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NdisDprAcquireSpinLock (NDIS 5.1) function

Note   NDIS 5. x has been deprecated and is superseded by NDIS 6. x. For new NDIS driver development, see Network Drivers Starting with Windows Vista. For information about porting NDIS 5. x drivers to NDIS 6. x, see Porting NDIS 5.x Drivers to NDIS 6.0.

NdisDprAcquireSpinLock acquires a spin lock so the caller can synchronize access to resources shared among non-ISR driver functions in a multiprocessor-safe way.

Syntax


VOID NdisDprAcquireSpinLock(
  _In_ PNDIS_SPIN_LOCK SpinLock
);

Parameters

SpinLock [in]

Pointer to an opaque spin lock, already initialized by the caller.

Return value

None

Remarks

The NIC driver must initialize a variable of type NDIS_SPIN_LOCK with NdisAllocateSpinLock before it calls any other Ndis..SpinLock function. The driver must provide resident storage for the spin lock(s) it uses.

NdisDprAcquireSpinLock is an optimized version of NdisAcquireSpinLock that a miniport driver can call only while running at IRQL = DISPATCH_LEVEL.

After acquiring a spin lock with NdisDprAcquireSpinLock, the caller must release that lock with a call to NdisDprReleaseSpinLock. A NIC driver must call NdisDprReleaseSpinLock following each call to NdisDprAcquireSpinLock. Otherwise, a deadlock occurs, hanging the driver.

A spin lock acquired with NdisDprAcquireSpinLock must be released with NdisDprReleaseSpinLock. A spin lock acquired with NdisAcquireSpinLock must be released with NdisReleaseSpinLock.

A driver should never hold a spin lock for an extended period (more than a few instructions). Holding a spin lock for longer than 25 microseconds degrades both system and driver performance.

A miniport driver cannot use a spin lock to protect resources that its other functions share with the MiniportISR and/or MiniportDisableInterrupt functions. Instead, a miniport driver must call NdisMSynchronizeWithInterrupt so that its MiniportSynchronizeISR function accesses such shared resources at the same DIRQL at which its MiniportISR and/or MiniportDisableInterrupt functions do.

For more information about acquiring and releasing NDIS spin locks, see Synchronization and Notification in Network Drivers.

Requirements

Target platform

Universal

Version

See NdisDprAcquireSpinLock.

Header

Ndis.h (include Ndis.h)

Library

Ndis.lib

IRQL

DISPATCH_LEVEL

See also

MiniportDisableInterrupt
MiniportISR
MiniportSynchronizeISR
MiniportTimer
NdisAcquireSpinLock
NdisAllocateSpinLock
NdisDprReleaseSpinLock
NdisMSynchronizeWithInterrupt

 

 

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