///////////////////////////////////////////////////////////////////////////////
//
//  Microsoft Research Singularity
//
//  Copyright (c) Microsoft Corporation.  All rights reserved.
//
//  Note:   Allocate strings and encourage GCs
//

using System;
using System.Collections;
using System.Threading;

using Microsoft.Singularity.UnitTest;

namespace Microsoft.Singularity.Applications
{
    public class ForkTest
    {
        static readonly string []! ProcessArgs = new string[] { "testpe" };
        static readonly TimeSpan ProcessTimeout = TimeSpan.FromSeconds(10);
        const int IterationsPerThread = 64;

        static object! monitor = new object();
        static AutoResetEvent! exitEvent = new AutoResetEvent(false);
        static int threadCount;

        private static void ThreadMain()
        {
            lock (ForkTest.monitor) {
                ForkTest.threadCount++;
            }

            for (int i = 0; i < IterationsPerThread; i++) {
                Process process = new Process(ForkTest.ProcessArgs);
                process.Start();
                Assert.True(process.Join(ProcessTimeout),
                            "Failed to join process.");
            }

            lock (ForkTest.monitor) {
                ForkTest.threadCount--;
                if (ForkTest.threadCount == 0) {
                    ForkTest.exitEvent.Set();
                }
            }
        }

        public static void Run()
        {
            ForkTest.monitor     = new object();
            ForkTest.exitEvent   = new AutoResetEvent(false);
            ForkTest.threadCount = 0;

            for (int i = 0; i < Settings.MaxThreads; i++) {
                Thread t = new Thread(new ThreadStart(ThreadMain));
                t.Start();
            }
            ForkTest.exitEvent.WaitOne();
        }
    }
}