CSS490 M++ Textbook No Corresponding Chapter

1. CSS490 M++ Textbook No Corresponding Chapter Instructor: Munehiro Fukuda These slides were thoroughly the instructor’s original materials. CSS490 M++

2. Thread Migrationoverview • Moving: • CPU status • Stack • (Heap) Migrating a thread Memory access Memory access Distributed Shared Memory (in most cases) Local memory Local memory Local memory Actual memory access with high latency LAN/SAN CSS490 M++

3. Thread MigrationExamples CSS490 M++

4. M++ • Mobile Agents • Merits: Inherent parallelism and multi-agent-base applications • Demerit: Performance problem because of their interpretation • Thread Migration • Merit: Fast migration • Demerits:DSM needed and No navigational autonomy • Logical Network • Global application-specific network • Constructed at run time • Node data referred to after migrating that node. • Extension of C++ Language • Agent encapsulated by object-oriented language • Navigational autonomy with strong migration CSS490 M++

5. Multi-Agent Approach Simulate the interaction among agents Advantages: • Overcomes the limitations of mathematical techniques • Encapsulates simulation models • Allows open-ended simulation Disadvantages: • Performance • Parallel programming CSS490 M++

6. Object Queue Object Queue Obj 5 Obj 6 Obj 2 Obj 3 Obj 4 Obj 4 Obj 6 Obj 3 Obj 2 Obj 1 Obj 1 Obj 5 null null Exchange Parallelizing Multi-Agent Application with MPI • MPI Process must • maintain each agent as a static object • maintain as a simulation space a two-dimensional array • change each status periodically • exchange them with remote processes • Synchronize with remote processes Process 2 Process 1 Obj 7 LAN/SAN CSS490 M++

7. Parallelizing Multi-Agent Application with Mobile Agent • We don’t need a control process! • Each simulation entity works independently as an agent. agent Shark { Shark( ) { … } void run( ) { while (alive) { compute( ); go( ); } } } LAN/SAN CSS490 M++

8. Performance Problem • Mobile Agents: • They were cognitive agents designed to perform large remote jobs. • They are code in Java and Tcl, and thus interpreted. • Their size is so big and their speed is so slow. • Performance Improvement: • Self-migrating threads • Zero-copy migration library CSS490 M++

9. M++ Execution Model 1 Logical Network hop(1@2) Node create Node with 3@2 Link Link 3 1 1 Thread Node Node Node Daemon Network 1 2 3 Daemon Daemon Daemon Physical Network LAN/SAN CSS490 M++

10. M++ Language Overview class Node {// Defining nodes (and links) as C++ classes public: int var; }; thread Thread { // Defining an M++ thread private: main() { // Executing its own behavior independently create node<Node> with 1; // Creating a network node, (link, and thread) hop( 1 ); // Migrating itself (and forking) node<Node>.var = 10; // Accessing the current node, (and link) } }; CSS490 M++

11. M++ Compilation Includes three pieces of agent code • Source program • must have an mpp extension. • may include two or more agent code. • The mpp compiler • first preprocesses the source code into C++ files, each corresponding to a different agent. • pass them to the g++ compiler, and generates executable files, each again corresponding to a different agent. m++@MEDUSA[16]% ls Car.mpp profile m++@MEDUSA[17]% m++ Car.mpp ***** compiling GSCashier ***** compiling SportsCar ***** compiling Truck m++@MEDUSA[18]% ls Car.mpp GSCashier* SportsCar* Truck* profile m++@MEDUSA[19]% Compile it with the m++ compiler Message printed out from m++ Three executable files obtained CSS490 M++

12. M++ Profile m++@MEDUSA[21]% cat profile port 10145 hostnum 4 mode sthread describe daemonid medusa 0 mnode1 1 mnode2 2 mnode3 3 describe_end m++@MEDUSA[22]% CSS490 M++

13. M++ Daemon Invocation m++@mnode3[4]% nohup thrd& exit [1] 6659 logout rlogin: connection closed. m++@mnode2[3]% nohup thrd& exit [1] 6678 logout rlogin: connection closed. m++@mnode1[3]% nohup thrd& exit [1] 8200 logout rlogin: connection closed. m++@MEDUSA[10]% thrd& [1] 4954 port : 10145 Connction established to medusa with daemon 0 Connction established to mnode1 with daemon 1 Connction established to mnode2 with daemon 2 Connction established to mnode3 with daemon 3 Total daemon(s) : 4 Mode : sthread Stack : 65536 byte Ready for being injected. m++@MEDUSA[11]% • Run “thrd” on each PC • Open a new window for each PC and type thrd, OR • Remotely login each PC and type “nohup thrd&” • All thrd print out “ready for being injected” • You are ready to launch new m++ threads. CSS490 M++

14. M++ Thread Launching m++@MEDUSA[11]% inject medusa ./GSCashier 1 Injected 1 ./GSCashier thread(s) to medusa m++@MEDUSA[12]% GSCashier: Waiting for cars. m++@MEDUSA[12]% inject medusa ./Truck 1 Injected 1 ./Truck thread(s) to medusa m++@MEDUSA[13]% Truck: I'm at the GasStation. GSCashier: Injected fuel to Truck Diesel: 900 Regular: 1000 GSCashier: Waiting for cars. Truck: I'm filled with fuel. m++@MEDUSA[13]% fg thrd thrd: Interrupted. thrd: Closed all connections. thrd: Terminated. m++@MEDUSA[14]% • To launch a M++ thread, type • Inject target_IPname executable_file #threads arguments • To stop the M++ system • Bring back one of thrds to foreground and type cntl+c CSS490 M++

