4.4 I/O Status Block

The I/O status blocks (IOSB) for mailbox read, write, set protection, and get mailbox information QIO functions are shown in Figures Figure 4-8, Figure 4-9, Figure 4-10, and Figure 4-11.

Appendix A lists the I/O status returns for these functions. In addition to the IOSB return values, the following statuses can be returned in R0 by the call to the system service:

SS$_ACCVIO
SS$_EXQUOTA
SS$_ILLIOFUNC
SS$_INSFMEM
SS$_MBFULL
SS$_MBTOOSML
SS$_NOPRIV
SS$_NORMAL

(The OpenVMS system messages documentation provides explanations and suggested user actions for both types of returns.)

Figure 4-8 IOSB Contents — Read Function

Figure 4-9 IOSB Contents— Write Function

Figure 4-10 IOSB Contents— Set Protection Function

Figure 4-11 IOSB Contents — Get Mailbox Information Function