NdisDprAcquireSpinLock

VOID
NdisDprAcquireSpinLock(

IN PNDIS_SPIN_LOCK SpinLock
);

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

Parameters

SpinLock

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

Comments

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 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 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.

Callers of NdisDprAcquireSpinLock must be running at IRQL DISPATCH_LEVEL.

See Also

MiniportDisableInterrupt, MiniportISR, MiniportSynchronizeISR, MiniportTimer, NdisAcquireSpinLock, NdisAllocateSpinLock, NdisDprReleaseSpinLock, NdisMSynchronizeWithInterrupt