NdisAcquireSpinLock
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(
IN PNDIS_SPIN_LOCK SpinLock );
Parameters
- SpinLock
Pointer to an opaque spin lock, already initialized by the caller.
Remarks
In Windows CE, 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 lock(s) 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 spin lock acquired with the NdisDprAcquireSpinLock function must be released with the NdisDprReleaseSpinLock function.
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 the 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 runs at IRQL <=DISPATCH_LEVEL.
Requirements
| Runs on | Versions | Defined in | Include | Link to |
|---|---|---|---|---|
| Windows CE OS | 2.0 and later | Ndis.h |
Note This API is part of the complete Windows CE OS package as provided by Microsoft. The functionality of a particular platform is determined by the original equipment manufacturer (OEM) and some devices may not support this API.
See Also
NdisDprAcquireSpinLock, NdisMSynchronizeWithInterrupt, NdisReleaseSpinLock
Last updated on Tuesday, July 13, 2004
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