Binder Language Example 2

As progress is made in developing the application, a program called BANKER is written. BANKER needs to use the procedure called Payment in the service program called FINANCIAL. The resulting application with the BANKER program is shown in Figure 1.

Figure 1. Using the Service Program FINANCIAL

When the BANKER program was created, the MYLIB/FINANCIAL service program was provided on the BNDSRVPGM parameter. The symbol Payment was found to be exported from the fourth slot of the public interface of the FINANCIAL service program. The current signature of MYLIB/FINANCIAL along with the slot associated with the Payment interface is saved with the BANKER program.

During the process of getting BANKER ready to run, activation verifies the following:

• Service program FINANCIAL in library MYLIB can be found.
• The service program still supports the signature (SIG 123) saved in BANKER.

This signature checking verifies that the public interface used by BANKER when it was created is still valid at runtime.

As shown in Figure 1, at the time BANKER gets called, MYLIB/FINANCIAL still supports the public interface used by BANKER. If activation cannot find either a matching signature in MYLIB/FINANCIAL or the service program MYLIB/FINANCIAL, the following occurs:

• BANKER fails to get activated.
• An error message is issued.