osi_selpost — Post a process waiting for select

Function

The osi_selpost service posts a process that is waiting because of a select request.

Requirements

Operation	Environment
Authorization:	Problem or supervisor state, any PSW key
Dispatchable unit mode:	Task or SRB
Cross memory mode:	Any
AMODE:	31-bit
ASC mode:	Any
Interrupt status:	Enabled for interrupts
Locks:	Unlocked
Control parameters:	All parameters must be addressable by the caller and in the primary address space.

Format

     osi_selpost(Select_token,
              Return_value,
              Return_code,
              Reason_code);

Parameters

Select_token

Supplied parameter

Type:: Token
Length:: 16 bytes

Select_token is the token that was saved by the PFS when it was called for the select query request. The PFS does not need to be aware of the contents of this field; it just needs to save it on the select request and pass it to this module when it is time to post.

Return_value

Returned parameter

Type:: Integer
Length:: Fullword

A fullword in which the osi_selpost operation returns the results of the operation, as one of the following:

Return_value: Meaning
-1: The operation was not successful.
0: The operation was successful.

Return_code

Returned parameter

Type:: Integer
Length:: Fullword

A fullword in which the osi_selpost operation stores the return code. The osi_selpost operation returns Return_code only if Return_value is -1. For a complete list of supported return code values, see z/OS UNIX System Services Messages and Codes.

Reason_code

Returned parameter

Type:: Integer
Length:: Fullword

A fullword in which the osi_selpost operation stores the reason code. The osi_selpost operation returns Reason_code only if Return_value is -1. Reason_code further qualifies the Return_code value.

Usage notes

For additional information, see Select/poll processing.
The task that is posted is the task that is represented by Select_token. Before a PFS uses osi_selpost, it should copy the Select_token to a place that is addressable by the task that will perform the osi_selpost.
The PFS must never call osi_selpost for a waiting process more than once, and it should have sufficient logic and recovery to avoid calling osi_selpost for a task that is no longer waiting.
The address of the osi_selpost routine is passed to the PFS in the OSIT structure when the PFS is initialized.

Related services

vn_select — Select or poll on a vnode

Characteristics and restrictions

The caller of this service must be on a process thread.