/// <summary>
/// Creates <see cref="System.Threading.Semaphore"/> to start remoting.
/// </summary>
/// <param name="name">Name</param>
/// <param name="args">Arguments to another instance</param>
/// <returns>
/// <para>success: True if no other instance exists and this instance successfully creates</para>
/// <para>response: Response from another instance if that instance exists and returns an response</para>
/// </returns>
public (bool success, object response) Create(string name, string[] args)
{
if (string.IsNullOrWhiteSpace(name))
{
throw new ArgumentNullException(nameof(name));
}
// Determine Semaphore name and IPC port name.
var semaphoreName = $"semaphore-{name}";
var ipcPortName = $"port-{name}";
const string ipcUri = "space";
_semaphore = new Semaphore(1, 1, semaphoreName, out bool createdNew);
if (createdNew)
{
try
{
// Instantiate a server channel and register it.
_server = new IpcServerChannel(ipcPortName);
ChannelServices.RegisterChannel(_server, true);
// Instantiate a remoting object and publish it.
_space = new RemotingSpace();
RemotingServices.Marshal(_space, ipcUri, typeof(RemotingSpace));
}
catch (RemotingException ex)
{
Debug.WriteLine("Failed to start remoting as server." + Environment.NewLine
+ ex);
}
return(success : true, null);
}
else
{
object response = null;
try
{
// Instantiate a client channel and register it.
var client = new IpcClientChannel();
ChannelServices.RegisterChannel(client, true);
// Set a proxy for a remoting object instantiated by another instance.
var ipcPath = $"ipc://{ipcPortName}/{ipcUri}";
_space = Activator.GetObject(typeof(RemotingSpace), ipcPath) as RemotingSpace;
// Request that instance to take an action. If it is older version, RemotingException
// will be thrown because the remoting object has no such method.
response = _space?.Request(args);
}
catch (RemotingException ex)
{
Debug.WriteLine("Failed to start remoting as client." + Environment.NewLine
+ ex);
}
return(success : false, response);
}
}
/// <summary>
/// Creates semaphore to start remoting.
/// </summary>
/// <returns>True if no other instance there and this instance instantiated remoting server</returns>
public bool Create(string title)
{
if (string.IsNullOrWhiteSpace(title))
{
throw new ArgumentNullException(nameof(title));
}
// Determine Semaphore name and IPC port name using assembly title.
var semaphoreName = $"semaphore-{title}";
var ipcPortName = $"port-{title}";
const string ipcUri = "space";
_semaphore = new Semaphore(1, 1, semaphoreName, out bool createdNew);
if (createdNew)
{
try
{
// Instantiate a server channel and register it.
_server = new IpcServerChannel(ipcPortName);
ChannelServices.RegisterChannel(_server, true);
// Instantiate a remoting object and publish it.
_space = new RemotingSpace();
RemotingServices.Marshal(_space, ipcUri, typeof(RemotingSpace));
}
catch (RemotingException ex)
{
Debug.WriteLine("Failed to start remoting." + Environment.NewLine
+ ex);
}
return(true);
}
else
{
try
{
// Instantiate a client channel and register it.
var client = new IpcClientChannel();
ChannelServices.RegisterChannel(client, true);
// Set a proxy for remote object.
var ipcPath = $"ipc://{ipcPortName}/{ipcUri}";
_space = Activator.GetObject(typeof(RemotingSpace), ipcPath) as RemotingSpace;
// Raise event.
_space?.RaiseShowRequested();
}
catch (RemotingException ex)
{
Debug.WriteLine("Failed to start remoting." + Environment.NewLine
+ ex);
}
return(false);
}
}
