NdisDprAcquireSpinLock (Windows Embedded CE 6.0)
1/6/2010
NdisDprAcquireSpinLock acquires a spin lock so the caller can synchronize access to resources shared among non-ISR driver functions.
However, because Windows Embedded CE does not support DPC IRQL, all NdisDprXXX functions perform identically to the non-DPR equivalent.
Syntax
VOID NdisDprAcquireSpinLock(
PNDIS_SPIN_LOCK SpinLock
);
Parameters
- SpinLock
[in]Pointer to an opaque spin lock, already initialized by the caller.
Return Value
None.
Remarks
The NIC 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 NdisDprAcquireSpinLock, the caller must release that lock with a call to NdisDprReleaseSpinLock. In addition, following each call to NdisDprAcquireSpinLock, a NIC driver must call NdisDprReleaseSpinLock. 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/or MiniportDisableInterrupt functions
Note
A spin lock acquired with NdisDprAcquireSpinLock must be released with NdisDprReleaseSpinLock. A spin lock acquired with NdisAcquireSpinLock must be released with NdisReleaseSpinLock.
Requirements
| Header | ndis.h |
| Library | ndis.lib |
| Windows Embedded CE | Windows CE .NET 4.0 and later |
See Also
Reference
NDIS Library Functions
MiniportDisableInterrupt
MiniportISR
MiniportSynchronizeISR
NdisAcquireSpinLock
NdisAllocateSpinLock
NdisDprReleaseSpinLock
NdisMSynchronizeWithInterrupt
NdisReleaseSpinLock