Linden Lab Official:Media Plugin System Internal Messages

Media Rendering Plugin System

• Frequently Asked Questions
• Technical Overview
• Using the Plugin Test App
• Getting Started
  • Hello World Plugin Code
• Plugin Operation and Data Flow
• Messages
  • Internal Messages

The Viewer and each plugin loader shell (PLS) exchange internal system messages. Plugins do not need to handle these messages. This documentation is provided here for Viewer developers and for general reference purposes.

Messages plugin loader shell sends

hello

This is the first message the plugin loader shell sends to the Viewer when it initializes.

load_plugin_response

This message indicates the plugin is loaded and initialized.

Parameters

Key	Type	Description
versions	Map	Lists version corresponding to each plugin class. Key: message class name Value: version string. All versions start at "1.0".
plugin_version	String	Free-form version string for the plugin. This is expected to contain the versions of libraries the plugin uses (for example, quicktime, webkit, and so on) and may end up in the Viewer's about box.

heartbeat

Plugin loader shell sends these once per second to indicate that the plugin isn't locked up.

Parameters

Key	Type	Description
cpu_usage	Float	Approximate fraction of a single CPU the plugin has used for the interval since the last heartbeat message (0.0 means no usage, 1.0 means the plugin kept one CPU completely busy for the entire interval). This number may go above 1.0 on multi-core machines.

shm_add_response

This message indicates shared memory has been mapped into the child.

Parameters

Key	Type	Description
name	String	?

shm_remove_response

Plugin is done with the shared memory segment, safe to delete.

Parameters

Key	Type	Description
name	String	?

Messages plugin loader shell receives

load_plugin

Tells the loader to load a plugin and send the base init message.

Parameters

Key	Type	Description
file	String	Full path to the plugin DLL/dylib/so file.

shm_add

shared memory segment has been set up in the parent

Parameters

Key	Type	Description
name	string	?
size	S32	?

shm_remove

Shared memory segment will be removed once you respond

Parameters

Key	Type	Description
name	String	Name of shared memory segment to remove.

sleep_time

Set the interval between idle messages to the plugin.

Parameters

Key	Type	Description
time	Float	Time in seconds (default is 1/100)