ActiveEntries == 0)
|
||
{
|
||
/* Set initial counts */
|
||
ASSERT(Resource->ActiveCount == 0);
|
||
Resource->ActiveEntries = 1;
|
||
Resource->ActiveCount = 1;
|
||
}
|
||
else
|
||
{
|
||
/* Increase active entries */
|
||
ASSERT(Resource->ActiveCount == 1);
|
||
Resource->ActiveEntries++;
|
||
}
|
||
|
||
/* Release the lock and return */
|
||
ExReleaseResourceLock(Resource, &LockHandle);
|
||
return TRUE;
|
||
}
|
||
|
||
/* If we got here, then we need to wait. Are we allowed? */
|
||
if (!Wait)
|
||
{
|
||
/* Release the lock and return */
|
||
ExReleaseResourceLock(Resource, &LockHandle);
|
||
return FALSE;
|
||
}
|
||
|
||
/* Check if we have a shared waiters semaphore */
|
||
if (!Resource->SharedWaiters)
|
||
{
|
||
/* Allocate it and try another acquire */
|
||
ExpAllocateSharedWaiterSemaphore(Resource, &LockHandle);
|
||
goto TryAcquire;
|
||
}
|
||
|
||
/* Now wait for the resource */
|
||
Owner->OwnerThread = Thread;
|
||
Owner->OwnerCount = 1;
|
||
Resource->NumberOfSharedWaiters++;
|
||
|
||
/* Release the lock and return */
|
||
ExReleaseResourceLock(Resource, &LockHandle);
|
||
ExpWaitForResource(Resource, Resource->SharedWaiters);
|
||
return TRUE;
|
||
}
|
||
|
||
/*++
|
||
* @name ExAcquireSharedWaitForExclusive
|
||
* @implemented NT4
|
||
*
|
||
* The ExAcquireSharedWaitForExclusive routine acquires the given resource
|
||
* for shared access if shared access can be granted and there are no
|
||
* exclusive waiters.
|
||
*
|
||
* @param Resource
|
||
* Pointer to the resource to acquire.
|
||
*
|
||
* @param Wait
|
||
* Specifies the routine's behavior whenever the resource cannot be
|
||
* acquired immediately.
|
||
*
|
||
* @return TRUE if the resource is acquired. FALSE if the input Wait is FALSE
|
||
* and exclusive access cannot be granted immediately.
|
||
*
|
||
* @remarks The caller can release the resource by calling either
|
||
* ExReleaseResourceLite or ExReleaseResourceForThreadLite.
|
||
*
|
||
* Normal kernel APC delivery must be disabled before calling this
|
||
* routine. Disable normal kernel APC delivery by calling
|
||
* KeEnterCriticalRegion. Delivery must remain disabled until the
|
||
* resource is released, at which point it can be reenabled by calling
|
||
* KeLeaveCriticalRegion.
|
||
*
|
||
* Callers of ExAcquireResourceExclusiveLite must be running at IRQL <
|
||
* DISPATCH_LEVEL.
|
||
*
|
||
*--*/
|
||
BOOLEAN
|
||
NTAPI
|
||
ExAcquireSharedWaitForExclusive(IN PERESOURCE Resource,
|
||
IN BOOLEAN Wait)
|
||
{
|
||
KLOCK_QUEUE_HANDLE LockHandle;
|
||
ERESOURCE_THREAD Thread;
|
||
POWNER_ENTRY Owner;
|
||
|
||
/* Get the thread */
|
||
Thread = ExGetCurrentResourceThread();
|
||
|
||
/* Sanity check and validation */
|
||
ASSERT(KeIsExecutingDpc() == FALSE);
|
||
ExpVerifyResource(Resource);
|
||
|
||
/* Acquire the lock */
|
||
ExAcquireResourceLock(Resource, &LockHandle);
|
||
|
||
/* See if nobody owns us */
|
||
TryAcquire:
|
||
if (!Resource->ActiveEntries)
|
||
{
|
||
/* Nobody owns it, so let's take control */
|
||
ASSERT(Resource->ActiveEntries == 0);
|
||
ASSERT(Resource->ActiveCount == 0);
|
||
Resource->ActiveCount = 1;
|
||
Resource->ActiveEntries = 1;
|
||
Resource->OwnerEntry.OwnerThread = Thread;
|
||
Resource->OwnerEntry.OwnerCount = 1;
|
||
|
||
/* Release the lock and return */
|
||
ExReleaseResourceLock(Resource, &LockHandle);
|
||
return TRUE;
|
||
}
|
||
|
||
/* Check if it's exclusively owned */
|
||
if (IsOwnedExclusive(Resource))
|
||
{
|
||
/* Check if we own it */
|
||
if (Resource->OwnerEntry.OwnerThread == Thread)
|
||
{
|
||
/* Increase the owning count */
|
||
Resource->OwnerEntry.OwnerCount++;
|
||
|
||
/* Release the lock and return */
|
||
ExReleaseResourceLock(Resource, &LockHandle);
|
||
return TRUE;
|
||
}
|
||
|
||
/* Find a free entry */
|
||
Owner = ExpFindFreeEntry(Resource, &LockHandle);
|
||
if (!Owner) goto TryAcquire;
|
||
}
|
||
else
|
||
{
|
||
/* Try to find if there are exclusive waiters */
|
||
if (IsExclusiveWaiting(Resource))
|
||
{
|
||
/* We have to wait for the exclusive waiter to be done */
|
||
if (!Wait)
|
||
{
|
||
/* So bail out if we're not allowed */
|
||
ExReleaseResourceLock(Resource, &LockHandle);
|
||
return FALSE;
|
||
}
|
||
|
||
/* Check if we have a shared waiters semaphore */
|
||
if (!Resource->SharedWaiters)
|
||
{
|
||
/* Allocate one and try again */
|
||
ExpAllocateSharedWaiterSemaphore(Resource, &LockHandle);
|
