Haskell、C#、Java、C 程式執行效率比較 ：Write your first parallel Haskell program

from: http://www.haskell.org/haskellwiki/Haskell_in_5_steps#Write_your_first_parallel_Haskell_program

起由: Write your first parallel Haskell program

Haskell has good support for parallel and multicore programming. We can write a parallel program by adding `par` to expressions, like so:

import Control.Parallel main = a `par` b `par` c `pseq` print (a + b + c)    where        a = ack 3 10        b = fac 42        c = fib 34 fac 0 = 1fac n = n * fac (n-1) ack 0 n = n+1ack m 0 = ack (m-1) 1ack m n = ack (m-1) (ack m (n-1)) fib 0 = 0fib 1 = 1fib n = fib (n-1) + fib (n-2)

　　

編譯運行：

--------多核版本-----------------------------------$ ghc -O2 -o mcore.exe --make mt.hs -threaded -rtsoptsLinking mcore.exe ...Administrator@SPARK d:/workspace/Haskell$ time mcore +RTS -N21405006117752879898543142606244511569936384005711076real    0m1.812suser    0m0.000ssys     0m0.031s--------單核版本-----------------------------------Administrator@SPARK d:/workspace/Haskell$ ghc -O2 -o score.exe --make mt.hs -rtsoptsLinking score.exe ...Administrator@SPARK d:/workspace/Haskell$ time score +RTS1405006117752879898543142606244511569936384005711076real    0m2.406suser    0m0.000ssys     0m0.000s----------------------------------------------------

　　

運行在win32 + Git Bash。

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之後又在java和c#中執行效率相比較一下：

C#版本：

using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading;using System.Diagnostics;namespace CompareMulticore{        class Program    {        static double fac(double n)        {            return n == 0 ? 1 : n * fac(n - 1);        }        static double ack(double m, double n)        {            if (m == 0) return n + 1;            if (n == 0) return ack(m - 1, 1);            return ack(m - 1, ack(m,n-1));        }        static double fib(double n)        {            if (n == 0 || n == 1) return n;            return fib(n - 1) + fib(n - 2);        }        static void Main(string[] args)        {            // Create new stopwatch            Stopwatch stopwatch = new Stopwatch();            // Begin timing            stopwatch.Start();            // Do something            double u1 = ack(3, 10);            double u2 = fac(42);            double u3 = fib(34);            Console.WriteLine(u1 + u2 + u3);            // Stop timing            stopwatch.Stop();            // Write result            Console.WriteLine("Time elapsed: {0}",stopwatch.Elapsed);            Console.ReadKey();        }    }}

　　採用release編譯後運行，直接在資源管理員裡雙擊運行：

C# Release Any CPU版本運行結果約為:

1.40500611775288E+51

Time elapsed: 00:00:00.9070211

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java版本：

//StopWatch.javapublic class StopWatch { private long startTime = 0;    private long stopTime = 0;    private boolean running = false;        public void start() {        this.startTime = System.currentTimeMillis();        this.running = true;    }        public void stop() {        this.stopTime = System.currentTimeMillis();        this.running = false;    }        //elaspsed time in milliseconds    public long getElapsedTime() {        long elapsed;        if (running) {             elapsed = (System.currentTimeMillis() - startTime);        }        else {            elapsed = (stopTime - startTime);        }        return elapsed;    }            //elaspsed time in seconds    public long getElapsedTimeSecs() {        long elapsed;        if (running) {            elapsed = ((System.currentTimeMillis() - startTime) / 1000);        }        else {            elapsed = ((stopTime - startTime) / 1000);        }        return elapsed;    }    }//Test.javapublic class Test { static double fac(double n)     {         return n == 0 ? 1 : n * fac(n - 1);     }     static double ack(double m, double n)     {         if (m == 0) return n + 1;         if (n == 0) return ack(m - 1, 1);         return ack(m - 1, ack(m,n-1));     }     static double fib(double n)     {         if (n == 0 || n == 1) return n;         return fib(n - 1) + fib(n - 2);     }/** * @param args */public static void main(String[] args) {// Create new stopwatch        StopWatch stopwatch = new StopWatch();        // Begin timing        stopwatch.start();        // Do something        double u1 = ack(3, 10);        double u2 = fac(42);        double u3 = fib(34);        System.out.println(u1 + u2 + u3);        // Stop timing        stopwatch.stop();        System.out.println("elapsed time in milliseconds: " + stopwatch.getElapsedTime());}}

　　

命令列編繹後運行結果約為:

