Updated: 11 December 1998

OpenVMS System Services Reference Manual

Allows a process to specify a set of event flags for which it wants to wait.

Format

SYS$WFLAND efn ,mask

C Prototype

int sys$wfland (unsigned int efn, unsigned int mask);

Arguments

efn

OpenVMS usage:	ef_number
type:	longword (unsigned)
access:	read only
mechanism:	by value

Number of any event flag within the event flag cluster to be used. The efn argument is a longword containing this number; however, $WFLAND uses only the low-order byte. Specifying the number of an event flag within the cluster serves to identify the event flag cluster.

There are two local event flag clusters: cluster 0 and cluster 1. Cluster 0 contains event flag numbers 0 to 31, and cluster 1 contains event flag numbers 32 to 63.

There are two common event flag clusters: cluster 2 and cluster 3. Cluster 2 contains event flag numbers 64 to 95, and cluster 3 contains event flag numbers 96 to 127.

mask

OpenVMS usage:	mask_longword
type:	longword (unsigned)
access:	read only
mechanism:	by value

Event flags for which the process is to wait. The mask argument is a longword bit vector wherein a bit, when set, selects the corresponding event flag for which to wait.

Description

The Wait for Logical AND of Event Flags service allows a process to specify a set of event flags for which it wants to wait. The process is put in a wait state until all specified event flags are set, at which time $WFLAND returns to the caller and execution resumes.

The wait state caused by this service can be interrupted by an asynchronous system trap (AST) if (1) the access mode at which the AST executes is equal to or more privileged than the access mode from which the $WAITFR service was issued and (2) the process is enabled for ASTs at that access mode.

When a wait state is interrupted by an AST and after the AST service routine completes execution, the operating system repeats the $WFLAND request on behalf of the process. At this point, if all the specified event flags have been set, the process resumes execution.

Required Access or Privileges

None

Required Quota

None

Related Services

$ASCEFC, $CLREF, $DACEFC, $DLCEFC, $READEF, $SETEF, $WAITFR, $WFLOR

Condition Values Returned

SS$_NORMAL	The service completed successfully.
SS$_ILLEFC	You specified an illegal event flag number.
SS$_UNASEFC	The process is not associated with the cluster containing the specified event flag.

Allows a process to specify a set of event flags for which it wants to wait.

Format

SYS$WFLOR efn ,mask

C Prototype

int sys$wflor (unsigned int efn, unsigned int mask);

Arguments

efn

OpenVMS usage:	ef_number
type:	longword (unsigned)
access:	read only
mechanism:	by value

Number of any event flag within the event flag cluster to be used. The efn argument is a longword containing this number; however, $WFLOR uses only the low-order byte. Specifying the number of an event flag within the cluster serves to identify the event flag cluster.

There are two local event flag clusters: cluster 0 and cluster 1. Cluster 0 contains event flag numbers 0 to 31, and cluster 1 contains event flag numbers 32 to 63.

There are two common event flag clusters: cluster 2 and cluster 3. Cluster 2 contains event flag numbers 64 to 95, and cluster 3 contains event flag numbers 96 to 127.

mask

OpenVMS usage:	mask_longword
type:	longword (unsigned)
access:	read only
mechanism:	by value

Event flags for which the process is to wait. The mask argument is a longword bit vector wherein a bit, when set, selects the corresponding event flag for which to wait.

Description

The Wait for Logical OR of Event Flags service allows a process to specify a set of event flags for which it wants to wait. The process is put in a wait state until any one of the specified event flags is set, at which time $WFLOR returns to the caller and execution resumes.

The wait state caused by this service can be interrupted by an asynchronous system trap (AST) if (1) the access mode at which the AST executes is equal to or more privileged than the access mode from which the $WFLOR service was issued and (2) the process is enabled for ASTs at that access mode.

When a wait state is interrupted by an AST and after the AST service routine completes execution, the operating system repeats the $WFLOR request on behalf of the process. At this point, if any of the specified event flags has been set, the process resumes execution.

Required Access or Privileges

None

Required Quota

None

Related Services

$ASCEFC, $CLREF, $DACEFC, $DLCEFC, $READEF, $SETEF, $WAITFR, $WFLAND

Condition Values Returned

SS$_NORMAL	The service completed successfully.
SS$_ILLEFC	You specified an illegal event flag number.
SS$_UNASEFC	The process is not associated with the cluster containing the specified event flag.

The following table lists the obsolete system services and the current services that have replaced them.

Obsolete Service	Current Service
$BRDCST	$BRKTHRU, $BRKTHRUW
$CHANGE_ACL	$GET_SECURITY, $SET_SECURITY
$CNTREG	$DELTVA
$CRELOG	$CRELNM
$DELLOG	$DELLNM
$GETCHN	$GETDVI, $GETDVIW
$GETDEV	$GETDVI, $GETDVIW
$INPUT	$QIO, $QIOW
$OUTPUT	$QIO, $QIOW
$SETSFM	This service is still supported but its use is discouraged.
$SETSSF	This service is still supported but its use is discouraged.
$SNDACC	$SNDJBC, $SNDJBCW
$SNDSMB	$SNDJBC, $SNDJBCW
$TRNLOG	$TRNLNM

Copyright © Compaq Computer Corporation 1998. All rights reserved. Legal

4527PRO_098.HTML