RpcSmAllocate function (rpcndr.h)

Article
04/02/2021

The RpcSmAllocate function allocates memory within the RPC stub memory management function and returns a pointer to the allocated memory or NULL.

Syntax

void * RpcSmAllocate(
  size_t     Size,
  RPC_STATUS *pStatus
);

Parameters

Size

Size of memory to allocate, in bytes.

pStatus

Pointer to the returned status.

Return value

Value	Meaning
RPC_S_OK	The call succeeded.
RPC_S_OUT_OF_MEMORY	The system is out of memory.

Note For a list of valid error codes, see RPC Return Values.

Remarks

The RpcSmAllocate routine allows an application to allocate memory within the RPC stub memory–management environment. Prior to calling RpcSmAllocate, the memory-management environment must already be established. For memory management called within the stub, the server stub itself may establish the necessary environment. For more information, see RpcSmEnableAllocate. When using RpcSmAllocate to allocate memory not called from the stub, the application must call RpcSmEnableAllocate to establish the required memory-management environment.

The RpcSmAllocate routine returns a pointer to the allocated memory if the call is successful. Otherwise, a NULL is returned.

When the stub establishes the memory management, it frees any memory allocated by RpcSmAllocate. The application can free such memory before returning to the calling stub by calling RpcSmFree.

By contrast, when the application establishes the memory management, it must free any memory allocated. It does so by calling either RpcSmFree or RpcSmDisableAllocate.

To manage the same memory within the stub memory–management environment, multiple threads can call RpcSmAllocate and RpcSmFree. In this case, the threads must share the same stub memory management thread handle. Applications pass thread handles from thread to thread by calling RpcSmGetThreadHandle and RpcSmSetThreadHandle.

For more information, see Memory Management.

Requirements

Requirement	Value
Minimum supported client	Windows 2000 Professional [desktop apps \| UWP apps]
Minimum supported server	Windows 2000 Server [desktop apps \| UWP apps]
Target Platform	Windows
Header	rpcndr.h (include Rpc.h)
Library	Rpcrt4.lib
DLL	Rpcrt4.dll