Support for XPLINK
XPLINK support is available for
applications running under the following environments:
- Batch
- TSO/E
- z/OS UNIX
It is not available for applications running under CICS® before CICS TS 3.1.
XPLINK support is available with the
compiler for the following programming language:
- z/OS C and C++
There is limited XPLINK support in the
following areas:
- Db2® — EXEC SQL calls are defined using linkage OS which is supported from XPLINK callers.
- IMS — Language Environment provides the CTDLI interface (a
ctdli()
function call) for C and C++ callers. This interface is defined in theims.h
header as using linkage OS which is supported from XPLINK callers. - In general, any system service that is defined as using linkage OS is a supported call from an
XPLINK program.
- If it requires OS linkage conventions but not a Language Environment-conforming stack (that is, it only needs a
72-byte save area), then the function can be defined as OS_NOSTACK (the default when
#pragma linkage(...,OS)
is specified). This option provides the best performance because the compiler generates OS linkage calling conventions directly – no call through glue code is required. - If it requires OS linkage conventions and a Language Environment-conforming stack, then the function can be defined as OS_UPSTACK. For this option, the compiler generates a call through Language Environment glue code that switches to OS linkage conventions and the non-XPLINK upward-growing stack.
- If it requires OS linkage conventions but not a Language Environment-conforming stack (that is, it only needs a
72-byte save area), then the function can be defined as OS_NOSTACK (the default when
For more information, see XPLINK restrictions.