NdisAcquireSpinLock macro (ndis.h)

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.

Syntax

void NdisAcquireSpinLock(
  [in]  _SpinLock
);

Parameters

[in] _SpinLock

Pointer to an opaque spin lock, already initialized by the caller.

Return value

None

Remarks

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 spin lock acquired with NdisAcquireSpinLock must be released with NdisReleaseSpinLock. A spin lock acquired with NdisDprAcquireSpinLock must be released with NdisDprReleaseSpinLock.

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.

Requirements

See also

MiniportDisableInterruptEx

MiniportHaltEx

MiniportInitializeEx

MiniportInterrupt

NdisAllocateSpinLock

NdisDprAcquireSpinLock

NdisReleaseSpinLock