FREEVR DEBUG

NAME

FreeVR Debug levels — FreeVR's numeric values for configuring how much debugging info to output  

DESCRIPTION

The amount of debugging information that a running FreeVR virtual reality application outputs can be controlled by the configuration file in conjunction with a pair of environment variables. Most of the debugging output is geared toward debugging FreeVR itself, but there are settings to help debug VR configuration settings, and some for application debugging.  

Debug Values

Here is the list of debugging "topics", the built-in variables and the preset values:

CONFIGURATION

Tiered debugging output

• Tier 1 — Output all information at or below a particular level

The more general way to control debug and messaging output is by setting an overall "debug level". The value at which this parameter is set will allow all message levels at or below that value to be output. For example if the debug level is set to 40 (common), then any debug output for always, aalways, configerror, configwarn, spawn, and common will be output because each of these has a numeric value less than or equal to the numeric value of common.

In the configuration file, this is set as the DebugLevel parameter.

• Tier 2 — Output information at exactly a particular level

The overall goal for debugging output is to limit it to see values that will help highlight issues that need to be addressed (or to show that the system is operating normally). At times, of course, one may want to focus on a particular aspect of the running system to debug a specific aspect. In these cases, it is counter productive to set the level for something like debug:vruidd and have all the additional debugging information for all the other inputs and also the graphics rendering systems giving details of their operation that are not important to the task at hand.

To solve this, there is a mechanism to print one additional debug value on top of the less-than-or-equal-to values. In the configuration file, this is referred to as the DebugThisToo parameter.

Thus, when the system decides whether to output a particular debugging related message, it checks both whether the value is less-than-or-equal-to the value of DebugLevel or is exactly equal to the value of DebugThisToo.

Specifying values in the configuration

1)

Global configuration settings

   set DebugLevel = $debug:common;
   set DebugThisToo = $debug:parsedetail;

2)

System object settings

   system $system += { DebugLevel = $debug:seldom; }

3)

Process object settings

   process "joydev-input" += { DebugThisToo = $debug:joydev; }
   process "default-telnet" += { DebugThisToo = $debug:parse; }

4)

Environment variable settings

The following section describes the two environment variables that are used to set the debug output parameters run in a given terminal shell.

ENVIRONMENT VARIABLES

When a FreeVR application is executed, there are two environment variables in particular that affect the debugging information output:

FREEVR_DEBUGLEVEL_NO

Set level of debugging output that a FreeVR application will generate. Setting this value happens last, and thus none of the other means of reading configuration commands will override this setting — hence the NO (No Override) tag.

FREEVR_DEBUGEXACT_NO

Set an extra, exact level of debugging output that a FreeVR application will additionally generate, in addition to all messages at or below the general debug-level. Setting this value happens last, and thus none of the other means of reading configuration commands will override this setting — hence the NO (No Override) tag.

SEE ALSO

freevrrc(5FV), freevr(7fv),

The FreeVR web site:

http://www.freevr.org

LOCATION

The debug values are set in the source code "vr_debug.h" file, and the mapping of those values to built-in "variables" is in the "vr_debug.c" source file.

COPYRIGHT

Copyright 2024, Bill Sherman, All rights reserved.

Index

NAME

DESCRIPTION

Debug Values

CONFIGURATION

Tiered debugging output

Specifying values in the configuration

ENVIRONMENT VARIABLES

SEE ALSO

LOCATION

COPYRIGHT