WSPDeregisterRdmaMemory function

Artigo
06/19/2017

WSPDeregisterRdmaMemory releases an RDMA buffer that was registered by a previous call to the WSPRegisterRdmaMemory function.

Syntax

int WSPDeregisterRdmaMemory(
  _In_  SOCKET s,
  _In_  LPVOID lpRdmaBufferDescriptor,
  _In_  DWORD  dwDescriptorLength,
  _Out_ LPINT  lpErrno
);

Parameters

s [in]
Descriptor that identifies a connected socket.
lpRdmaBufferDescriptor [in]
Pointer to a memory block that contains a descriptor. This descriptor identifies the RDMA buffer that was previously registered.
dwDescriptorLength [in]
Size, in bytes, of the memory block at lpRdmaBufferDescriptor.
lpErrno [out]
Pointer to a variable that receives the error code.

Return value

Returns zero if successful; otherwise, returns SOCKET_ERROR and, at lpErrno, the following error code:

Return code	Description
WSAEINVAL	The specified pointer to the descriptor for the RDMA buffer does not represent a previously registered RDMA buffer, or the SAN service provider cannot release the RDMA buffer, because the RDMA buffer is currently being used in an RDMA data transfer operation.

Remarks

The Windows Sockets switch calls the WSPDeregisterRdmaMemory function to release an RDMA buffer that it previously registered in a call to the WSPRegisterRdmaMemory function. In the call to the WSPDeregisterRdmaMemory function, the switch passes the same socket descriptor that it passed to the WSPRegisterRdmaMemory function.

A SAN service provider is not required to return a different RDMA buffer descriptor when the switch makes an additional call to WSPRegisterRdmaMemory to register that RDMA buffer for use by another socket. However, the SAN service provider should maintain an internal reference count of the number of registered instances of that RDMA buffer. Calls to the SAN service provider's WSPDeregisterRdmaMemory entry point decrement this internal reference count. Only the final WSPDeregisterRdmaMemory call, which decrements the internal reference count to zero, releases all resources that the SAN service provider consumed to register the RDMA buffer.

Requirements

Target platform	Desktop
Version	Requires Windows Sockets version 2.2.
Header	Ws2san.h (include Ws2san.h)

Compartilhar via