remlock.c File Reference

#include <nt.h>
#include <ntrtl.h>
#include <ntos.h>
#include <remlock.h>

Go to the source code of this file.

Defines
#define	MinutesToTicks(x)
Functions
NTSYSAPI PRTL_REMOVE_LOCK NTAPI	RtlAllocateRemoveLock (IN ULONG MaxLockedMinutes, IN ULONG AllocateTag, IN ULONG HighWatermark)
NTSYSAPI NTSTATUS NTAPI	RtlAcquireRemoveLockEx (IN PRTL_REMOVE_LOCK RemoveLock, IN OPTIONAL PVOID Tag, IN PCSTR File, IN ULONG Line)
NTSYSAPI VOID NTAPI	RtlReleaseRemoveLock (IN PRTL_REMOVE_LOCK RemoveLock, IN PVOID Tag)
NTSYSAPI VOID NTAPI	RtlReleaseRemoveLockAndWait (IN PRTL_REMOVE_LOCK RemoveLock, IN PVOID Tag)

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Define Documentation

#define MinutesToTicks (  x   )

Value: (ULONGLONG) KeQueryTimeIncrement() * \ 10 * \ 1000 * \ 1000 * \ 60 * \ x Definition at line 36 of file rtl/remlock.c.

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Function Documentation

NTSYSAPI NTSTATUS NTAPI RtlAcquireRemoveLockEx (  IN PRTL_REMOVE_LOCK  RemoveLock, IN OPTIONAL PVOID  Tag, IN PCSTR  File, IN ULONG  Line )

Definition at line 91 of file rtl/remlock.c. References ASSERTMSG, ExAllocatePoolWithTag, FALSE, File, KeAcquireSpinLock, KeQueryTickCount(), KeReleaseSpinLock(), KeSetEvent(), NonPagedPool, NTSTATUS(), and NULL. : This routine is called to acquire the remove lock for a device object. While the lock is held, the caller can assume that no pending pnp REMOVE requests will be completed. The lock should be acquired immediately upon entering a dispatch routine. It should also be acquired before creating any new reference to the device object if there's a chance of releasing the reference before the new one is done. Arguments: RemoveLock - A pointer to an initialized REMOVE_LOCK structure. Tag - Used for tracking lock allocation and release. If an irp is specified when acquiring the lock then the same Tag must be used to release the lock before the Tag is completed. File - set to __FILE__ as the location in the code where the lock was taken. Line - set to __LINE__. Return Value: Returns whether or not the remove lock was obtained. If successful the caller should continue with work calling RtlReleaseRemoveLock when finished. If not successful the lock was not obtained. The caller should abort the work but not call RtlReleaseRemoveLock. --*/ { LONG lockValue; NTSTATUS status; #if DBG PRTL_REMOVE_LOCK_TRACKING_BLOCK trackingBlock; #endif // // Grab the remove lock // lockValue = InterlockedIncrement(&RemoveLock->IoCount); ASSERTMSG("RtlAcquireRemoveLock - lock value was negative : ", (lockValue > 0)); ASSERTMSG("RemoveLock increased to meet LockHighWatermark", ((0 == RemoveLock->HighWatermark) || (lockValue <= RemoveLock->HighWatermark))); if (! RemoveLock->Removed) { #if DBG trackingBlock = ExAllocatePoolWithTag( NonPagedPool, sizeof(RTL_REMOVE_LOCK_TRACKING_BLOCK), RemoveLock->AllocateTag); RtlZeroMemory (trackingBlock, sizeof (RTL_REMOVE_LOCK_TRACKING_BLOCK)); if (NULL == trackingBlock) { ASSERTMSG ("insufficient resources", FALSE); } else { KIRQL oldIrql; trackingBlock->Tag = Tag; trackingBlock->File = File; trackingBlock->Line = Line; KeQueryTickCount(&trackingBlock->TimeLocked); KeAcquireSpinLock (&RemoveLock->Spin, &oldIrql); trackingBlock->Link = RemoveLock->Blocks.Link; RemoveLock->Blocks.Link = trackingBlock; KeReleaseSpinLock(&RemoveLock->Spin, oldIrql); } #endif status = STATUS_SUCCESS; } else { if (0 == InterlockedDecrement (&RemoveLock->IoCount)) { KeSetEvent (&RemoveLock->RemoveEvent, 0, FALSE); } status = STATUS_DELETE_PENDING; } return status; }

NTSYSAPI PRTL_REMOVE_LOCK NTAPI RtlAllocateRemoveLock (  IN ULONG  MaxLockedMinutes, IN ULONG  AllocateTag, IN ULONG  HighWatermark )

