Parallel Programmingwith Java
YILDIRAY YILMAZ
Maltepe Üniversitesi
Message Passing Interface (MPI)
•MPI is a standard (interface or API)
•It defines a set of methods that are used by developers to write their application
•MPI library implement this method
•MPI itself is not a library. It is a specification document that is followed.
Message Passing Interface (MPI)
•Reasons for popularity
•Software and hardware vendors were involved
•Significant contribution from academia
•MPI compilers are widely used
•It is the mostly adopted programming paradigm of IBM Blue Gene Systems
Message Passing Interface (MPI)
•There is an open source Java message passing library
MPJ Express
•What is MPJ Express?
•MPJ Express is an open source Java message passing library that allows applicationdevelopers to write and execute parallel applications for multicore processors andcompute clusters/clouds. It is distributed under the MIT (a variant of the LGPL) licence.
MPJ Express
•The MPJ Express can be configured in two ways. The first configuration isMulticore Configuration. It is used to execute programs on laptops anddesktops. The second configuration is Cluster configuration. It is used toexecute programs on clusters or network of computers.
Multicore Configuration
Cluster Configuration
Steps involved in executing the ‘Hello World’ Javaprogram for multicore configurations in Windowswith Eclipse IDE
1.Download one of the Eclipse IDE version.
2.Download MPJ library
3.Create a new project on Eclipse IDE and configure the build path
4.Adjust run configurations
5.Write the Hello World program
6.Execute the parallel program
Step 1: Download the Eclipse IDE
Step 2: Download MPJ library
Step 3: Create a new project on Eclipse IDE andconfigure the buildpath
Step 3: Create a new project on Eclipse IDE andconfigure the buildpath
Step 4: Write the Hello World Program
Step 5: Adjust Run Configurations
•Click the «Run>Run Configuration» on Eclipse
•Switch to Environment Tab
•Click New
•Set the MPJ_HOME to Name Input
•Set the MPJ_HOME to Value Input (which is the path of MPJ home directory)
•Switch to Argument Tab
•Set the below line to VM Arguments’ text area
•-jar ${MPJ_HOME}/lib/starter.jar -np 4 (this line gives the process count to jvm)
Step 6: Run the Parallel Program
•Just right click your MPJ project and select the Run as Java Applicaton
Your console output will be like this:
Fibonacci
•0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, ...
•F(n) = F(n-1) + F(n – 2) with seed values F(0) = 0, F(1) = 1
Recursive Fibonacci Pseudo Code
function Fib(n)
if n <= 1 then
return n;
else
return Fib(n – 1) + Fib(n – 2)
end if
end function
Time Complexity of Recursive FibonacciSequence
•T(n <= 1) = O(1)T(n) = T(n – 1) + T(n – 2) + O(1)
•Time Complexity is O(2n)
Parallelized Fibonacci Pseudo Code
function Fib(n)
if n <= 1 then
return n;
else
x = spawn Fib(n – 1)
y = Fib(n – 2)
sync
return x + y
end if
end function
Time Complexity of Parallelized Fibonacci
•T(n) = max(T(n – 1), T(n – 2)) + O(1)T(n) = T(n – 1) + O(1)
•Time Complexity of parallel fibonacci is O(Ø^n/n)
Q & A
•Thanks...
Yıldıray YILMAZ