||
goto TryAcquire;
|
||
}
|
||
|
||
/* Now wait for the resource */
|
||
Resource->NumberOfSharedWaiters++;
|
||
ExReleaseResourceLock(Resource, &LockHandle);
|
||
ExpWaitForResource(Resource, Resource->SharedWaiters);
|
||
|
||
/* Get the lock back */
|
||
ExAcquireResourceLock(Resource, &LockHandle);
|
||
|
||
/* Find who owns it now */
|
||
while (!(Owner = ExpFindEntryForThread(Resource, Thread, &LockHandle, TRUE)));
|
||
|
||
/* Sanity checks */
|
||
ASSERT(IsOwnedExclusive(Resource) == FALSE);
|
||
ASSERT(Resource->ActiveEntries > 0);
|
||
ASSERT(Owner->OwnerThread != Thread);
|
||
|
||
/* Take control */
|
||
Owner->OwnerThread = Thread;
|
||
Owner->OwnerCount = 1;
|
||
|
||
/* Release the lock and return */
|
||
ExReleaseResourceLock(Resource, &LockHandle);
|
||
return TRUE;
|
||
}
|
||
else
|
||
{
|
||
/* Resource is shared, find who owns it */
|
||
Owner = ExpFindEntryForThread(Resource, Thread, &LockHandle, FALSE);
|
||
if (!Owner) goto TryAcquire;
|
||
|
||
/* Is it us? */
|
||
if (Owner->OwnerThread == Thread)
|
||
{
|
||
/* Increase acquire count and return */
|
||
Owner->OwnerCount++;
|
||
ASSERT(Owner->OwnerCount != 0);
|
||
|
||
/* Release the lock and return */
|
||
ExReleaseResourceLock(Resource, &LockHandle);
|
||
return TRUE;
|
||
}
|
||
|
||
/* No exclusive waiters, so acquire it */
|
||
Owner->OwnerThread = Thread;
|
||
Owner->OwnerCount = 1;
|
||
|
||
/* Check how many active entries we had */
|
||
if (Resource->ActiveEntries == 0)
|
||
{
|
||
/* Set initial counts */
|
||
ASSERT(Resource->ActiveCount == 0);
|
||
Resource->ActiveEntries = 1;
|
||
Resource->ActiveCount = 1;
|
||
}
|
||
else
|
||
{
|
||
/* Increase active entries */
|
||
ASSERT(Resource->ActiveCount == 1);
|
||
Resource->ActiveEntries++;
|
||
}
|
||
|
||
/* Release the lock and return */
|
||
ExReleaseResourceLock(Resource, &LockHandle);
|
||
return TRUE;
|
||
}
|
||
}
|
||
|
||
/* We have to wait for the exclusive waiter to be done */
|
||
if (!Wait)
|
||
{
|
||
/* So bail out if we're not allowed */
|
||
ExReleaseResourceLock(Resource, &LockHandle);
|
||
return FALSE;
|
||
}
|
||
|
||
/* Check if we have a shared waiters semaphore */
|
||
if (!Resource->SharedWaiters)
|
||
{
|
||
/* Allocate one and try again */
|
||
ExpAllocateSharedWaiterSemaphore(Resource,&LockHandle);
|
||
goto TryAcquire;
|
||
}
|
||
|
||
/* Take control */
|
||
Owner->OwnerThread = Thread;
|
||
Owner->OwnerCount = 1;
|
||
Resource->NumberOfSharedWaiters++;
|
||
|
||
/* Release the lock and return */
|
||
ExReleaseResourceLock(Resource, &LockHandle);
|
||
ExpWaitForResource(Resource, Resource->SharedWaiters);
|
||
return TRUE;
|
||
}
|
||
|
||
/*++
|
||
* @name ExConvertExclusiveToSharedLite
|
||
* @implemented NT4
|
||
*
|
||
* The ExConvertExclusiveToSharedLite routine converts an exclusively
|
||
* acquired resource into a resource that can be acquired shared.
|
||
*
|
||
* @param Resource
|
||
* Pointer to the resource to convert.
|
||
*
|
||
* @return None.
|
||
*
|
||
* @remarks Callers of ExConvertExclusiveToSharedLite must be running at IRQL <
|
||
* DISPATCH_LEVEL.
|
||
*
|
||
*--*/
|
||
VOID
|
||
NTAPI
|
||
ExConvertExclusiveToSharedLite(IN PERESOURCE Resource)
|
||
{
|
||
ULONG OldWaiters;
|
||
KLOCK_QUEUE_HANDLE LockHandle;
|
||
|
||
/* Sanity checks */
|
||
ASSERT(KeIsExecutingDpc() == FALSE);
|
||
ExpVerifyResource(Resource);
|
||
ASSERT(IsOwnedExclusive(Resource));
|
||
ASSERT(Resource->OwnerEntry.OwnerThread == (ERESOURCE_THREAD)PsGetCurrentThread());
|
||
|
||
/* Lock the resource */
|
||
ExAcquireResourceLock(Resource, &LockHandle);
|
||
|
||
/* Erase the exclusive flag */
|
||
Resource->Flag &= ~ResourceOwnedExclusive;
|
||
|
||
/* Check if we have shared waiters */
|
||
if (IsSharedWaiting(Resource))
|
||
{
|
||
/* Make the waiters active owners */
|
||
OldWaiters = Resource->NumberOfSharedWaiters;
|
||
Resource->ActiveEntries += OldWaiters;
|
||
Resource->NumberOfSharedWaiters = 0;
|
||
|
||
/* Release lock and wake the waiters */
|
||
ExReleaseResourceLock(Resource, &LockHandle);
|
||
KeReleaseSemaphore(Resource->SharedWaiters, 0, OldWaiters, FALSE);
|
||
}
|
||
else
|
||
{
|
||
/* Release lock */
|
||
ExReleaseResourceLock(Resource, &LockHandle);
|
||
}
|
||
}
|
||
|
||
/*++
|
||
* @name ExDeleteResourceLite
|
||
* @implemented NT4
|
||
*
|
||
* The ExConvertExclusiveToSharedLite routine deletes a given resource
|
||
* from the system<65>s resource list.
