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midl_user_allocate attribute

The midl_user_allocate function is a function that client and server applications provide to allocate memory.


void __RPC_FAR * __RPC_API midl_user_allocate (size_t cBytes);

Parameters

cBytes

Specifies the count of bytes to allocate.

Remarks

Both client applications and server applications must implement the midl_user_allocate function, unless you are compiling in OSF-compatibility (/osf) mode. Applications and generated stubs call midl_user_allocate when dealing with objects referenced by pointers:

  • The server application should call midl_user_allocate to allocate memory for the application—for example, when creating a new node.
  • The server stub calls midl_user_allocate when unmarshaling pointed-at data into the server address space.
  • The client stub calls midl_user_allocate when unmarshaling data from the server that is referenced by an out pointer. Note that for [in], [out], and [unique] pointers, the client stub calls midl_user_allocate only if the [unique] pointer value was NULL on input and changes to a non-NULL value during the call. If the [unique] pointer was non-NULL on input, the client stub writes the associated data into existing memory.

If midl_user_allocate fails to allocate memory, it must return a NULL pointer.

It is recommended that midl_user_allocate return a pointer that is 8 bytes aligned.

Examples


#include <windows.h>

void __RPC_FAR * __RPC_API midl_user_allocate(size_t cBytes) 
{ 
    return(malloc(cBytes)); 
}


See also

allocate
arrays
Arrays and Pointers
Array and Sized-Pointer Attributes
in
midl_user_free
/osf
out
ptr
ref
unique

 

 

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