VSI OpenVMS Wiki - User contributions [en]

PSWAPM

2025-09-11T13:57:51Z

Ambiguous column name: Created page with "'''PSWAPM''' is a privilege that allows a process to control whether it can be swapped out of the balance set by executing the Set Process Swap Mode ($SETSWM) system service. A process must have this privilege to lock itself in the balance set (to disable swapping) or to unlock itself from the balance set (to enable swapping). With this privilege, a process can create a process that is locked in the balance set (swap mode is disab..."

'''PSWAPM''' is a [[Privileges|privilege]] that allows a process to control whether it can be [[Swapping|swapped]] out of the balance set by executing the [[$SETSWM|Set Process Swap Mode ($SETSWM)]] system service. A process must have this privilege to lock itself in the balance set (to disable swapping) or to unlock itself from the balance set (to enable swapping).

With this privilege, a process can create a process that is locked in the balance set (swap mode is disabled) by using an optional argument to the [[$CREPRC|Create Process ($CREPRC)]] system service or, when the DCL command [[RUN]] is used to create a process, by using the /NOSWAPPING qualifier of the RUN command. Furthermore, a process can lock a page or range of pages in physical memory using the [[$LCKPAG|Lock Pages in Memory ($LCKPAG)]] system service.

This privilege should only be granted to users who need to lock a process in memory for performance reasons. Typically, this will be a real-time process. If unqualified processes have the unrestricted ability to lock processes in the balance set, physical memory can be held unnecessarily and thereby degrade system performance.

[[Category:System Privileges]]

SYSTEM privileges

2025-09-11T13:57:38Z

Ambiguous column name:

'''SYSTEM''' is a group of [[Privileges|privileges]] that have the potential to interfere with normal system operation. It includes:

* [[ALTPRI]] allows a process to increase its own priority, set the base priority of a target process, and change the priority of its batch and print jobs
* [[AUDIT (privilege)|AUDIT]] allows software to append audit records to the system [[Security Audit|security audit log file]]
* [[OPER]] allows a process to use the [[OPCOM]] process to reply to users' requests, broadcast messages to all terminals, designate terminals as operator's terminals, etc
* [[PSWAPM]] allows a process to control whether it can be [[Swapping|swapped]] out of the balance set
* [[SECURITY]] allows a process to perform security-related functions such as modifying the [[System Password|system password]] or [[Security Audit|security audit settings]]
* [[SYSLCK]] allows a process to lock systemwide resources or obtain information about a systemwide resource
* [[WORLD]] allows a process to affect other processes on the system: suspend, resume, wake, delete them, control their priority, etc

[[Category:System Privileges]]

$FORCEX

2024-12-11T09:31:37Z

Ambiguous column name: Remove typo

'''SYS$FORCEX''', or '''Force Exit''', is a [[System Service|system service]] that causes an Exit ($EXIT) service call to be issued on behalf of a specified process.

=Description=
The Force Exit service causes an Exit service call to be issued on behalf of a specified process.

If you specify neither the [[#pidadr|pidadr]] nor the [[#prcnam|prcnam]] argument, the caller is forced to exit and control is not returned.

If the longword at address [[#pidadr|pidadr]] is 0, the PID of the target process is returned.

The Force Exit system service requires system dynamic memory.

The image executing in the target process follows normal exit procedures. For example, if any exit handlers have been specified, they gain control before the actual exit occurs. Use the [[$DELPRC|Delete Process ($DELPRC) service]] if you do not want a normal exit.

When a forced exit is requested for a process, a user-mode asynchronous system trap (AST) is queued for the target process. The AST routine causes the $EXIT service call to be issued by the target process. Because the AST mechanism is used, user mode ASTs must be enabled for the target process, or no exit occurs until ASTs are reenabled. Thus, for example, a suspended process cannot be stopped by $FORCEX. The process that calls $FORCEX receives no notification that the exit is not being performed.

If an exit handler resumes normal processing, the process will not exit. In particular, if the program is written in Ada and there is a task within the program that will not terminate, the program will not exit.

