singrdk/base/Applications/CHello/CHello.sg

////////////////////////////////////////////////////////////////////////////////
//
//  Microsoft Research Singularity
//
//  Copyright (c) Microsoft Corporation.  All rights reserved.
//
//  Note:   Simple Singularity test program.
//
using System;                               // Console, String etc
using Microsoft.Singularity.Applications;   // ApplicationResourceTransform
using Microsoft.Singularity.Channels;       // TRef
using Microsoft.Singularity.Configuration;  // ConsoleCategory, InputEndpoint, OutputEndpoint
using Microsoft.Singularity.Directory;      // DirectoryServiceContract, ErrorCode, DirectoryService, SdsUtils
using Microsoft.Singularity.Io;             // UnicodePipeContract, DiskDeviceContract
using Microsoft.SingSharp.Reflection;       // Transform namespace

// change "public static int Main(String[] args)" to "internal static int Main(DefaultConfig! config)"
[assembly: Transform(typeof(ApplicationResourceTransform))]
namespace Microsoft.Singularity.Applications
{
    [ConsoleCategory(HelpMessage="Classic Hello World app", DefaultAction=true)]
    internal class DefaultConfig {
        [InputEndpoint("data")]
        public readonly TRef<UnicodePipeContract.Exp:READY> Stdin;

        [OutputEndpoint("data")]
        public readonly TRef<UnicodePipeContract.Imp:READY> Stdout;

        reflective internal DefaultConfig();

        internal int AppMain() {
            return CHello.Main(this);
        }
    }

    public class CHello
    {
        public static DiskDeviceContract.Imp:Ready OpenDevice(String! devname)
        {
            DiskDeviceContract.Exp! exp;
            DiskDeviceContract.Imp! imp;
            DiskDeviceContract.NewChannel(out imp, out exp);
            DirectoryServiceContract.Imp ns;

            // get NS endpoint
            ns = DirectoryService.NewClientEndpoint();
            bool success = false;
            ErrorCode error; 
            success = SdsUtils.Bind(devname, ns, exp, out error);
            if (!success) {
                Console.WriteLine("Bind of {0} failed\n", devname);
                delete imp;
                delete ns;
                return null;
            }
            switch receive {
                case imp.Success():
                    break;
                case imp.ContractNotSupported():
                    Console.WriteLine("{0} does not support DiskDevice", devname);
                    delete imp;
                    delete ns;
                    return null;
                case imp.ChannelClosed():
                    Console.WriteLine("DiskDevice channel to {0} closed unexpectedly", devname);
                    delete imp;
                    delete ns;
                    return null;
            }

            delete ns;
            return imp;
        }

        internal static int Main(DefaultConfig! config)
        {
            Console.WriteLine("Hello World!");

            DiskDeviceContract.Imp device = OpenDevice("/dev/disk0");
            if (device == null) {
                Console.WriteLine("Couldn't open disk0");
                return 1;
            }
            delete device;
            Console.WriteLine("Opened disk0");
            return 0;
        }
    }
}