如何在Ruby on Rails Web服务器上进行编译和编码，从而限制CPU和内存的使用？

Question

I have a cpp code being submitted by user. I also have input and output files in my db. How do compile and run this cpp code on the input and output file I have.

Additionally how can I restrict running time and memory consumption of the above running of code. Also how do I measure how much memory is being and how much time it took to execute the above code.

Edit I got this below hack working. Now the only problem how do I limit the memory usage of running program. I will appreciate if it would be OS independent. But if its not possible solution for both Windows and Linux are welcome.

require 'timeout'

    runDir = 'run\\'

    def code_file( sid )
        return "#{sid}.cpp"
    end

    def executable_file( sid )
        return "#{sid}.exe"
    end

    def input_file( sid )
        return "#{sid}.in"
    end

    def output_file( sid )
        return "#{sid}.out"
    end

    def get_complie_command_line( sid , runDir)
        return "g++ -w -O2 #{code_file(sid)} -o #{runDir}#{executable_file(sid)}"
    end

    def get_run_command_line( sid , runDir )
        return "#{runDir}#{executable_file(sid)} < #{sid}.in"
    end

    def run_submission( sid , runDir )
        begin
        timeout(5) {
            run_cmd_line = get_run_command_line( 1 , runDir)
            puts run_cmd_line
            runOutput = %x[#{run_cmd_line}]
            puts runOutput
        }
        puts "Timeout didn't occur"
        rescue Timeout::Error    
            puts "Timed out!"
        end
    end

    def compile( sid , runDir )
        #make the directory 
        %x[mkdir #{runDir}]

        #get compile command line and produce the exe
        cmd_line = get_complie_command_line( 1 , runDir)
        puts cmd_line
        compile_error = %x[#{cmd_line}].to_s.strip

        #run the code
        if compile_error.length != 0 
            puts "Compile Errors"
        else
            run_submission( 1 , runDir )
        end
    end



    compile( 1 , runDir)

Answer 1

You can create some run script with your ruby code, say run.sh if you're using *nix-like operating system. The context of this script will be smth like this:

#!/bin/bash
/path/to/timeout /path/to/your/compiled/cpp/program < /your/stdin > /your/stdout

Where the timeout program is this perl script https://github.com/pshved/timeout It will kill your program if it breaches time or memory limit. From ruby you will just execute run.sh script ( run.sh ) or smth like that. For Windows you can use same aproach