|
||
*
|
||
* @param Resource
|
||
* Pointer to the resource to delete.
|
||
*
|
||
* @return STATUS_SUCCESS if the resource was deleted.
|
||
*
|
||
* @remarks Callers of ExDeleteResourceLite must be running at IRQL <
|
||
* DISPATCH_LEVEL.
|
||
*
|
||
*--*/
|
||
NTSTATUS
|
||
NTAPI
|
||
ExDeleteResourceLite(IN PERESOURCE Resource)
|
||
{
|
||
KLOCK_QUEUE_HANDLE LockHandle;
|
||
|
||
/* Sanity checks */
|
||
ASSERT(IsSharedWaiting(Resource) == FALSE);
|
||
ASSERT(IsExclusiveWaiting(Resource) == FALSE);
|
||
ASSERT(KeIsExecutingDpc() == FALSE);
|
||
ExpVerifyResource(Resource);
|
||
|
||
/* Lock the resource */
|
||
KeAcquireInStackQueuedSpinLock(&ExpResourceSpinLock, &LockHandle);
|
||
|
||
/* Remove the resource */
|
||
RemoveEntryList(&Resource->SystemResourcesList);
|
||
|
||
/* Release the lock */
|
||
KeReleaseInStackQueuedSpinLock(&LockHandle);
|
||
|
||
/* Free every structure */
|
||
if (Resource->OwnerTable) ExFreePoolWithTag(Resource->OwnerTable, TAG_RESOURCE_TABLE);
|
||
if (Resource->SharedWaiters) ExFreePoolWithTag(Resource->SharedWaiters, TAG_RESOURCE_SEMAPHORE);
|
||
if (Resource->ExclusiveWaiters) ExFreePoolWithTag(Resource->ExclusiveWaiters, TAG_RESOURCE_EVENT);
|
||
|
||
/* Return success */
|
||
return STATUS_SUCCESS;
|
||
}
|
||
|
||
/*++
|
||
* @name ExDisableResourceBoostLite
|
||
* @implemented NT4
|
||
*
|
||
* The ExDisableResourceBoostLite routine disables thread boosting for
|
||
* the given resource.
|
||
*
|
||
* @param Resource
|
||
* Pointer to the resource whose thread boosting will be disabled.
|
||
*
|
||
* @return None.
|
||
*
|
||
* @remarks None.
|
||
*
|
||
*--*/
|
||
VOID
|
||
NTAPI
|
||
ExDisableResourceBoostLite(IN PERESOURCE Resource)
|
||
{
|
||
KLOCK_QUEUE_HANDLE LockHandle;
|
||
|
||
/* Sanity check */
|
||
ExpVerifyResource(Resource);
|
||
|
||
/* Lock the resource */
|
||
ExAcquireResourceLock(Resource, &LockHandle);
|
||
|
||
/* Remove the flag */
|
||
Resource->Flag |= ResourceHasDisabledPriorityBoost;
|
||
|
||
/* Release the lock */
|
||
ExReleaseResourceLock(Resource, &LockHandle);
|
||
}
|
||
|
||
/*++
|
||
* @name ExGetExclusiveWaiterCount
|
||
* @implemented NT4
|
||
*
|
||
* The ExGetExclusiveWaiterCount routine returns the number of exclusive
|
||
* waiters for the given resource.
|
||
*
|
||
* @param Resource
|
||
* Pointer to the resource to check.
|
||
*
|
||
* @return The number of exclusive waiters.
|
||
*
|
||
* @remarks None.
|
||
*
|
||
*--*/
|
||
ULONG
|
||
NTAPI
|
||
ExGetExclusiveWaiterCount(IN PERESOURCE Resource)
|
||
{
|
||
/* Return the count */
|
||
return Resource->NumberOfExclusiveWaiters;
|
||
}
|
||
|
||
/*++
|
||
* @name ExGetSharedWaiterCount
|
||
* @implemented NT4
|
||
*
|
||
* The ExGetSharedWaiterCount routine returns the number of shared
|
||
* waiters for the given resource.
|
||
*
|
||
* @param Resource
|
||
* Pointer to the resource to check.
|
||
*
|
||
* @return The number of shared waiters.
|
||
*
|
||
* @remarks None.
|
||
*
|
||
*--*/
|
||
ULONG
|
||
NTAPI
|
||
ExGetSharedWaiterCount(IN PERESOURCE Resource)
|
||
{
|
||
/* Return the count */
|
||
return Resource->NumberOfSharedWaiters;
|
||
}
|
||
|
||
/*++
|
||
* @name ExInitializeResourceLite
|
||
* @implemented NT4
|
||
*
|
||
* The ExInitializeResourceLite routine initializes a resource variable.
