Mike's Tech Notes for 6/28/2012

ccr coordination primitivesasynchronous programming hard simple method coordinate between multiple operations deal partial failure one many fail others succeed define execution behavior asynchronous callbacks don't violate concurrency constraint example attempt something parallel runtime enables promotes providing ways express happen plus enforce high level constraints different code segments run due messages being received ports primitive thread spawn handler defined ccrservicebase couple additional overloads accept parameters pass lt t0 gt passes parameter type call times eventually use available threads free running amongst apart themselves it’s important realize relationship loose coupling fast initiation work consistent queues interaction software design scales well dependencies drawbacks mentioned above addressed appropriate model components primitives provided classified based two primary scenarios inbound requests long lived service oriented common web listening http network port post attaching handlers wake up serve each request independent addition uses advanced guarantee never active responses more outstanding possible return types per response waiting success portset associated pending completes item posted execute another scattering once collecting single caring order arrive arbiter described briefly followed detailed explanation context static classthe class provides helper routines creating instances classes discoverable safe manner methods below members exhaustive list arbiters constructed configurations directly constructor following shows created invoking fromtask creates instance taskarbiter choice choicearbiter receive receiverarbiter interleave interleavearbiter joinedreceive joinreceiverarbiter multipleitemreceive joinsingleportreceiverthe reference documentation used necessary extension methodsa concise alternative through new support examples guide extensions create receivers joins etc responseport easy way handle dss services expose portsets contain requested information fault whichever message sent back effectively waits same time executes corresponding delegate receives receivera receiver associates user takes persist option true false un register 7c var activate _taskqueue console writeline notice persisted until garbage collected abbreviated syntax anonymous statement called line print value experienced programmer older style â example 8c alternate version explicitly constructs passing factory persistedreceiver null predicate task exactly effect really thin wrapper around arbiterthe branches atomically step cant interrupted removes nested guarantees branch branching guard against race conditions 9c serviceport simpleservice getstate given found ex delegates note take arbitrary number receiversmultiple come categories known waitformultiple os literature attempts items wait try again right met phase logic deadlock mechanism atomic access resources without fear specified fixed compile fact join over forms typed eagerly remove participating total count satisfied very resource synchronization gathering results scatter gather joinsexample 10c portdouble portstring joined stringvalue tostring updated values matter power 14159 last 10 demonstrates activated posts determines everything needs schedules 11c portint second listen listens share contention intvalue 128 determine first allowing lost 11 previous showing case implementation both soon extracted shared races affect outcome basically traditional locking problem become scheduling dependency resolved guarded concurrent signal triggers requires 12c itemcount 12 dynamic â join stored variable read expected aggregate 13c exception requestcount send set respond failures successes 13 dealing assuming multipleitemreceiver gives arriving combination collections containing mutipleitemreceive discrete underlying multipleitemgather executed yield implicit activation need useâ arbiter inside iterator componentspersisted receiversccr motivated beginning capable efficiently executing process simplest mode whenever 14c summary base defines public serviceoperation stop updatestate state component abstract api _mainport dispatcherqueue _state taskqueue initialize private supplied three concurrently updatehandler getstatehandler external callers cache dispatcher queue schedule tasks demonstrate invalidoperationexception update field result itself 14 implementing pattern definitions interact definition derived accepts derive convenient reuse particular initializes returns communicate attaches talk exist arbiterfor non trivial carefully protected data structure internally requiring updates treated scenario complex multi preempted certain helps think care queueing activations complete declare protection require programmers familiar reader writer lock similar concept biased instead specific object sections avoiding internal manages exclusively 15c servicewithinterleave relation teardownreceivergroup teardown stophandler exclusivereceivergroup runs concurrentreceivergroup merge strings makes stopping 15 extends various parent youâ can concisely intent terms independently know exclusive protect later section steps writing subclass dsspservicebase automatically maininterleave furthermore added start mark servicehandler attribute see

use scattergather function var resultport activate dispatcherqueue 10 num gt above code fill bunch zeroes return instead fills up through makes sense variable analagous loop appears parameter passed zero didn't pass expect p0 numbers possibly out order ten example 1144330022is output one execution

tpl dataflow async await vs ccr part being cellfish site homewhile use data flow scatter gather patterns much same way actually enough once again thing need create number tasks wait task waitall method waitany you're interested first result short constant list keyword code formatted http manoli net csharpformat publicstatic lt gt fibonacciasync return var n1 n2 returnawait 10 remember common pattern want large success failure achieved depending report errors exceptions continue throw exception error occurs case returned flows suitable solution very ccrish done post back etc preventive comment technically above execute synchronously threads started real methods called important wanted show simple calling functions awaiting results needed