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NdisAcquireSpinLock (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 x has been deprecated and is superseded by NDIS 6.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.

NdisAcquireSpinLock acquires a spin lock so the caller gains exclusive access to the resources, shared among driver functions, that the spin lock protects.

Syntax


VOID NdisAcquireSpinLock(
  _In_ PNDIS_SPIN_LOCK SpinLock
);

Parameters

SpinLock [in]

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

Return value

None

Remarks

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

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

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

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 NdisAcquireSpinLock.

Header

Ndis.h (include Ndis.h)

Library

Ndis.lib

IRQL

<= DISPATCH_LEVEL

See also

MiniportDisableInterrupt
MiniportHalt
MiniportInitialize
MiniportISR
MiniportSynchronizeISR
NdisAllocateSpinLock
NdisDprAcquireSpinLock
NdisMSynchronizeWithInterrupt
NdisReleaseSpinLock

 

 

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