|
||
*
|
||
* @param Resource
|
||
* Pointer to the resource to check.
|
||
*
|
||
* @return STATUS_SUCCESS.
|
||
*
|
||
* @remarks The storage for ERESOURCE must not be allocated from paged pool.
|
||
*
|
||
* The storage must be 8-byte aligned.
|
||
*
|
||
*--*/
|
||
NTSTATUS
|
||
NTAPI
|
||
ExInitializeResourceLite(IN PERESOURCE Resource)
|
||
{
|
||
KLOCK_QUEUE_HANDLE LockHandle;
|
||
|
||
/* Clear the structure */
|
||
RtlZeroMemory(Resource, sizeof(ERESOURCE));
|
||
|
||
/* Initialize the lock */
|
||
KeInitializeSpinLock(&Resource->SpinLock);
|
||
|
||
/* Add it into the system list */
|
||
KeAcquireInStackQueuedSpinLock(&ExpResourceSpinLock, &LockHandle);
|
||
InsertTailList(&ExpSystemResourcesList, &Resource->SystemResourcesList);
|
||
KeReleaseInStackQueuedSpinLock(&LockHandle);
|
||
|
||
/* Return success */
|
||
return STATUS_SUCCESS;
|
||
}
|
||
|
||
/*++
|
||
* @name ExIsResourceAcquiredExclusiveLite
|
||
* @implemented NT4
|
||
*
|
||
* The ExIsResourceAcquiredExclusiveLite routine returns whether the
|
||
* current thread has exclusive access to a given resource.
|
||
*
|
||
* @param Resource
|
||
* Pointer to the resource to check.
|
||
*
|
||
* @return TRUE if the caller already has exclusive access to the given resource.
|
||
*
|
||
* @remarks Callers of ExIsResourceAcquiredExclusiveLite must be running at
|
||
* IRQL <= DISPATCH_LEVEL.
|
||
*
|
||
*--*/
|
||
BOOLEAN
|
||
NTAPI
|
||
ExIsResourceAcquiredExclusiveLite(IN PERESOURCE Resource)
|
||
{
|
||
BOOLEAN IsAcquired = FALSE;
|
||
|
||
/* Sanity check */
|
||
ExpVerifyResource(Resource);
|
||
|
||
/* Check if it's exclusively acquired */
|
||
if ((IsOwnedExclusive(Resource)) &&
|
||
(Resource->OwnerEntry.OwnerThread == ExGetCurrentResourceThread()))
|
||
{
|
||
/* It is acquired */
|
||
IsAcquired = TRUE;
|
||
}
|
||
|
||
/* Return if it's acquired */
|
||
return IsAcquired;
|
||
}
|
||
|
||
/*++
|
||
* @name ExIsResourceAcquiredSharedLite
|
||
* @implemented NT4
|
||
*
|
||
* The ExIsResourceAcquiredSharedLite routine returns whether the
|
||
* current thread has has access (either shared or exclusive) to a
|
||
* given resource.
|
||
*
|
||
* @param Resource
|
||
* Pointer to the resource to check.
|
||
*
|
||
* @return Number of times the caller has acquired the given resource for
|
||
* shared or exclusive access.
|
||
*
|
||
* @remarks Callers of ExIsResourceAcquiredExclusiveLite must be running at
|
||
* IRQL <= DISPATCH_LEVEL.
|
||
*
|
||
*--*/
|
||
ULONG
|
||
NTAPI
|
||
ExIsResourceAcquiredSharedLite(IN PERESOURCE Resource)
|
||
{
|
||
ERESOURCE_THREAD Thread;
|
||
ULONG i, Size;
|
||
ULONG Count = 0;
|
||
KLOCK_QUEUE_HANDLE LockHandle;
|
||
POWNER_ENTRY Owner;
|
||
|
||
/* Sanity check */
|
||
ExpVerifyResource(Resource);
|
||
|
||
/* Check if nobody owns us */
|
||
if (!Resource->ActiveEntries) return 0;
|
||
|
||
/* Get the thread */
|
||
Thread = ExGetCurrentResourceThread();
|
||
|
||
/* Check if we are in the thread list */
|
||
if (Resource->OwnerEntry.OwnerThread == Thread)
|
||
{
|
||
/* Found it, return count */
|
||
Count = Resource->OwnerEntry.OwnerCount;
|
||
}
|
||
else
|
||
{
|
||
/* We can't own an exclusive resource at this point */
|
||
if (IsOwnedExclusive(Resource)) return 0;
|
||
|
||
/* Lock the resource */
|
||
ExAcquireResourceLock(Resource, &LockHandle);
|
||
|
||
/* Not in the list, do a full table look up */
|
||
Owner = Resource->OwnerTable;
|
||
if (Owner)
|
||
{
|
||
/* Get the resource index */
|
||
i = ((PKTHREAD)Thread)->ResourceIndex;
|
||
Size = Owner->TableSize;
|
||
|
||
/* Check if the index is valid and check if we don't match */
|
||
if ((i >= Size) || (Owner[i].OwnerThread != Thread))
|
||
{
|
||
/* Sh*t! We need to do a full search */
|
||
for (i = 1; i < Size; i++)
|
||
{
|
||
/* Move to next owner */
|
||
Owner++;
|
||
|
||
/* Try to find a match */
|
||
if (Owner->OwnerThread == Thread)
|
||
{
|
||
/* Finally! */
|
||
Count = Owner->OwnerCount;
|
||
break;
|
||
}
|
||
}
|
||
}
|
||
else
|
||
{
|
||
/* We found the match directlry */
|
||
Count = Owner[i].OwnerCount;
|
||
}
|
||
}
|
||
|
||
/* Release the lock */
|
||
ExReleaseResourceLock(Resource, &LockHandle);
|
||
}
|
||
|
||
/* Return count */
|
||
return Count;
|
||
}
|
||
|
||
/*++
|
||
* @name ExReinitializeResourceLite
|
||
* @implemented NT4
|
||
*
|
||
* The ExReinitializeResourceLite routine routine reinitializes
|
||
* an existing resource variable.
