Context services exit routines

Your resource manager can provide exit routines to be invoked when events occur for its interest in a context. Table 1 lists the context services exit routines.

Table 1. Context Services Exit Routines
Exit Routine	Exit Number in: Hexadecimal (Decimal) Equate Symbol	Event
CONTEXT_SWITCH	2 (2) CTX_SWITCH_EXIT	A call to the Switch_Context service or the termination of a disassociated context
END_CONTEXT	4 (4) CTX_END_CONTEXT_EXIT	A context is ending for any reason, including a call to the End_Context service
EOM_CONTEXT	5 (5) CTX_EOM_CONTEXT_EXIT	A context is ending because the address space associated with it is ending. This exit routine is invoked before the END_CONTEXT exit routine
EXIT_FAILED	1 (1) CTX_EXIT_FAILED_EXIT	A context services exit routine failed
PVT_CONTEXT_OWNER	3 (3) CTX_PRIVATE_CONTEXT_ OWNER	A work unit associated with a private context is ending

These exit routines are optional. A resource manager could, for example, use context services without any exit routine and call the Express_Context_Interest service just to keep data in the context_interest_data area the service provides. If, however, your resource manager does choose to provide any context services exit routines, it must also provide an EXIT_FAILED exit routine.

When a context ends, the exit routines that context services invokes, and the order in which context services invokes the routines, depend on:

The type of context (privately-managed context or native context)
The reason the context is ending

Figure 1 shows the conditions and the order in which exit routines are invoked.

Figure 1. Order of Invocation for Context Services Exit Routines

For a privately-managed context:

When the task associated with the context ends:
1. PVT_CONTEXT_OWNER
2. CONTEXT_SWITCH (if the owner tells RRS to disassociate the context from the task)
3. END_CONTEXT
When the address space associated with the context ends:
1. PVT_CONTEXT_OWNER
2. CONTEXT_SWITCH (if the owner tells RRS to disassociate the context from the task — see note 1)
3. EOM_CONTEXT
4. END_CONTEXT (see note 2)
When the context is not associated with a task and its owner ends:
1. EOM_CONTEXT
2. CONTEXT_SWITCH
3. END_CONTEXT (see note 2)
When the End_Context service was called to end a context associated with a task:
1. END_CONTEXT
When the End_Context service was called to end a context not associated with a task:
1. CONTEXT_SWITCH
2. END_CONTEXT

For a native context:

When the task associated with the context ends:
1. END_CONTEXT
When the address space associated with the context ends:
1. EOM_CONTEXT
2. END_CONTEXT (see note 2)
When the End_Context service was called to end the context:
1. END_CONTEXT

Note:

If the PVT_CONTEXT_OWNER exit routine tells context services to disassociate the context from the task, context services drives CONTEXT_SWITCH exit routines. If any CONTEXT_SWITCH exit routine disallows the switch, context services continues processing to end the context, but it changes the reason for the context end to CTX_FORCED_END_OF_CONTEXT.
During processing the end of an address space, context services invokes the CONTEXT_SWITCH, EOM_CONTEXT, and PVT_CONTEXT_OWNER exit routines before the RTM resource managers (RESMGRs).