mcs/class/System/System.IO.Ports/WinSerialStream.cs

   1 //
   2 // System.IO.Ports.WinSerialStream.cs
   3 //
   4 // Authors:
   5 //      Carlos Alberto Cortez (calberto.cortez@gmail.com)
   6 //
   7 // (c) Copyright 2006 Novell, Inc. (http://www.novell.com)
   8 //
   9
  10 using System;
  11 using System.Text;
  12 using System.IO;
  13 using System.Runtime.InteropServices;
  14 using System.Threading;
  15 using System.ComponentModel;
  16
  17 namespace System.IO.Ports
  18 {
  19         class WinSerialStream : Stream, ISerialStream, IDisposable
  20         {
  21                 // Windows API Constants
  22                 const uint GenericRead = 0x80000000;
  23                 const uint GenericWrite = 0x40000000;
  24                 const uint OpenExisting = 3;
  25                 const uint FileFlagOverlapped = 0x40000000;
  26                 const uint PurgeRxClear = 0x0008;
  27                 const uint PurgeTxClear = 0x0004;
  28                 const uint WinInfiniteTimeout = 0xFFFFFFFF;
  29                 const uint FileIOPending = 997;
  30
  31                 // Signal constants
  32                 const uint SetRts = 3;
  33                 const uint ClearRts = 4;
  34                 const uint SetDtr = 5;
  35                 const uint ClearDtr = 6;
  36                 const uint SetBreak = 8;
  37                 const uint ClearBreak = 9;
  38                 const uint CtsOn = 0x0010;
  39                 const uint DsrOn = 0x0020;
  40                 const uint RsldOn = 0x0080;
  41
  42                 // Event constants
  43                 const uint EvRxChar = 0x0001;
  44                 const uint EvCts = 0x0008;
  45                 const uint EvDsr = 0x0010;
  46                 const uint EvRlsd = 0x0020;
  47                 const uint EvBreak = 0x0040;
  48                 const uint EvErr = 0x0080;
  49                 const uint EvRing = 0x0100;
  50
  51                 int handle;
  52                 int read_timeout;
  53                 int write_timeout;
  54                 bool disposed;
  55                 IntPtr write_overlapped;
  56                 IntPtr read_overlapped;
  57                 ManualResetEvent read_event;
  58                 ManualResetEvent write_event;
  59                 Timeouts timeouts;
  60
  61                 [DllImport("kernel32", SetLastError = true)]
  62                 static extern int CreateFile(string port_name, uint desired_access,
  63                                 uint share_mode, uint security_attrs, uint creation, uint flags,
  64                                 uint template);
  65
  66                 [DllImport("kernel32", SetLastError = true)]
  67                 static extern bool SetupComm(int handle, int read_buffer_size, int write_buffer_size);
  68
  69                 [DllImport("kernel32", SetLastError = true)]
  70                 static extern bool PurgeComm(int handle, uint flags);
  71
  72                 [DllImport("kernel32", SetLastError = true)]
  73                 static extern bool SetCommTimeouts(int handle, Timeouts timeouts);
  74
  75                 public WinSerialStream (string port_name, int baud_rate, int data_bits, Parity parity, StopBits sb,
  76                                 bool dtr_enable, bool rts_enable, Handshake hs, int read_timeout, int write_timeout,
  77                                 int read_buffer_size, int write_buffer_size)
  78                 {
  79                         handle = CreateFile (port_name != null && !port_name.StartsWith(@"\\.\")
  80                                         ? @"\\.\" + port_name : port_name,
  81                                         GenericRead | GenericWrite, 0, 0, OpenExisting,
  82                                         FileFlagOverlapped, 0);
  83
  84                         if (handle == -1)
  85                                 ReportIOError (port_name);
  86
  87                         // Set port low level attributes
  88                         SetAttributes (baud_rate, parity, data_bits, sb, hs);
  89
  90                         // Clean buffers and set sizes
  91                         if (!PurgeComm (handle, PurgeRxClear | PurgeTxClear) ||
  92                                         !SetupComm (handle, read_buffer_size, write_buffer_size))
  93                                 ReportIOError (null);
  94
  95                         // Set timeouts
  96                         this.read_timeout = read_timeout;
  97                         this.write_timeout = write_timeout;
  98                         timeouts = new Timeouts (read_timeout, write_timeout);
  99                         if (!SetCommTimeouts(handle, timeouts))
 100                                 ReportIOError (null);
 101
 102                         /// Set DTR and RTS
 103                         SetSignal(SerialSignal.Dtr, dtr_enable);
 104
 105                         if (hs != Handshake.RequestToSend &&
 106                                         hs != Handshake.RequestToSendXOnXOff)
 107                                 SetSignal(SerialSignal.Rts, rts_enable);
 108
 109                         // Init overlapped structures
 110                         NativeOverlapped wo = new NativeOverlapped ();