|
||
*
|
||
* @param Resource
|
||
* Pointer to the resource to be reinitialized.
|
||
*
|
||
* @return STATUS_SUCCESS.
|
||
*
|
||
* @remarks With a single call to ExReinitializeResource, a driver writer can
|
||
* replace three calls: one to ExDeleteResourceLite, another to
|
||
* ExAllocatePool, and a third to ExInitializeResourceLite. As
|
||
* contention for a resource variable increases, memory is dynamically
|
||
* allocated and attached to the resource in order to track this
|
||
* contention. As an optimization, ExReinitializeResourceLite retains
|
||
* and zeroes this previously allocated memory.
|
||
*
|
||
* Callers of ExReinitializeResourceLite must be running at
|
||
* IRQL <= DISPATCH_LEVEL.
|
||
*
|
||
*--*/
|
||
NTSTATUS
|
||
NTAPI
|
||
ExReinitializeResourceLite(IN PERESOURCE Resource)
|
||
{
|
||
PKEVENT Event;
|
||
PKSEMAPHORE Semaphore;
|
||
ULONG i, Size;
|
||
POWNER_ENTRY Owner;
|
||
|
||
/* Get the owner table */
|
||
Owner = Resource->OwnerTable;
|
||
if (Owner)
|
||
{
|
||
/* Get the size and loop it */
|
||
Size = Owner->TableSize;
|
||
for (i = 0; i < Size; i++)
|
||
{
|
||
/* Zero the table */
|
||
Owner[i].OwnerThread = 0;
|
||
Owner[i].OwnerCount = 0;
|
||
}
|
||
}
|
||
|
||
/* Zero the flags and count */
|
||
Resource->Flag = 0;
|
||
Resource->ActiveCount = 0;
|
||
Resource->ActiveEntries = 0;
|
||
|
||
/* Reset the semaphore */
|
||
Semaphore = Resource->SharedWaiters;
|
||
if (Semaphore) KeInitializeSemaphore(Semaphore, 0, MAXLONG);
|
||
|
||
/* Reset the event */
|
||
Event = Resource->ExclusiveWaiters;
|
||
if (Event) KeInitializeEvent(Event, SynchronizationEvent, FALSE);
|
||
|
||
/* Clear the resource data */
|
||
Resource->OwnerEntry.OwnerThread = 0;
|
||
Resource->OwnerEntry.OwnerCount = 0;
|
||
Resource->ContentionCount = 0;
|
||
Resource->NumberOfSharedWaiters = 0;
|
||
Resource->NumberOfExclusiveWaiters = 0;
|
||
return STATUS_SUCCESS;
|
||
}
|
||
|
||
/*++
|
||
* @name ExReleaseResourceLite
|
||
* @implemented NT4
|
||
*
|
||
* The ExReleaseResourceLite routine routine releases
|
||
* a specified executive resource owned by the current thread.
|
||
*
|
||
* @param Resource
|
||
* Pointer to the resource to be released.
|
||
*
|
||
* @return None.
|
||
*
|
||
* @remarks Callers of ExReleaseResourceLite must be running at
|
||
* IRQL <= DISPATCH_LEVEL.
|
||
*
|
||
*--*/
|
||
VOID
|
||
FASTCALL
|
||
ExReleaseResourceLite(IN PERESOURCE Resource)
|
||
{
|
||
/* Just call the For-Thread function */
|
||
ExReleaseResourceForThreadLite(Resource, ExGetCurrentResourceThread());
|
||
}
|
||
|
||
/*++
|
||
* @name ExReleaseResourceForThreadLite
|
||
* @implemented NT4
|
||
*
|
||
* The ExReleaseResourceForThreadLite routine routine releases
|
||
* the input resource of the indicated thread.
|
||
*
|
||
* @param Resource
|
||
* Pointer to the resource to be released.
|
||
*
|
||
* @param Thread
|
||
* Identifies the thread that originally acquired the resource.
|
||
*
|
||
* @return None.
|
||
*
|
||
* @remarks Callers of ExReleaseResourceForThreadLite must be running at
|
||
* IRQL <= DISPATCH_LEVEL.
