OSF DCE Application Development Guide--Core Components

OSF DCE Application Development Guide—Core Components

RPC server stubs do not allocate memory. Instead, they rely on the manager code—the

code that the server stubs call—to allocate it for them.

The following sections gives guidelines for how client code and manager code should

use the the various allocation and free routines provided with DCE.

Note: DCE provides two versions of DCE RPC stub support routines. The

rpc_ss_*() routines raise an exception, while the rpc_sm_*() routines

return an error status value. In all other ways, the routines are identical. It

is generally recommended that you use the rpc_sm_*()routines instead of

the rpc_ss_*() routines for compliance with the Application Environment

Speciﬁcation/Distributed Computing.

16.1.1 Usingthe Memory Management Defaults

If it does not matter to the client code which memory allocation routine the RPC client

stubs use, the client code should call the rpc_ss_client_free( ) routine to free any

memory that the client stub allocates and returns. The rpc_ss_client_free( ) routine uses

the current free routine that is in effect. Client code that uses rpc_ss_client_free( ) must

use caution if it calls other routines before it frees all of the pieces of allocated storage

with rpc_ss_client_free(), because it is possible that the called code has been written so

that it swaps in a different allocation/free pair without reestablishing the previous

allocation/free pair on exit.

16.1.2 Usingrpc_ss_allocate and rpc_ss_free

Both client code and manager code can use rpc_ss_allocate() and rpc_ss_free( ). The

next sections describe how.

16.1.2.1 Using rpc_ss_allocate and rpc_ss_free in Manager Code

Manager code uses either the rpc_ss_allocate() and rpc_ss_free( ) routines or the

operating system allocation and free routines to allocate and free memory.

Manager code uses rpc_ss_allocate() to allocate storage for data that the server stub is

to send back to the client. Manager code can either use rpc_ss_free( ) to free the storage

explicitly, or it can rely on the server stub to free it. After the server stub marshalls the

output parameters, it releases any storage that the manager code has allocated with

rpc_ss_allocate().

Manager code can also use the rpc_ss_free() routine to release storage pointed to by a

full pointer in an input parameter and have the freeing of the memory reﬂected on return

to the calling application if the reﬂect_deletions attribute has been speciﬁed as an

operation attribute in the interface deﬁnition. See Chapter 17 for instructions on how to

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