Definition at line 50 of file rtl/remlock.c. References ExAllocatePoolWithTag, FALSE, _RTL_REMOVE_LOCK::IoCount, KeInitializeEvent, KeInitializeSpinLock(), NonPagedPool, NULL, _RTL_REMOVE_LOCK::Removed, _RTL_REMOVE_LOCK::RemoveEvent, RTL_REMOVE_LOCK, RTL_REMOVE_LOCK_SIG, and _RTL_REMOVE_LOCK::Signature. : This routine is called to initialize the remove lock for a device object. --*/ { PRTL_REMOVE_LOCK lock; lock = ExAllocatePoolWithTag (NonPagedPool, sizeof (RTL_REMOVE_LOCK), AllocateTag); if (lock) { lock->Signature = RTL_REMOVE_LOCK_SIG; lock->Removed = FALSE; lock->IoCount = 1; KeInitializeEvent(&lock->RemoveEvent, SynchronizationEvent, FALSE); #if DBG lock->HighWatermark = HighWatermark; lock->MaxLockedMinutes = MaxLockedMinutes; lock->AllocateTag = AllocateTag; KeInitializeSpinLock (&lock->Spin); lock->Blocks.Link = NULL; #endif } return lock; }

NTSYSAPI VOID NTAPI RtlReleaseRemoveLock (  IN PRTL_REMOVE_LOCK  RemoveLock, IN PVOID  Tag )

Definition at line 204 of file rtl/remlock.c. References ASSERT, ExFreePool(), FALSE, IO_NO_INCREMENT, KeAcquireSpinLock, KeQueryTickCount(), KeReleaseSpinLock(), KeSetEvent(), MinutesToTicks, NULL, and TRUE. : This routine is called to release the remove lock on the device object. It must be called when finished using a previously locked reference to the device object. If an Tag was specified when acquiring the lock then the same Tag must be specified when releasing the lock. When the lock count reduces to zero, this routine will signal the waiting event to release the waiting thread deleting the device object protected by this lock. Arguments: DeviceObject - the device object to lock Tag - The tag (if any) specified when acquiring the lock. This is used for lock tracking purposes Return Value: none --*/ { LONG lockValue; #if DBG KIRQL oldIrql; LARGE_INTEGER difference; BOOLEAN found; LONGLONG maxTime; PRTL_REMOVE_LOCK_TRACKING_BLOCK last; PRTL_REMOVE_LOCK_TRACKING_BLOCK current; // // Check the tick count and make sure this thing hasn't been locked // for more than MaxLockedMinutes. // found = FALSE; KeAcquireSpinLock(&RemoveLock->Spin, &oldIrql); last = (&RemoveLock->Blocks); current = last->Link; // // Note the first one is the sentinal // while (NULL != current) { KeQueryTickCount((&difference)); difference.QuadPart -= current->TimeLocked.QuadPart; maxTime = MinutesToTicks (RemoveLock->MaxLockedMinutes); if (maxTime && (maxTime < difference.QuadPart)) { KdPrint(("RtlReleaseRemoveLock: Lock %#08lx (tag %#08lx) locked " "for %I64d ticks - TOO LONG\n", RemoveLock, current->Tag, difference.QuadPart)); KdPrint(("RtlReleaseRemoveLock: Lock acquired in file " "%s on line %d\n", current->File, current->Line)); ASSERT(FALSE); } if ((!found) && (current->Tag == Tag)) { found = TRUE; last->Link = current->Link; ExFreePool (current); current = last->Link; continue; } last = current; current = current->Link; } KeReleaseSpinLock(&RemoveLock->Spin, oldIrql); if (!found) { KdPrint (("RtlReleaseRemoveLock: Couldn't find Tag %#08lx " "in the lock tracking list\n", Tag)); ASSERT(FALSE); } #endif lockValue = InterlockedDecrement(&RemoveLock->IoCount); ASSERT(0 <= lockValue); if (0 == lockValue) { ASSERT (RemoveLock->Removed); // // The device needs to be removed. Signal the remove event // that it's safe to go ahead. // KeSetEvent(&RemoveLock->RemoveEvent, IO_NO_INCREMENT, FALSE); } return; }

NTSYSAPI VOID NTAPI RtlReleaseRemoveLockAndWait (  IN PRTL_REMOVE_LOCK  RemoveLock, IN PVOID  Tag )

Definition at line 328 of file rtl/remlock.c. References ASSERT, Executive, ExFreePool(), FALSE, KernelMode, KeWaitForSingleObject(), NULL, PAGED_CODE, and TRUE. : This routine is called when the client would like to delete the remove- locked resource. This routine will block until all the remove locks have completed. This routine MUST be called after acquiring once more the lock. Arguments: RemoveLock - Return Value: none --*/ { LONG ioCount; PAGED_CODE (); RemoveLock->Removed = TRUE; ioCount = InterlockedDecrement (&RemoveLock->IoCount); ASSERT (0 < ioCount); if (0 < InterlockedDecrement (&RemoveLock->IoCount)) { KeWaitForSingleObject (&RemoveLock->RemoveEvent, Executive, KernelMode, FALSE, NULL); } #if DBG ASSERT (RemoveLock->Blocks.Link); if (Tag != RemoveLock->Blocks.Link->Tag) { KdPrint (("RtlRelaseRemoveLockAndWait last tag invalid %x %x\n", Tag, RemoveLock->Blocks.Link->Tag)); ASSERT (Tag != RemoveLock->Blocks.Link->Tag); } ExFreePool (RemoveLock->Blocks.Link); #endif }

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