|
||
*
|
||
*--*/
|
||
VOID
|
||
NTAPI
|
||
ExReleaseResourceForThreadLite(IN PERESOURCE Resource,
|
||
IN ERESOURCE_THREAD Thread)
|
||
{
|
||
ULONG i;
|
||
ULONG Count;
|
||
KLOCK_QUEUE_HANDLE LockHandle;
|
||
POWNER_ENTRY Owner, Limit;
|
||
ASSERT(Thread != 0);
|
||
|
||
/* Get the thread and lock the resource */
|
||
ExAcquireResourceLock(Resource, &LockHandle);
|
||
|
||
/* Sanity checks */
|
||
ExpVerifyResource(Resource);
|
||
ExpCheckForApcsDisabled(LockHandle.OldIrql, Resource, KeGetCurrentThread());
|
||
|
||
/* Check if it's exclusively owned */
|
||
if (IsOwnedExclusive(Resource))
|
||
{
|
||
/* Decrement owner count and check if we're done */
|
||
ASSERT(Resource->OwnerEntry.OwnerThread == Thread);
|
||
if (--Resource->OwnerEntry.OwnerCount)
|
||
{
|
||
/* Done, release lock! */
|
||
ExReleaseResourceLock(Resource, &LockHandle);
|
||
return;
|
||
}
|
||
|
||
/* Clear the owner */
|
||
Resource->OwnerEntry.OwnerThread = 0;
|
||
|
||
/* Decrement the number of active entries */
|
||
ASSERT(Resource->ActiveEntries == 1);
|
||
Resource->ActiveEntries--;
|
||
|
||
/* Check if there are shared waiters */
|
||
if (IsSharedWaiting(Resource))
|
||
{
|
||
/* Remove the exclusive flag */
|
||
Resource->Flag &= ~ResourceOwnedExclusive;
|
||
|
||
/* Give ownage to another thread */
|
||
Count = Resource->NumberOfSharedWaiters;
|
||
Resource->ActiveEntries = Count;
|
||
Resource->NumberOfSharedWaiters = 0;
|
||
|
||
/* Release lock and let someone else have it */
|
||
ASSERT(Resource->ActiveCount == 1);
|
||
ExReleaseResourceLock(Resource, &LockHandle);
|
||
KeReleaseSemaphore(Resource->SharedWaiters, 0, Count, FALSE);
|
||
return;
|
||
}
|
||
else if (IsExclusiveWaiting(Resource))
|
||
{
|
||
/* Give exclusive access */
|
||
Resource->OwnerEntry.OwnerThread = 1;
|
||
Resource->OwnerEntry.OwnerCount = 1;
|
||
Resource->ActiveEntries = 1;
|
||
Resource->NumberOfExclusiveWaiters--;
|
||
|
||
/* Release the lock and give it away */
|
||
ASSERT(Resource->ActiveCount == 1);
|
||
ExReleaseResourceLock(Resource, &LockHandle);
|
||
KeSetEventBoostPriority(Resource->ExclusiveWaiters,
|
||
(PKTHREAD*)&Resource->OwnerEntry.OwnerThread);
|
||
return;
|
||
}
|
||
|
||
/* Remove the exclusive flag */
|
||
Resource->Flag &= ~ResourceOwnedExclusive;
|
||
Resource->ActiveCount = 0;
|
||
}
|
||
else
|
||
{
|
||
/* Check if we are in the thread list */
|
||
if (Resource->OwnerEntry.OwnerThread == Thread)
|
||
{
|
||
/* Found it, get owner */
|
||
Owner = &Resource->OwnerEntry;
|
||
}
|
||
else
|
||
{
|
||
/* Assume no valid index */
|
||
i = 1;
|
||
|
||
/* If we got a valid pointer, try to get the resource index */
|
||
if (!((ULONG)Thread & 3)) i = ((PKTHREAD)Thread)->ResourceIndex;
|
||
|
||
/* Do a table lookup */
|
||
Owner = Resource->OwnerTable;
|
||
ASSERT(Owner != NULL);
|
||
|
||
/* Check if we're out of the size and don't match */
|
||
if ((i >= Owner->TableSize) || (Owner[i].OwnerThread != Thread))
|
||
{
|
||
/* Get the last entry */
|
||
Limit = &Owner[Owner->TableSize];
|
||
for (;;)
|
||
{
|
||
/* Move to the next entry */
|
||
Owner++;
|
||
|
||
/* Make sure we're not out of bounds */
|
||
if (Owner >= Limit)
|
||
{
|
||
/* Bugcheck, nobody owns us */
|
||
KeBugCheckEx(RESOURCE_NOT_OWNED,
|
||
(ULONG_PTR)Resource,
|
||
(ULONG_PTR)Thread,
|
||
(ULONG_PTR)Resource->OwnerTable,
|
||
(ULONG_PTR)3);
|
||
}
|
||
|
||
/* Check for a match */
|
||
if (Owner->OwnerThread == Thread) break;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
/* Get the entry directly */
|
||
Owner = &Owner[i];
|
||
}
|
||
}
|
||
|
||
/* Sanity checks */
|
||
ASSERT(Owner->OwnerThread == Thread);
|
||
ASSERT(Owner->OwnerCount > 0);
|
||
|
||
/* Check if we are the last owner */
|
||
if (--Owner->OwnerCount)
|
||
{
|
||
/* There are other owners, release lock */
|
||
ExReleaseResourceLock(Resource, &LockHandle);
|
||
return;
|
||
}
|
||
|
||
/* Clear owner */
|
||
Owner->OwnerThread = 0;
|
||
|
||
/* See if the resource isn't being owned anymore */
|
||
ASSERT(Resource->ActiveEntries > 0);
|
||
if (!(--Resource->ActiveEntries))
|
||
{
|
||
/* Check if there's an exclusive waiter */
|
||
if (IsExclusiveWaiting(Resource))
|
||
{
|
||
/* Give exclusive access */
|
||
Resource->Flag |= ResourceOwnedExclusive;
|
||
Resource->OwnerEntry.OwnerThread = 1;
|
||
Resource->OwnerEntry.OwnerCount = 1;
|
||
Resource->ActiveEntries = 1;
|
||
Resource->NumberOfExclusiveWaiters--;
|
||
|
||
/* Release the lock and give it away */
|
||
ASSERT(Resource->ActiveCount == 1);
|
||
ExReleaseResourceLock(Resource, &LockHandle);
|
||
KeSetEventBoostPriority(Resource->ExclusiveWaiters,
|
||
(PKTHREAD*)&Resource->OwnerEntry.OwnerThread);
|
||
return;
|
||
}
|
||
|
||
/* Clear the active count */
|
||
Resource->ActiveCount = 0;
|
||
}
|
||
}
|
||
|
||
/* Release lock */
|
||
ExReleaseResourceLock(Resource, &LockHandle);
|
||
}
|
||
|
||
/*++
|
||
* @name ExSetResourceOwnerPointer
|
||
* @implemented NT4
|
||
*
|
||
* The ExSetResourceOwnerPointer routine routine sets the owner thread
|
||
* thread pointer for an executive resource.