The $FORCEX service completes successfully if a force exit request is already in effect for the target process but the exit is not yet completed.

=Syntax=

<nowiki>SYS$FORCEX [</nowiki>[[#pidadr|pidadr]]<nowiki>] ,[</nowiki>[[#prcnam|prcnam]]<nowiki>] ,[</nowiki>[[#code|code]]<nowiki>]</nowiki>

'''C Prototype'''

<nowiki>int sys$forcex (unsigned int *pidadr, void *prcnam, unsigned int code);</nowiki>

=Arguments=
==pidadr==
{{SyservArgument|process_id|longword (unsigned)|modify|by reference}}

[[PID|Process identification (PID)]] of the process to be forced to exit. The pidadr argument is the address of a longword containing the PID. The pidadr argument can refer to a process running on the local node or a process running on another node in the [[Cluster|OpenVMS Cluster system]].

The pidadr argument is optional but must be specified if the process that is to be forced to exit is not in the same [[UIC]] group as the calling process.

==prcnam==
{{SyservArgument|process_name|character-coded text string|read only|by descriptor–fixed-length string descriptor}}

Process name of the [[Process|process]] that is to be forced to exit. The prcnam argument is the address of a character string descriptor pointing to the process name string. A process running on the local node can be identified with a 1- to 15-character string. To identify a process on a particular node in a [[Cluster|cluster]], specify the full process name, which includes the node name as well as the process name. The full process name can contain up to 23 characters.

The prcnam argument can be used only on behalf of processes in the same [[UIC]] group as the calling process. To force processes in other groups to exit, you must specify the [[#pidadr|pidadr]] argument. This restriction exists because the operating system interprets the UIC group number of the calling process as part of the specified process name; the names of processes are unique to UIC groups.

==code==
{{SyservArgument|cond_value|longword (unsigned)|read only|by value}}

Completion code value to be used as the exit parameter. The code argument is a longword containing this value. If you do not specify the code argument, the value 0 is passed as the completion code.

=Condition Values Returned=
{| class="wikitable"
! colspan="col" | Value
! colspan="col" | Description
|-
| SS$_NORMAL
| The service completed successfully.
|-
| SS$_ACCVIO
| The item list cannot be read by the caller, or the buffer length or buffer cannot be written by the caller.
|-
| SS$_INCOMPAT
| The remote node is running an incompatible version of the operating system.
|-
| SS$_INSFMEM
| The system dynamic memory is insufficient for the operation.
|-
| SS$_IVLOGNAM
| The process name string has a length equal to 0 or greater than 15.
|-
| SS$_NONEXPR
| The specified process does not exist, or an invalid process identification was specified.
|-
| SS$_NOPRIV
| The process does not have the privilege to obtain information about the specified process.
|-
| SS$_NOSUCHNODE
| The specified node is not currently a member of the cluster.
|-
| SS$_REMRSRC
| The remote node has insufficient resources to respond to the request. (Bring this error to theattention of your system manager.)
|-
| SS$_UNREACHABLE
| The remote node is a member of the cluster but is not accepting requests. This is normal for a brief period early in the system boot process.
|}

=Privileges Required=
Depending on the operation, the calling process might need a certain privilege to use $FORCEX:
* You need GROUP privilege to force an exit for a process in the same group that does not have the same UIC as the calling process.
* You need WORLD privilege to force an exit for any process in the system.

=Quota Required=
None

=See also=
* [[$CANEXH]]
* [[$CREPRC]]
* [[$DCLEXH]]
* [[$DELPRC]]
* [[$EXIT]]
* [[$GETJPI]]
* [[$GETJPIW]]
* [[$HIBER]]
* [[$PROCESS_SCAN]]
* [[$RESUME]]
* [[$SETPRI]]
* [[$SETPRN]]
* [[$SETPRV]]
* [[$SETRWM]]
* [[$SUSPND]]
* [[$WAKE]]

[[Category:System Services]]