DPaste - Paste #359 - pastebin, online compiler and collaboration tool dedicated to D Programming Language

Concurrency test

Code

import std.array;
import std.algorithm;
import std.concurrency;
import std.getopt;
import std.exception;
import std.stdio;
import std.range;

void main(string[] args) {
    int nums = 1_000_000;
    getopt(args, "nums|n", &nums);
    int[] numbers = iota(0, nums).array();
    stdout.writeln("one thread...");
    stdout.writeln("sum = ", sum(numbers));
    stdout.writeln("two threads...");
    stdout.writeln("sum = ", concurrentSum(numbers));
}

int concurrentSum(int[] mutableArray) {
    // D, I promise I won't modify mutableArray.
    auto immutableArray = mutableArray.assumeUnique();
    
    // midpoint of array
    auto mid = immutableArray.length / 2;
    
    // spawn new threads
    auto tid1 = spawn(&getsum, thisTid, immutableArray[0 .. mid]);
    auto tid2 = spawn(&getsum, thisTid, immutableArray[mid .. $]);
    
    // get result
    int result;
    foreach(i; 0 .. 2) {
        receive((ResultMsg res) { result += res; });
    }
    return result;
}

void getsum(Tid tid, immutable(int)[] array) {
    tid.send(ResultMsg(sum(array)));
}

struct ResultMsg {
    this(int res) { this.res = res; }
    int res;
    alias res this;
}

int sum(const(int)[] array) {
    return reduce!"a + b"(0, array);
}

Application output:

one thread...
sum = 1783293664
two threads...

Application error:

core.thread.ThreadException@src/core/thread.d(724): Error creating thread
----------------
----------------

Paste info

Author: Guest

Views: 181

Private: no

Expires: Never

Uploaded: 28.06.12 1:39

Votes: 0

Compilation

Compiler: DMD 2.062

Pointer size: m64