Two N -order square matrix A and B phase multiplication procedures with java, and the result is stored in square matrix C.Among them, use the Runnable interface to implement the matrix multiplication

The initial values of。

Fang Array A and B are as follows: (two threads at the same time)

Output: the sum of all elements in C, the execution time of the program

The specific program is as follows:

package com.xing.matrix; 

 /** 
  * 
  * @Author yinxing 
  * 
  */ 
 public class matrixmul { 

 Public Static Void Main (String [] args) Throws InterruptedException { 
 // Todo Auto-Generatd Method Stub 
 int i, j, t = 0; 
 int leng = 1500; 
 Long Starttime, Endtime; 
 long a [] [] = new long [long] [length]; 
 long b [] [] = new long [long] [length]; 
 // -------------- to initialize matrix A and matrix B -------------- 
 for (i = 0; I <lang; i ++) 
 {{ 
 t = i+1; 
 for (j = 0; j <lang; j ++) 
 {{ 
 a [i] [j] = t ++; 
 b [i] [j] = 1; 
 } 
 } 
 Matrix matrixone = new matrix (a, b, 0, length); 
 Matrix matrixtwo = New Matrix (a, B, 1, Leng); 
 Thread Threadone = New Thread (Matrixone); 
 Thread ThreadTwo = New Thread (MatrixTwo); 
 		//-------------------Parallel Computing-------------------- 
 starttime = System.currenttiMillis (); 
 threadone.start (); 
 threadtwo.start (); 
 threadone.Join (); 
 threadtwo.Join (); 
 endtime = System.currenttiMillis (); 
         System.out.println ("Parallel result =" + (matrixone.getsum () + matrixtwo.getsum ());); 
         System.out.println ("" parallel time = " + (endtime -starttime)); 
         // -------------------------------------------------- 
         starttime = System.currenttiMillis (); 
         Matrix matrixThree = New Matrix (a, B, 0, Leng); 
         matrixThree.serial (); 
         endtime = System.currenttiMillis (); 
         System.out.println ("serial result =" + matrixThree.getsum ()); 
         System.out.println ("serial time =" + (endtime -starttime)); 
 } 
 } 
 Class Matrix Implements Runnable { 

 Private long a [] []; 
 Private long b [] []; 
 Private long c [] []; 
 Private int Start; 
 Private int end; 
 Private Long Sum = 0; 
 
 public matrix (long a [] [], long b [] [], int, int en) { 
 this.a = a; 
 this.b = b; 
 this.start = ST; 
 this.end = en; 
 this.c = new long [en] [en]; 
 } 
 @Override 
 public void run () { 
 // Todo Auto-Generatd Method Stub 
 int i, j, k; 
 for (i = start; i <end; i += 2) 
 {{ 
 for (J = 0; J <END; J ++) 
 {{ 
 C [i] [j] = 0; 
 for (k = 0; k <end; k ++) 
 {{ 
 C [i] [j]+= a [i] [k]*b [k] [j]; 
 } 
 } 
 } 
 
 for (i = start; i <end; i+= 2) 
 for (J = 0; J <END; J ++) 
 sum += c [i] [j]; 
 } 
 
 Public void server () {// serial calculation of a matrix multiplication and then seeking 
 int i, j, k; 
 for (i = 0; i <h; i ++) 
 {{ 
 for (J = 0; J <END; J ++) 
 {{ 
 C [i] [j] = 0; 
 for (k = 0; k <end; k ++) 
 {{ 
 C [i] [j]+= a [i] [k]*b [k] [j]; 
 } 
 } 
 } 
 for (i = 0; i <h; i ++) 
 for (J = 0; J <END; J ++) 
 sum += c [i] [j]; 
 } 
 public long getsum () { 
 Return this.sum; 
 } 
 }

Run results as follows:(Among them, the use of multi -nuclear combined parts is multiplication and demand)

relative acceleration ratio is: 58692/32020 = 1.832979387882573