예제 #1
0
        /// <summary>
        /// Connects to a server named pipe.
        /// </summary>
        /// <param name="pipeName">The pipe name.</param>
        /// <param name="serverName">The server name.</param>
        /// <returns>The pipe handle, which also contains the pipe state.</returns>
        /// <remarks>This method is used by clients to establish a pipe connection with a server pipe.</remarks>
        #endregion
        public static PipeHandle ConnectToPipe(string pipeName, string serverName)
        {
            PipeHandle handle = new PipeHandle();
            // Build the name of the pipe.
            string name = @"\\" + serverName + @"\pipe\" + pipeName;

            for (int i = 1; i <= ATTEMPTS; i++)
            {
                handle.State = InterProcessConnectionState.ConnectingToServer;
                // Try to connect to the server
                handle.Handle = NamedPipeNative.CreateFile(name, NamedPipeNative.GENERIC_READ | NamedPipeNative.GENERIC_WRITE, 0, null, NamedPipeNative.OPEN_EXISTING, 0, 0);
                if (handle.Handle.ToInt32() != NamedPipeNative.INVALID_HANDLE_VALUE)
                {
                    // The client managed to connect to the server pipe
                    handle.State = InterProcessConnectionState.ConnectedToServer;
                    // Set the read mode of the pipe channel
                    uint mode = NamedPipeNative.PIPE_READMODE_MESSAGE;
                    if (NamedPipeNative.SetNamedPipeHandleState(handle.Handle, ref mode, IntPtr.Zero, IntPtr.Zero))
                    {
                        break;
                    }
                    if (i >= ATTEMPTS)
                    {
                        handle.State = InterProcessConnectionState.Error;
                        throw new NamedPipeIOException("Error setting read mode on pipe " + name + " . Internal error: " + NamedPipeNative.GetLastError().ToString(), NamedPipeNative.GetLastError());
                    }
                }
                if (i >= ATTEMPTS)
                {
                    if (NamedPipeNative.GetLastError() != NamedPipeNative.ERROR_PIPE_BUSY)
                    {
                        handle.State = InterProcessConnectionState.Error;
                        // After a certain number of unsuccessful attempt raise an exception
                        throw new NamedPipeIOException("Error connecting to pipe " + name + " . Internal error: " + NamedPipeNative.GetLastError().ToString(), NamedPipeNative.GetLastError());
                    }
                    else
                    {
                        handle.State = InterProcessConnectionState.Error;
                        throw new NamedPipeIOException("Pipe " + name + " is too busy. Internal error: " + NamedPipeNative.GetLastError().ToString(), NamedPipeNative.GetLastError());
                    }
                }
                else
                {
                    // The pipe is busy so lets wait for some time and try again
                    if (NamedPipeNative.GetLastError() == NamedPipeNative.ERROR_PIPE_BUSY)
                    {
                        NamedPipeNative.WaitNamedPipe(name, WAIT_TIME);
                    }
                }
            }

            return(handle);
        }
예제 #2
0
        /// <summary>
        /// Tries to connect to a named pipe.
        /// </summary>
        /// <param name="pipeName">The name of the pipe.</param>
        /// <param name="serverName">The name of the server.</param>
        /// <param name="handle">The resulting pipe handle.</param>
        /// <returns>Return true if the attempt succeeds.</returns>
        /// <remarks>This method is used mainly when stopping the pipe server. It unblocks the existing pipes, which wait for client connection.</remarks>
        #endregion
        public static bool TryConnectToPipe(string pipeName, string serverName, out PipeHandle handle)
        {
            handle = new PipeHandle();
            // Build the pipe name string
            string name = @"\\" + serverName + @"\pipe\" + pipeName;

            handle.State = InterProcessConnectionState.ConnectingToServer;
            // Try to connect to a server pipe
            handle.Handle = NamedPipeNative.CreateFile(name, NamedPipeNative.GENERIC_READ | NamedPipeNative.GENERIC_WRITE, 0, null, NamedPipeNative.OPEN_EXISTING, 0, 0);
            if (handle.Handle.ToInt32() != NamedPipeNative.INVALID_HANDLE_VALUE)
            {
                handle.State = InterProcessConnectionState.ConnectedToServer;
                return(true);
            }
            else
            {
                handle.State = InterProcessConnectionState.Error;
                return(false);
            }
        }