The NdisAcquireSpinLock function acquires a spin lock so the caller gains exclusive access to the resources, shared among driver functions, that the spin lock protects.
- SpinLock [in]
Pointer to an opaque spin lock, already initialized by the caller.
The 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 NdisAcquireSpinLock, the caller must release that lock with a call to NdisReleaseSpinLock. A driver must call NdisReleaseSpinLock following each call to NdisAcquireSpinLock. 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 MiniportInterrupt and/or MiniportDisableInterruptEx functions. Instead, a miniport driver must call NdisMSynchronizeWithInterruptEx so that its MiniportSynchronizeInterrupt function accesses such shared resources at the same DIRQL at which its MiniportInterrupt and/or MiniportDisableInterruptEx functions do.
For more information about acquiring and releasing NDIS spin locks, see Synchronization and Notification in Network Drivers.
|Supported for NDIS 6.0 and NDIS 5.1 drivers (see NdisAcquireSpinLock (NDIS 5.1)) in Windows Vista. Supported for NDIS 5.1 drivers (see NdisAcquireSpinLock (NDIS 5.1)) in Windows XP.|
DDI compliance rules
|Irql_Synch_Function, SpinLock, SpinLockBalanced, SpinLockDpr, SpinLockDprRelease, SpinlockRelease|