 111                         write_event = new ManualResetEvent (false);
 112 #pragma warning disable 618
 113                         wo.EventHandle = write_event.Handle;
 114                         write_overlapped = Marshal.AllocHGlobal (Marshal.SizeOf (typeof (NativeOverlapped)));
 115                         Marshal.StructureToPtr (wo, write_overlapped, true);
 116
 117                         NativeOverlapped ro = new NativeOverlapped ();
 118                         read_event = new ManualResetEvent (false);
 119                         ro.EventHandle = read_event.Handle;
 120                         read_overlapped = Marshal.AllocHGlobal (Marshal.SizeOf (typeof (NativeOverlapped)));
 121                         Marshal.StructureToPtr (ro, read_overlapped, true);
 122 #pragma warning restore 618
 123                 }
 124
 125                 public override bool CanRead {
 126                         get {
 127                                 return true;
 128                         }
 129                 }
 130
 131                 public override bool CanSeek {
 132                         get {
 133                                 return false;
 134                         }
 135                 }
 136
 137                 public override bool CanTimeout {
 138                         get {
 139                                 return true;
 140                         }
 141                 }
 142
 143                 public override bool CanWrite {
 144                         get {
 145                                 return true;
 146                         }
 147                 }
 148
 149                 public override int ReadTimeout {
 150                         get {
 151                                 return read_timeout;
 152                         }
 153                         set {
 154                                 if (value < 0 && value != SerialPort.InfiniteTimeout)
 155                                         throw new ArgumentOutOfRangeException ("value");
 156
 157                                 timeouts.SetValues (value, write_timeout);
 158                                 if (!SetCommTimeouts (handle, timeouts))
 159                                         ReportIOError (null);
 160
 161                                 read_timeout = value;
 162                         }
 163                 }
 164
 165                 public override int WriteTimeout {
 166                         get {
 167                                 return write_timeout;
 168                         }
 169                         set
 170                         {
 171                                 if (value < 0 && value != SerialPort.InfiniteTimeout)
 172                                         throw new ArgumentOutOfRangeException ("value");
 173
 174                                 timeouts.SetValues (read_timeout, value);
 175                                 if (!SetCommTimeouts (handle, timeouts))
 176                                         ReportIOError (null);
 177
 178                                 write_timeout = value;
 179                         }
 180                 }
 181
 182                 public override long Length {
 183                         get {
 184                                 throw new NotSupportedException ();
 185                         }
 186                 }
 187
 188                 public override long Position {
 189                         get {
 190                                 throw new NotSupportedException ();
 191                         }
 192                         set {
 193                                 throw new NotSupportedException ();
 194                         }
 195                 }
 196
 197                 [DllImport("kernel32", SetLastError = true)]
 198                 static extern bool CloseHandle (int handle);
 199
 200                 protected override void Dispose (bool disposing)
 201                 {
 202                         if (disposed)
 203                                 return;
 204
 205                         disposed = true;
 206                         CloseHandle (handle);
 207                         Marshal.FreeHGlobal (write_overlapped);
 208                         Marshal.FreeHGlobal (read_overlapped);
 209                 }
 210
 211                 void IDisposable.Dispose ()
 212                 {
 213                         Dispose (true);
 214                         GC.SuppressFinalize (this);
 215                 }
 216
 217                 public override void Close ()
 218                 {
 219                         ((IDisposable)this).Dispose ();
 220                 }
 221
 222                 ~WinSerialStream ()
 223                 {
 224                         Dispose (false);
 225                 }
 226
 227                 public override void Flush ()
 228                 {
 229                         CheckDisposed ();
 230                         // No dothing by now
 231                 }
 232
 233                 public override long Seek (long offset, SeekOrigin origin)
 234                 {
 235                         throw new NotSupportedException();
 236                 }
 237
 238                 public override void SetLength (long value)
 239                 {
