|
|
| (31 intermediate revisions by the same user not shown) |
| Line 1: |
Line 1: |
| − | author: [[User:Kr|Kr]] <br>
| + | Type: Specification State: draft Claim: optional |
| − | version: {{REVISIONID}} <br>
| |
| − | state: draft <br>
| |
| − | created: 12/12/2006 <br>
| |
| − | changed: 12/12/2006 <br>
| |
| − | type: specification <br>
| |
| | | | |
| | + | ==Feature== |
| | + | The [[../Runtime|Runtime]] provides dedicated support for implementing and handling |
| | + | * [[Uno/Term/Thread Safe|thread-safe]], |
| | + | * [[Uno/Term/Thread Unsafe|thread-unsafe]], and |
| | + | * [[Uno/Term/Thread Affine|thread-affine]] |
| | + | objects. The threading type of any code can be specified appropriately. |
| | | | |
| − | == UNO Threading Model == | + | ==Rationale== |
| | + | The [[Analysis/Multi-Threading| analysis of multi-threading]] shows OOo deficiencies wrt to multi-threading and [[Uno/Term/Thread Safe|thread-safeness]]. The [[Architecture/Goals for OOo Threading-Model&-Architecture|goals for the OOo Threading-Model & -Architecture]] identify three thread related types of code, which ([[Uno/Term/Thread Unsafe|thread-unsafe]], [[Uno/Term/Thread Safe|thread-safe]] and [[Uno/Term/Thread Affine|thread-affine]]). |
| | | | |
| | + | ==API== |
| | + | Two thread related purposes: |
| | + | * <code>":unsafe"</code> - for [[Uno/Term/Thread Unsafe|thread-unsafe]] code. |
| | + | * <code>":affine"</code> - for [[Uno/Term/Thread Affine|thread-affine]] code. |
| | | | |
| − | ; Feature: Abstract UNO Threading Model
| + | ==Dependencies== |
| − | : UNO Runtimes can provide support for simplifying implementing thread safe or thread affine code. Code can be differentiated into
| + | * [[Uno/Spec/Thread Affinity Bridge]] |
| − | : * client code
| + | * [[Uno/Spec/Thread Unsafety Bridge]] |
| − | : * component / object code
| + | * [[Uno/Spec/Purpose Environment]] |
| | + | * [[Uno/Spec/Environment Stack]] |
| | + | * [[Uno/Spec/Cascaded Mapping]] |
| | + | * [[Uno/Spec/Environment Substitution]] |
| | | | |
| − | : The UNO Threading Model allows code to leverage external locking, respectively to leverage thread specificy.
| |
| | | | |
| − | : For that to work, code has to decide to use one of three threading models: | + | [[Category:Draft]] |
| − | : * thread safe
| + | [[Category:Spec]] |
| − | : * thread unsafe
| + | [[Category:Uno]] |
| − | : * thread affine | + | [[Category:Uno:Spec]] |
| − | | + | [[Category:Multi-Threading]] |
| − | : The Free Threading Model | |
| − | : # code needs to take care of any threading issues, e.g. as locking critical sections etc. | |
| − | | |
| − | : This model should be leveraged for code doing blocking system calls, while providing an API for interruption. This model may also be used if a high degree of concurrency is needed, while one wants to eliminate any kind of apartment overhead. | |
| − | | |
| − | : The Thread-Unsafe Model | |
| − | : # code does not need to take care of any locking issues
| |
| − | : # code running in the Unsafe Thread Model is guaranteed to only be invoked once paralell per runtime.
| |
| − | : # code needs to take care of any thread affinity, means that code may be called by different threads alternately.
| |
| − | | |
| − | : This should become the standard model of implementation. Ensuring all code to be in this Model and utilizing only one thread should give optimal performance without any threading overhead.
| |
| − | | |
| − | : The Affine Thread Model
| |
| − | : * Is the as in the Unsafe Thread Model, while deleting -3-
| |
| − | : * Code in the Affine Thread Model can rely on being called by the same thread always.
| |
| − | | |
| − | : The Affine Thread Model is e.g. very usable for programming Windows thread affine APIs, e.g. OLE or WIN32.
| |
| − | | |
| − | : The programming counterpart for a threading model is the so called apartment.
| |
| − | | |
| − | : The different Threading Models are to be implemented via UNO environments being backed by apartments. A UNO Threading Model supporting UNO Runtime needs to provide:
| |
| − | : * threading model specific environment access (e.g. uno:mutex or java:thread)
| |
| − | : * an API for accessing the current apartment (the threading model)
| |
| − | : * an API for accessing the default apartments (mutex, thread, free)
| |
| − | | |
| − | : The apartments need to provide APIs for:
| |
| − | : * getting the name of an apartment
| |
| − | | |
| − | | |
| − | : Apartments Access Characteristics
| |
| − | | |
| − | : The different threading model specific apartments have different access characteristics, derived from the backing apartments:
| |
| − | | |
| − | : Free
| |
| − | : * Has no (threading) restrictions.
| |
| − | | |
| − | : Mutex Apartment
| |
| − | : * Can only be entered by one thread at a time.
| |
| − | : * Keepy being entered, even if the thread calls into another apartment.
| |
| − | : * Can be re-entered by a thread.
| |
| − | | |
| − | : Thread Apartment
| |
| − | : * Inherits the Mutex apartment attributes.
| |
| − | : * Has an associated thread.
| |
| − | : * All encapsulated objects only become called by the associated thread.
| |
| − | : * Blocks the entering thread and switches to the associated thread, passes along all parameters
| |
| − | : * Relieves the entering thread when the associated thread has executed the desired method. Passes back all results.
| |
| − | : * Switches back to the entering thread, in case an outside object should be called, passes along all parameters.
| |
| − | : * Switches back to the associated thread, when comming back from an outside call, passes back all results.
| |
