This function acquires a spin lock so that the caller can synchronize access to resources shared among driver functions not related to interrupts in a multiprocessor-safe way.
| Header file: | Ndis.h |
| Windows CE versions: | 2.0 and later |
VOID NdisDprAcquireSpinLock( IN PNDIS_SPIN_LOCK SpinLock );
In Windows CE, NDIS spinlocks are implemented using critical sections.
The NIC driver must initialize a variable of type NDIS_SPIN_LOCK with the NdisAllocateSpinLock function before it calls any other NdisXXXSpinLock function. The driver must provide resident storage for the spin lock( s ) it uses.
This function is an optimized version of NdisAcquireSpinLock that a miniport can call only while running at IRQL DISPATCH_LEVEL.
After acquiring a spin lock with this function, the caller must release that lock with a call to the NdisDprReleaseSpinLock function. An NIC driver must call NdisDprReleaseSpinLock following each call to this function. Otherwise, a deadlock occurs, hanging the driver.
A spin lock acquired with this function 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 the NdisMSynchronizeWithInterrupt function so that its MiniportSynchronizeISR function accesses such shared resources at the same DIRQL at which its MiniportISR and/or MiniportDisableInterrupt functions do.
A driver that calls this function must be running at IRQL DISPATCH_LEVEL.
NdisAcquireSpinLock, NdisDprReleaseSpinLock, NdisMSynchronizeWithInterrupt