 240                         throw new NotSupportedException();
 241                 }
 242
 243                 [DllImport("kernel32", SetLastError = true)]
 244                         static extern unsafe bool ReadFile (int handle, byte* buffer, int bytes_to_read,
 245                                         out int bytes_read, IntPtr overlapped);
 246
 247                 [DllImport("kernel32", SetLastError = true)]
 248                         static extern unsafe bool GetOverlappedResult (int handle, IntPtr overlapped,
 249                                         ref int bytes_transfered, bool wait);
 250
 251                 public override int Read ([In, Out] byte [] buffer, int offset, int count)
 252                 {
 253                         CheckDisposed ();
 254                         if (buffer == null)
 255                                 throw new ArgumentNullException ("buffer");
 256                         if (offset < 0 || count < 0)
 257                                 throw new ArgumentOutOfRangeException ("offset or count less than zero.");
 258
 259                         if (buffer.Length - offset < count )
 260                                 throw new ArgumentException ("offset+count",
 261                                                               "The size of the buffer is less than offset + count.");
 262
 263                         int bytes_read;
 264
 265                         unsafe {
 266                                 fixed (byte* ptr = buffer) {
 267                                         if (ReadFile (handle, ptr + offset, count, out bytes_read, read_overlapped))
 268                                                 return bytes_read;
 269
 270                                         // Test for overlapped behavior
 271                                         if (Marshal.GetLastWin32Error () != FileIOPending)
 272                                                 ReportIOError (null);
 273
 274                                         if (!GetOverlappedResult (handle, read_overlapped, ref bytes_read, true))
 275                                                 ReportIOError (null);
 276
 277                                 }
 278                         }
 279
 280                         if (bytes_read == 0)
 281                                 throw new TimeoutException (); // We didn't get any byte
 282
 283                         return bytes_read;
 284                 }
 285
 286                 [DllImport("kernel32", SetLastError = true)]
 287                 static extern unsafe bool WriteFile (int handle, byte* buffer, int bytes_to_write,
 288                                 out int bytes_written, IntPtr overlapped);
 289
 290                 public override void Write (byte [] buffer, int offset, int count)
 291                 {
 292                         CheckDisposed ();
 293                         if (buffer == null)
 294                                 throw new ArgumentNullException ("buffer");
 295
 296                         if (offset < 0 || count < 0)
 297                                 throw new ArgumentOutOfRangeException ();
 298
 299                         if (buffer.Length - offset < count)
 300                                 throw new ArgumentException ("offset+count",
 301                                                              "The size of the buffer is less than offset + count.");
 302
 303                         int bytes_written = 0;
 304
 305                         unsafe {
 306                                 fixed (byte* ptr = buffer) {
 307                                         if (WriteFile (handle, ptr + offset, count, out bytes_written, write_overlapped))
 308                                                 return;
 309                                         if (Marshal.GetLastWin32Error() != FileIOPending)
 310                                                 ReportIOError (null);
 311
 312                                         if (!GetOverlappedResult(handle, write_overlapped, ref bytes_written, true))
 313                                                 ReportIOError (null);
 314                                 }
 315                         }
 316
 317                         // If the operation timed out, then
 318                         // we transfered less bytes than the requested ones
 319                         if (bytes_written < count)
 320                                 throw new TimeoutException ();
 321                 }
 322
 323                 [DllImport("kernel32", SetLastError = true)]
 324                 static extern bool GetCommState (int handle, [Out] DCB dcb);
 325
 326                 [DllImport ("kernel32", SetLastError=true)]
 327                 static extern bool SetCommState (int handle, DCB dcb);
 328
 329                 public void SetAttributes (int baud_rate, Parity parity, int data_bits, StopBits bits, Handshake hs)
 330                 {
 331                         DCB dcb = new DCB ();
 332                         if (!GetCommState (handle, dcb))
 333                                 ReportIOError (null);
 334
 335                         dcb.SetValues (baud_rate, parity, data_bits, bits, hs);
 336                         if (!SetCommState (handle, dcb))
