Support for XPLINK

XPLINK support is available for applications running under the following environments:

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:

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 the ims.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.
For more information, see either z/OS V2R1.0 Language Environment Writing Interlanguage Communication Applications or z/OS XL C/C++ Language Reference.

For more information, see XPLINK restrictions.