|
||
*
|
||
* @param Resource
|
||
* Pointer to the resource whose owner to change.
|
||
*
|
||
* @param OwnerPointer
|
||
* Pointer to an owner thread pointer of type ERESOURCE_THREAD.
|
||
*
|
||
* @return None.
|
||
*
|
||
* @remarks ExSetResourceOwnerPointer, used in conjunction with
|
||
* ExReleaseResourceForThreadLite, provides a means for one thread
|
||
* (acting as an resource manager thread) to acquire and release
|
||
* resources for use by another thread (acting as a resource user
|
||
* thread).
|
||
*
|
||
* After calling ExSetResourceOwnerPointer for a specific resource,
|
||
* the only other routine that can be called for that resource is
|
||
* ExReleaseResourceForThreadLite.
|
||
*
|
||
* Callers of ExSetResourceOwnerPointer must be running at
|
||
* IRQL <= DISPATCH_LEVEL.
|
||
*
|
||
*--*/
|
||
VOID
|
||
NTAPI
|
||
ExSetResourceOwnerPointer(IN PERESOURCE Resource,
|
||
IN PVOID OwnerPointer)
|
||
{
|
||
ERESOURCE_THREAD Thread;
|
||
KLOCK_QUEUE_HANDLE LockHandle;
|
||
POWNER_ENTRY Owner, ThisOwner;
|
||
|
||
/* Sanity check */
|
||
ASSERT((OwnerPointer != 0) && (((ULONG_PTR)OwnerPointer & 3) == 3));
|
||
|
||
/* Get the thread */
|
||
Thread = ExGetCurrentResourceThread();
|
||
|
||
/* Sanity check */
|
||
ExpVerifyResource(Resource);
|
||
|
||
/* Lock the resource */
|
||
ExAcquireResourceLock(Resource, &LockHandle);
|
||
|
||
/* Check if it's exclusive */
|
||
if (IsOwnedExclusive(Resource))
|
||
{
|
||
/* If it's exclusive, set the first entry no matter what */
|
||
ASSERT(Resource->OwnerEntry.OwnerThread == Thread);
|
||
ASSERT(Resource->OwnerEntry.OwnerCount > 0);
|
||
Resource->OwnerEntry.OwnerThread = (ULONG_PTR)OwnerPointer;
|
||
}
|
||
else
|
||
{
|
||
/* Set the thread in both entries */
|
||
ThisOwner = ExpFindEntryForThread(Resource,
|
||
(ERESOURCE_THREAD)OwnerPointer,
|
||
0,
|
||
FALSE);
|
||
Owner = ExpFindEntryForThread(Resource, Thread, 0, FALSE);
|
||
if (!Owner)
|
||
{
|
||
/* Nobody owns it, crash */
|
||
KeBugCheckEx(RESOURCE_NOT_OWNED,
|
||
(ULONG_PTR)Resource,
|
||
Thread,
|
||
(ULONG_PTR)Resource->OwnerTable,
|
||
3);
|
||
}
|
||
|
||
/* Set if we are the owner */
|
||
if (ThisOwner)
|
||
{
|
||
/* Update data */
|
||
ThisOwner->OwnerCount += Owner->OwnerCount;
|
||
Owner->OwnerCount = 0;
|
||
Owner->OwnerThread = 0;
|
||
ASSERT(Resource->ActiveEntries >= 2);
|
||
Resource->ActiveEntries--;
|
||
}
|
||
else
|
||
{
|
||
/* Update the owner entry instead */
|
||
Owner->OwnerThread = (ERESOURCE_THREAD)OwnerPointer;
|
||
}
|
||
}
|
||
|
||
/* Release the resource */
|
||
ExReleaseResourceLock(Resource, &LockHandle);
|
||
}
|
||
|
||
/*++
|
||
* @name ExTryToAcquireResourceExclusiveLite
|
||
* @implemented NT4
|
||
*
|
||
* The ExTryToAcquireResourceExclusiveLite routine routine attemps to
|
||
* acquire the given resource for exclusive access.
|
||
*
|
||
* @param Resource
|
||
* Pointer to the resource to be acquired.
|
||
*
|
||
* @return TRUE if the given resource has been acquired for the caller.
|
||
*
|
||
* @remarks Callers of ExTryToAcquireResourceExclusiveLite must be running at
|
||
* IRQL < DISPATCH_LEVEL.