 337                                 ReportIOError (null);
 338                 }
 339
 340                 void ReportIOError(string optional_arg)
 341                 {
 342                         int error = Marshal.GetLastWin32Error ();
 343                         string message;
 344                         switch (error) {
 345                                 case 2:
 346                                 case 3:
 347                                         message = "The port `" + optional_arg + "' does not exist.";
 348                                         break;
 349                                 case 87:
 350                                         message = "Parameter is incorrect.";
 351                                         break;
 352                                 default:
 353                                         // As fallback, we show the win32 error
 354                                         message = new Win32Exception ().Message;
 355                                         break;
 356                         }
 357
 358                         throw new IOException (message);
 359                 }
 360
 361                 void CheckDisposed ()
 362                 {
 363                         if (disposed)
 364                                 throw new ObjectDisposedException (GetType ().FullName);
 365                 }
 366
 367                 // ISerialStream members
 368                 public void DiscardInBuffer ()
 369                 {
 370                         if (!PurgeComm (handle, PurgeRxClear))
 371                                 ReportIOError (null);
 372                 }
 373
 374                 public void DiscardOutBuffer ()
 375                 {
 376                         if (!PurgeComm (handle, PurgeTxClear))
 377                                 ReportIOError (null);
 378                 }
 379
 380                 [DllImport ("kernel32", SetLastError=true)]
 381                 static extern bool ClearCommError (int handle, out uint errors, out CommStat stat);
 382
 383                 public int BytesToRead {
 384                         get {
 385                                 uint errors;
 386                                 CommStat stat;
 387                                 if (!ClearCommError (handle, out errors, out stat))
 388                                         ReportIOError (null);
 389
 390                                 return (int)stat.BytesIn;
 391                         }
 392                 }
 393
 394                 public int BytesToWrite {
 395                         get {
 396                                 uint errors;
 397                                 CommStat stat;
 398                                 if (!ClearCommError (handle, out errors, out stat))
 399                                         ReportIOError (null);
 400
 401                                 return (int)stat.BytesOut;
 402                         }
 403                 }
 404
 405                 [DllImport ("kernel32", SetLastError=true)]
 406                 static extern bool GetCommModemStatus (int handle, out uint flags);
 407
 408                 public SerialSignal GetSignals ()
 409                 {
 410                         uint flags;
 411                         if (!GetCommModemStatus (handle, out flags))
 412                                 ReportIOError (null);
 413
 414                         SerialSignal signals = SerialSignal.None;
 415                         if ((flags & RsldOn) != 0)
 416                                 signals |= SerialSignal.Cd;
 417                         if ((flags & CtsOn) != 0)
 418                                 signals |= SerialSignal.Cts;
 419                         if ((flags & DsrOn) != 0)
 420                                 signals |= SerialSignal.Dsr;
 421
 422                         return signals;
 423                 }
 424
 425                 [DllImport ("kernel32", SetLastError=true)]
 426                 static extern bool EscapeCommFunction (int handle, uint flags);
 427
 428                 public void SetSignal (SerialSignal signal, bool value)
 429                 {
 430                         if (signal != SerialSignal.Rts && signal != SerialSignal.Dtr)
 431                                 throw new Exception ("Wrong internal value");
 432
 433                         uint flag;
 434                         if (signal == SerialSignal.Rts)
 435                                 if (value)
 436                                         flag = SetRts;
 437                                 else
 438                                         flag = ClearRts;
 439                         else
 440                                 if (value)
 441                                         flag = SetDtr;
 442                                 else
 443                                         flag = ClearDtr;
 444
 445                         if (!EscapeCommFunction (handle, flag))
 446                                 ReportIOError (null);
 447                 }
 448
 449                 public void SetBreakState (bool value)
 450                 {
 451                         if (!EscapeCommFunction (handle, value ? SetBreak : ClearBreak))
