Uno/Spec/Threading-Model

author: Kr
version: 8163
state: draft
created: 12/12/2005
type: specification

UNO Threading Model

Feature

The UNO Runtime provides support for implementing

• Thread Safe, or
• Thread Unsafe, or
• Thread Affine

Code.

The threading type of any code can be specified appropriately. The Thread Unsafe type is the default type for any implementation.

Rationale

API

Purpose UNO Environments: The different threading models are accessible as standard UNO environments (CPP: uno/environment.h). Environment specifications (e.g. "gcc3", "java") are extended by "purpose" specifiers (e.g. ":mutex", ":thread"), purpose specifiers may be chained (e.g. ":mutex:debug:test").

The predefined purposes to objects according to their threading type are

• ":mutex" - for thread unsafe code,
• ":thread" - for thread affine code, and
• "" - for thread safe code, to ensure compatibility with previous UNO versions.

Stacked Environments: The current (purpose) environment does not only vary with the implementation language (e.g. Java or C++), but also with the executed codes declared threading type. Therefor an API for accessing the current environment is provided.

Cascaded Mappings: Purpose environments may be passed to the Runtime for getting cascaded mappings ("gcc3" => "java:mutex:debug").

Implementation Environments: Client code as well as service code may be declared once, to either be thread safe, thread affine or thread unsafe.

Dependencies

Thread Environment

Mutex Environment

Cascaded Mapping

Compatibility Issues

None.