This function acquires a spin lock so that the caller gains exclusive access to the resources, shared among driver functions, that the spin lock protects.
VOID NdisAcquireSpinLock( PNDIS_SPIN_LOCK SpinLock );
[in] Pointer to an opaque spin lock, already initialized by the caller.
In the Microsoft® Windows® CE .NET operating system (OS), NDIS spin locks are implemented using critical sections.
The driver must initialize a variable of type NDIS_SPIN_LOCK with the NdisAllocateSpinLock function before it calls any other NDIS SpinLock function. The driver must provide resident storage for the spin locks it uses.
After acquiring a spin lock with this function, the caller releases that lock with a call to the NdisReleaseSpinLock function. A driver must call NdisReleaseSpinLock following each call to this function. Otherwise, a deadlock occurs, hanging the driver.
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 the MiniportDisableInterrupt functions. Instead, a miniport must call the NdisMSynchronizeWithInterrupt function so that its MiniportSynchronizeISR function does not access shared resources at the same time as its MiniportISR or MiniportDisableInterrupt function.
OS Versions: Windows CE .NET 4.0 and later.
Last updated on Tuesday, May 18, 2004
© 1992-2003 Microsoft Corporation. All rights reserved.