From ed78bbe5ba12be1f9bcc736f14c51da6b4f639f3 Mon Sep 17 00:00:00 2001 From: David Robillard Date: Wed, 8 Feb 2012 04:56:24 +0000 Subject: Rearrange tree so top level can be used as an include path for standard style LV2 includes. --- lv2/lv2plug.in/ns/ext/contexts/contexts.ttl | 134 ++++++++++++++++++++++++++++ 1 file changed, 134 insertions(+) create mode 100644 lv2/lv2plug.in/ns/ext/contexts/contexts.ttl (limited to 'lv2/lv2plug.in/ns/ext/contexts/contexts.ttl') diff --git a/lv2/lv2plug.in/ns/ext/contexts/contexts.ttl b/lv2/lv2plug.in/ns/ext/contexts/contexts.ttl new file mode 100644 index 0000000..c56c649 --- /dev/null +++ b/lv2/lv2plug.in/ns/ext/contexts/contexts.ttl @@ -0,0 +1,134 @@ +# LV2 Contexts Extension +# +# Allows for an LV2 plugin to have several independent contexts, each with its +# own run callback and associated ports. +# +# Copyright (C) 2007-2010 David Robillard +# +# Permission is hereby granted, free of charge, to any person obtaining a +# copy of this software and associated documentation files (the "Software"), +# to deal in the Software without restriction, including without limitation +# the rights to use, copy, modify, merge, publish, distribute, sublicense, +# and/or sell copies of the Software, and to permit persons to whom the +# Software is furnished to do so, subject to the following conditions: +# +# The above copyright notice and this permission notice shall be included +# in all copies or substantial portions of the Software. +# +# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL +# THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR +# OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, +# ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR +# OTHER DEALINGS IN THE SOFTWARE. + +@prefix ctx: . +@prefix lv2: . +@prefix rdf: . +@prefix rdfs: . +@prefix xsd: . +@prefix doap: . +@prefix foaf: . + + + a lv2:Specification , lv2:Feature ; + doap:name "LV2 Contexts" ; + doap:shortdesc "Support for plugins with several execution contexts." ; + lv2:documentation """ +

An extension for LV2 plugins which have several execution contexts.

+ +

Contexts allow plugins to run tasks and/or process input/output in +multiple threads. Contexts can be used to add non-realtime functionality +to a plugin while still keeping the audio run() method realtime safe.

+ +

A context is an LV2 feature, so the usual LV2 feature mechanism is used +to determine whether a plugin has a given context, and whether or not it is +mandatory.

+ +

Unless otherwise stated, each context (defined by some URI) adds a new +threading class similar to the Audio class defined by LV2. Each context has a +run callback and a connect_port callback both in the same class (i.e. can't be +called concurrently), but may be called concurrently with functions for other +contexts (excluding the Instantiation class). Context properties such as +ctx:hardRTCapable apply to both functions. +The host MUST only call the correct connect_port function associated with the +context for that port, i.e. it is an error to use the main LV2 connect_port +function on a port with a context other than the main LV2 run function.

+""" . + + +########################## +## Context Base Classes ## +########################## + +ctx:Context a rdfs:Class ; + rdfs:label "LV2 Context" ; + lv2:documentation """ +

A potentially concurrent context (callback) on a plugin.

+ +

Ports are always associated with a context. If a port has no explicit context +property, then its context is ctx:audioContext (the default LV2 run() context).

+ +

A plugin indicates support for a context by supporting an LV2 Feature with +that context's URI. If a plugin optionally supports a context (e.g. +<plugin> lv2:optionalFeature ctx:idleContext .), then +all ports associated with that context MUST be lv2:connectionOptional. Thus, +hosts that do not support contexts will connect such ports to NULL and the +plugin can run with only a standard LV2 run() context.

+ +

Any plugin that supports any context (optionally or mandatorily) MUST adhere +to the following additional threading rules for LV2_Descriptor.connect_port:

+
    +
  • connect_port MUST only be called for a given port from the context +associated with that port
    • +
  • connect_port MAY be called concurrently for ports with different +contexts (but MUST NOT be called concurrently for multiple ports in the +same context)
    • +
+

Note this implies that any shared data access in connect_port may be +accessed concurrently. The plugin is responsible for any synchronisation +or locking necessary to make this possible.

+""" . + +ctx:audioContext a ctx:Context , lv2:Feature ; + rdfs:comment """The context of LV2_Descriptor.run().""" . + +ctx:messageContext a ctx:Context , lv2:Feature ; + lv2:documentation """ +

A non-realtime context for plugin control via message passing. This context +has a run method which takes a bitset of flags for parameters specifying which +input and output ports are valid before and after the run method has executed, +respectively (see LV2_Contexts_MessageContext).

+""" . + +ctx:idleContext a ctx:Context , lv2:Feature ; + rdfs:comment """ +A non-realtime idle context, periodically run by the host roughly every second. +This context never has any ports. +""" . + +ctx:requestRunFeature a lv2:Feature ; + lv2:documentation """ +

A feature allowing the plugin to request the execution of a particular +context at an arbitrary time. To support this feature, the host MUST pass an +LV2_Feature to instantiate with data pointing to a +LV2_Contexts_Request_Run_Feature.

+ +

The plugin MAY call request_run with the given +data from any non-realtime context to demand soon-as-possible execution +of the specified context.

+""" . + +ctx:context a rdf:Property ; + rdfs:domain lv2:Port ; + rdfs:range ctx:Context ; + rdfs:label "is used in context" ; + rdfs:comment """ +The context a particular port is associated with; the port will only be +connected/read/written by that context. + +If no context is specified, the port is considered part of the default LV2 +audio context.""" . + + -- cgit v1.2.1