|
||
*
|
||
*--*/
|
||
BOOLEAN
|
||
NTAPI
|
||
ExTryToAcquireResourceExclusiveLite(IN PERESOURCE Resource)
|
||
{
|
||
ERESOURCE_THREAD Thread;
|
||
KLOCK_QUEUE_HANDLE LockHandle;
|
||
BOOLEAN Acquired = FALSE;
|
||
|
||
/* Sanity check */
|
||
ASSERT((Resource->Flag & ResourceNeverExclusive) == 0);
|
||
|
||
/* Get the thread */
|
||
Thread = ExGetCurrentResourceThread();
|
||
|
||
/* Sanity check and validation */
|
||
ASSERT(KeIsExecutingDpc() == FALSE);
|
||
ExpVerifyResource(Resource);
|
||
|
||
/* Acquire the lock */
|
||
ExAcquireResourceLock(Resource, &LockHandle);
|
||
|
||
/* Check if there is an owner */
|
||
if (!Resource->ActiveCount)
|
||
{
|
||
/* No owner, give exclusive access */
|
||
Resource->Flag |= ResourceOwnedExclusive;
|
||
Resource->OwnerEntry.OwnerThread = Thread;
|
||
Resource->OwnerEntry.OwnerCount = 1;
|
||
Resource->ActiveCount = 1;
|
||
Resource->ActiveEntries = 1;
|
||
Acquired = TRUE;
|
||
}
|
||
else if ((IsOwnedExclusive(Resource)) &&
|
||
(Resource->OwnerEntry.OwnerThread == Thread))
|
||
{
|
||
/* Do a recursive acquire */
|
||
Resource->OwnerEntry.OwnerCount++;
|
||
Acquired = TRUE;
|
||
}
|
||
|
||
/* Release the resource */
|
||
ExReleaseResourceLock(Resource, &LockHandle);
|
||
return Acquired;
|
||
}
|
||
|
||
/*++
|
||
* @name ExEnterCriticalRegionAndAcquireResourceExclusive
|
||
* @implemented NT5.1
|
||
*
|
||
* The ExEnterCriticalRegionAndAcquireResourceExclusive enters a critical
|
||
* region and then exclusively acquires a resource.
|
||
*
|
||
* @param Resource
|
||
* Pointer to the resource to acquire.
|
||
*
|
||
* @return Pointer to the Win32K thread pointer of the current thread.
|
||
*
|
||
* @remarks See ExAcquireResourceExclusiveLite.
|
||
*
|
||
*--*/
|
||
PVOID
|
||
NTAPI
|
||
ExEnterCriticalRegionAndAcquireResourceExclusive(IN PERESOURCE Resource)
|
||
{
|
||
/* Enter critical region */
|
||
KeEnterCriticalRegion();
|
||
|
||
/* Acquire the resource */
|
||
NT_VERIFY(ExAcquireResourceExclusiveLite(Resource, TRUE));
|
||
|
||
/* Return the Win32 Thread */
|
||
return KeGetCurrentThread()->Win32Thread;
|
||
}
|
||
|
||
/*++
|
||
* @name ExEnterCriticalRegionAndAcquireResourceShared
|
||
* @implemented NT5.2
|
||
*
|
||
* The ExEnterCriticalRegionAndAcquireResourceShared routine
|
||
* enters a critical region and then acquires a resource shared.
|
||
*
|
||
* @param Resource
|
||
* Pointer to the resource to acquire.
|
||
*
|
||
* @return Pointer to the Win32K thread pointer of the current thread.
|
||
*
|
||
* @remarks See ExAcquireResourceSharedLite.
|
||
*
|
||
*--*/
|
||
PVOID
|
||
NTAPI
|
||
ExEnterCriticalRegionAndAcquireResourceShared(IN PERESOURCE Resource)
|
||
{
|
||
/* Enter critical region */
|
||
KeEnterCriticalRegion();
|
||
|
||
/* Acquire the resource */
|
||
NT_VERIFY(ExAcquireResourceSharedLite(Resource, TRUE));
|
||
|
||
/* Return the Win32 Thread */
|
||
return KeGetCurrentThread()->Win32Thread;
|
||
}
|
||
|
||
/*++
|
||
* @name ExEnterCriticalRegionAndAcquireSharedWaitForExclusive
|
||
* @implemented NT5.2
|
||
*
|
||
* The ExEnterCriticalRegionAndAcquireSharedWaitForExclusive routine
|
||
* enters a critical region and then acquires a resource shared if
|
||
* shared access can be granted and there are no exclusive waiters.
|
||
* It then acquires the resource exclusively.
|
||
*
|
||
* @param Resource
|
||
* Pointer to the resource to acquire.
|
||
*
|
||
* @return Pointer to the Win32K thread pointer of the current thread.
|
||
*
|
||
* @remarks See ExAcquireSharedWaitForExclusive.
|
||
*
|
||
*--*/
|
||
PVOID
|
||
NTAPI
|
||
ExEnterCriticalRegionAndAcquireSharedWaitForExclusive(IN PERESOURCE Resource)
|
||
{
|
||
/* Enter critical region */
|
||
KeEnterCriticalRegion();
|
||
|
||
/* Acquire the resource */
|
||
NT_VERIFY(ExAcquireSharedWaitForExclusive(Resource, TRUE));
|
||
|
||
/* Return the Win32 Thread */
|
||
return KeGetCurrentThread()->Win32Thread;
|
||
}
|
||
|
||
/*++
|
||
* @name ExReleaseResourceAndLeaveCriticalRegion
|
||
* @implemented NT5.1
|
||
*
|
||
* The ExReleaseResourceAndLeaveCriticalRegion release a resource and
|
||
* then leaves a critical region.
|
||
*
|
||
* @param Resource
|
||
* Pointer to the resource to release.
|
||
*
|
||
* @return None
|
||
*
|
||
* @remarks See ExReleaseResourceLite.
|
||
*
|
||
*--*/
|
||
VOID
|
||
FASTCALL
|
||
ExReleaseResourceAndLeaveCriticalRegion(IN PERESOURCE Resource)
|
||
{
|
||
/* Release the resource */
|
||
ExReleaseResourceLite(Resource);
|
||
|
||
/* Leave critical region */
|
||
KeLeaveCriticalRegion();
|
||
}
|