15. M++ Language in DetailsThread Definitions and Deployment thread Child { // spawned by a Parent thread public: Child(int argc, const char** argv):id( atoi(argv[5])){ strncpy(msg, argv[4], 16 ); } void main() { cout << msg << id << endl; } private: char msg[16]; int id; }; thread Parent { // injected first public: void main( ); private: int i; char idstr[10]; }; void Parent::main( ) { for (i=0; i<10; i<++ ) { // spawn 10 Child threads sprintf(idstr, “%d”, i); create thread<Child>(“I am Thread No”, idstr); } } • A thread constructor receives arguments starting from argv[4] • A thread immediately starts its own execution in main( ). CSS490 M++

16. M++ Language in DetailsNetwork Components CSS490 M++

17. 1 20 Path 10 Place M++ Language in DetailsLogical Network Construction • Node creation and destruction • [e]create node<NodeClassName>(argsList) with (NodeId[@DaemonId]); • [e]destroy node(NodeId[@DaemonId]); • Link creation and destruction • [e]create link<LinkClassName>(argsList) with (SrcLinkId) to (NodeId[@DaemonId] with (DestLinkId) • [e]destory link(srcLinkId); • Only available in thread main( ) 0 Init class Place { }; class Path { }; thread Net { public: void main( ) { create node<Place>( ) with( 1@1 ); create link<Path>( ) with(10)to(1@1) with(20); } } 1 0 Daemon Daemon CSS490 M++

18. hi! hi! 1 20 Path 10 Place M++ Language in DetailsNetwork Navigation • [e]hop( [NodeId@DaemonId] ); • [e]hopalong( srcLinkId ); • [e]fork([ NodeId@DaemonId] ); • [e]forkalong( srcLinkId ); 0 Init class Place { }; class Path { }; thread Net { public: void main( ) { create node<Place>( ) with( 1@1 ); create link<Path>( ) with(10)to(1@1) with(20); hop( 1@1 ); hopalong( 20 ); forkalong( 10 ); cout << “hi!” << endl; } } 1 0 Daemon Daemon CSS490 M++

19. Thread 2 Thread 1 Place write read var Daemon M++ Language in DetailsInter-Thread Communication • Indirect communication: threads can read and write the same variable on the same node. • Thread 1 hop( node3@daemon1 ); node<Place>.var = 10; • Thread 2 hop( node3@daemon1 ); myVar = node<Place>.var; • Direct communication: A thread can access another thread directly. • Thread 1 reads Thread2 myVar = Thread[2].myVar; • Thread 2 writes Thread1 Thread[1].myVar = myVar; Direct myVar myVar Indirect CSS490 M++

20. M++ Language in DetailsThread Synchronization • Nodes are monitors • Unless a thread executes a network construction or a migration statement, it can continuously and exclusively run on the current node. • Synchronization statements • sleep: suspends until “wakeup threadId” or “wakeupall”. • sleep node: suspends until “wakeup[all] node”. • sleep daemon: suspends until “wakeup[all] daemon”. • wakeup threadId: resumes the thread with threadId. • wakeup node: resumes one thread sleeping on node. • wakeup daemon: resumes one thread sleeping on daemon. • wakeupall node: resumes all threads sleeping on node. • wakeupall daemon: resumes all threads sleeping on daemon. CSS490 M++

21. ImplementationState Capturing Thread Thread UsrClass thrvar; thread Thread { main() { : hop(); : } }; UsrClass thrvar; thread Thread { main() { : hop(); : } }; 200 Execution 200 Resume New pointer Pointer UsrClass thrvar; 200 UsrClass thrvar; 200 Old pointer Pointer Copy constructor Dst Daemon Src Daemon Virtual function table Virtual function table Transfer CSS490 M++

22. Main Main A A B B C C 1 2 1 A C A B C A B C Main C Main ImplementationThread Scheduling Sthread Library Pthread Library User level Kernel level 1: 1: 2: CSS490 M++

23. Thread 2 Thread 3 ImplementationZero-copy communication Receiver Sender User Area User Area Pin-downed pages Thread 1 Thread 1 (2) Thread 2 Thread 2 (3) gather scatter Thread 3 Thread 3 Immediate resumption Packed Threads Packed Thread Kernel Area Kernel Area RAM RAM (1) Zero-copy transfer Network Interface Network Interface CSS490 M++

24. Exercises (No turn-in) • Consider the pros and cons of MPI and M++ when used to design a multi-agent application. • Why and when is thread migration necessary? • What is zero-copy communication? Why is it so effective? CSS490 M++

25. Final Project • Find a parallel application and program in both MPI and M++. • Compare their programmability and performance. • You may have a partner. One codes an MPI version, the other M++ version. • Exclude the following applications (already programmed): • Antfarm • Artificial societies • Growing neural network • Matrix multiplication • Mandelblot CSS490 M++