NdisDprFreePacketNonInterlocked

NdisDprFreePacketNonInterlocked releases a driver-allocated packet descriptor and returns it to the free list when the caller provides internal synchronization for accessing packet pool. Because Windows CE does not support DPC IRQL, all NdisDprXXX functions perform identically to the non-DPR equivalent.

VOID NdisDprFreePacketNonInterlocked(
  PNDIS_PACKET Packet
);

Parameters

• Packet
  [in] Pointer to a packet descriptor returned by NdisDprAllocatePacketNonInterlocked.

Return Values

None.

Remarks

Before calling NdisDprFreePacketNonInterlocked, the driver either must call NdisFreeBuffer as many times as necessary to release all buffer descriptors chained to the packet, or it must call an NdisUnchainBufferAtXxx function as many times as necessary to save all pointers to buffer descriptors. Otherwise, memory associated with buffer descriptors in the chain remains unusable by the driver

A driver that calls NdisDprFreePacketNonInterlocked (and its reciprocal NdisDprAllocatePacketNonInterlocked) is responsible for synchronizing all accesses to the packet pool that driver allocated with NdisAllocatePacketPool. Usually, such a driver protects its packet pool with a driver-allocated spin lock. First, the driver calls NdisAcquireSpinLock. When the driver resumes execution with a locked packet pool, it calls NdisDprFreePacketNonInterlocked. Finally, the driver releases its spin lock with NdisReleaseSpinLock when NdisDprFreePacketNonInterlocked returns control.

A driver that does not manage this synchronization should let NDIS manage this synchronization on its behalf by calling NdisAllocate/FreePacket or NdisDprAllocate/FreePacket.

Requirements

OS Versions: Windows CE .NET 4.0 and later.
Header: Ndis.h.

See Also

MiniportDisableInterrupt | MiniportISR | MiniportSynchronizeISR | NdisAcquireSpinLock | NdisAllocatePacket | NdisAllocatePacketPool | NdisAllocateSpinLock | NdisDprAllocatePacket | NdisDprFreePacket | NdisDprAllocatePacketNonInterlocked | NdisDprReleaseSpinLock | NdisFreeBuffer | NdisFreePacket | NdisMSynchronizeWithInterrupt | NdisReleaseSpinLock

 Last updated on Tuesday, May 18, 2004

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