Cs 290: Collaborative Systems 1 Section 3: Collaborative Infrastructures

processes ! View processes for fairness These enforced Centralized impl only ALV for replicated Clock No side e ects Pure functional Structured objects Centralized implem root object Session object model object view component obj session prede ned allUsers userName userScreen removeUser addUser root view view Views map greetingView allUsers GreetingView view Window userName myId userScreen myId Text greeting display text IP address displayView key KeyCode modifyGreeting KeyCode GreetingModel greeting this modifyGreeting KeyCode save new greeting initially save hello world Program consists of hierarchical components Root view View components have display view ! controller Model request method ! update methods Hierarhical scopes scopes uses IS PART OF relationship messages can only be sent to parent constraints ow downwards so no cycles support for transactions user actions create a series of threads user actions oredered orders their threads orders accesses to resources server based locking Views execute in local processes Distribution schemes Naive change noti ed request response Request Cache cache responses if cached value not changed use cache server invalidates cache based on data ow techniques seven times improvment Request Prefetech get all invalid values in batch speedup to times Request Presend Server remembers which values requested by each view sends these values when it invalidates speedup MUDS Room based session man Colab Programming Environment Broadcast Methods Replicated WYS INWYS Shared User Interfaces GroupKit Sharedd Environments etc broadcast methods " noti cation multicast rpcs lexible session mgmt XTV Shared Windows Colab Transparency