$ java  -Xms512M -Xmx1024M  -Xss100M Test

1.4050061177528798E51

elapsed time in milliseconds: 843

注意：運行選項，預設為：

-Xms40m

-Xmx512m 出現

Exception in thread "main" java.lang.StackOverflowError

at Test.ack(Test.java:13)

故需要更改VM選項。 /*******************************************************************************/再用C語言gcc編譯器

#include <stdio.h>#include <stdlib.h>#include <time.h> double fac(double n){    return n == 0 ? 1 : n * fac(n - 1);} double ack(double m, double n){    if (m == 0) return n + 1;    if (n == 0) return ack(m - 1, 1);    return ack(m - 1, ack(m,n-1));} double fib(double n){    if (n == 0 || n == 1) return n;    return fib(n - 1) + fib(n - 2);}int main(){    //time_t start,end;    //double dif;    //time (&start);    double u1 = ack(3, 10);    double u2 = fac(42);    double u3 = fib(34);    printf("%f",u1 + u2 + u3);    //time (&end);    //printf ("\nIt took you %.2lf seconds to do this.\n", dif );    //printf("Press Enter to exit.");    //getchar();    return 0;}

windows server 2003安裝http://stackoverflow.com/questions/673523/how-to-measure-execution-time-of-command-in-windows-command-line

Windows Server 2003 Resource Kit Tools

http://www.microsoft.com/download/en/details.aspx?DisplayLang=en&id=17657在 cmd中執行：D:test\CB\CompareLang\bin\Release> timeit CompareLang.exe 1405006117752880000000000000000000000000000000000000.000000 Version Number:   Windows NT 5.2 (Build 3790) Exit Time:        12:01 am, Friday, October 21 2011 Elapsed Time:     0:00:00.937 Process Time:     0:00:00.937 System Calls:     12537 Context Switches: 10635 Page Faults:      466 Bytes Read:       2564 Bytes Written:    2540 Bytes Other:      2306

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最終結果:

java 略勝一籌。

C#.net次之.

C 第三 （意外，居然沒有java,c#快）

Haskell多核版本第四。

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附java運行選項解釋：

http://publib.boulder.ibm.com/infocenter/javasdk/tools/index.jsp?topic=%2Fcom.ibm.java.doc.igaa%2F_1vg000131402ee-11e49e6e566-7fda_1001.html

Resolving a native stack overflow

Information to diagnose and resolve a stack overflow.

Introduction

The two main causes of stack overflow are as follows:

• Infinite recursion is occurring in the application.
• There is insufficient stack size for application.

Read the information below to determine which problem is occurring and how to resolve the issue.

Determining if the problem is infinite recursion or insufficient stack size

Infinite recursion is the most common cause of stack overflows. This problem occurs when a single method or function, or several methods or functions, are called repeatedly. The Just-In-Time (JIT) Compiler uses optimization to try to prevent a stack overflow when a single Java method is called repeatedly. The most common cause of infinite recursion in a Java application is the use of repeated patterns of Java methods or repeated calls to C functions.

To determine if infinite recursion has taken place, look at the stack trace for the thread that overflowed. In this way, you can identify repeating C function calls or patterns of Java methods. Use this information to check the repeated code for errors that might cause the infinite loop.

A large stack might be required if the repeated pattern of functions or methods is processing a large data artefact, such as an XML Document Object Model (DOM). In this case, increase the native stack size using the -Xmso command-line option in Java.

Resolving the problem

If you are unsure whether the problem is caused by infinite recursion or insufficient stack size, try increasing the native stack size to see if an increase prevents the problem.

Find the current stack size by running the following command line option to Java:

  -verbose:sizes

This command prints out the value of various memory size settings. Here is the output for 32-bit Windows:

 -Xmca32K        RAM class segment increment   -Xmco128K       ROM class segment increment   -Xmns0K         initial new space size   -Xmnx0K         maximum new space size   -Xms4M          initial memory size   -Xmos4M         initial old space size   -Xmox1500M      maximum old space size   -Xmx1500M       memory maximum   -Xmr16K         remembered set size   -Xmso32K        operating system thread stack size   -Xiss2K         java thread stack initial size   -Xssi16K        java thread stack increment   -Xss256K        java thread stack maximum size

This output shows an operating system thread stack size of 32 KB. Increase this value by a factor of two using the -Xmso command-line option.

If the problem remains after increasing the stack size, infinite recursion is probably the cause. Ask the owner of the code to analyze it for potential problems. Meanwhile, run the application with larger native stack sizes.