 452                                 ReportIOError (null);
 453                 }
 454
 455         }
 456
 457         [StructLayout (LayoutKind.Sequential)]
 458         class DCB
 459         {
 460                 public int dcb_length;
 461                 public int baud_rate;
 462                 public int flags;
 463                 public short w_reserved;
 464                 public short xon_lim;
 465                 public short xoff_lim;
 466                 public byte byte_size;
 467                 public byte parity;
 468                 public byte stop_bits;
 469                 public byte xon_char;
 470                 public byte xoff_char;
 471                 public byte error_char;
 472                 public byte eof_char;
 473                 public byte evt_char;
 474                 public short w_reserved1;
 475
 476                 // flags:
 477                 //const int fBinary = 0x0001;
 478                 //const int fParity = 0x0002;
 479                 const int fOutxCtsFlow = 0x0004;
 480                 //const int fOutxDsrFlow1 = 0x0008;
 481                 //const int fOutxDsrFlow2 = 0x0010;
 482                 //const int fDtrControl = 0x00020;
 483                 //const int fDsrSensitivity = 0x0040;
 484                 //const int fTXContinueOnXoff = 0x0080;
 485                 const int fOutX = 0x0100;
 486                 const int fInX = 0x0200;
 487                 //const int fErrorChar = 0x0400;
 488                 //const int fNull = 0x0800;
 489                 //const int fRtsControl1 = 0x1000;
 490                 const int fRtsControl2 = 0x2000;
 491                 //const int fAbortOnError = 0x4000;
 492
 493                 public void SetValues (int baud_rate, Parity parity, int byte_size, StopBits sb, Handshake hs)
 494                 {
 495                         switch (sb) {
 496                                 case StopBits.One:
 497                                         stop_bits = 0;
 498                                         break;
 499                                 case StopBits.OnePointFive:
 500                                         stop_bits = 1;
 501                                         break;
 502                                 case StopBits.Two:
 503                                         stop_bits = 2;
 504                                         break;
 505                                 default: // Shouldn't happen
 506                                         break;
 507                         }
 508
 509                         this.baud_rate = baud_rate;
 510                         this.parity = (byte)parity;
 511                         this.byte_size = (byte)byte_size;
 512
 513                         // Clear Handshake flags
 514                         flags &= ~(fOutxCtsFlow | fOutX | fInX | fRtsControl2);
 515
 516                         // Set Handshake flags
 517                         switch (hs)
 518                         {
 519                                 case Handshake.None:
 520                                         break;
 521                                 case Handshake.XOnXOff:
 522                                         flags |= fOutX | fInX;
 523                                         break;
 524                                 case Handshake.RequestToSend:
 525                                         flags |= fOutxCtsFlow | fRtsControl2;
 526                                         break;
 527                                 case Handshake.RequestToSendXOnXOff:
 528                                         flags |= fOutxCtsFlow | fOutX | fInX | fRtsControl2;
 529                                         break;
 530                                 default: // Shouldn't happen
 531                                         break;
 532                         }
 533                 }
 534         }
 535
 536         [StructLayout (LayoutKind.Sequential)]
 537         class Timeouts
 538         {
 539                 public uint ReadIntervalTimeout;
 540                 public uint ReadTotalTimeoutMultiplier;
 541                 public uint ReadTotalTimeoutConstant;
 542                 public uint WriteTotalTimeoutMultiplier;
 543                 public uint WriteTotalTimeoutConstant;
 544
 545                 public const uint MaxDWord = 0xFFFFFFFF;
 546
 547                 public Timeouts (int read_timeout, int write_timeout)
 548                 {
 549                         SetValues (read_timeout, write_timeout);
 550                 }
 551
 552                 public void SetValues (int read_timeout, int write_timeout)
 553                 {
 554                         // FIXME: The windows api docs are not very clear about read timeouts,
 555                         // and we have to simulate infinite with a big value (uint.MaxValue - 1)
 556                         ReadIntervalTimeout = MaxDWord;
 557                         ReadTotalTimeoutMultiplier = MaxDWord;
 558                         ReadTotalTimeoutConstant = (read_timeout == -1 ? MaxDWord - 1 : (uint) read_timeout);
 559
 560                         WriteTotalTimeoutMultiplier = 0;
 561                         WriteTotalTimeoutConstant = (write_timeout == -1 ? MaxDWord : (uint) write_timeout);
 562                 }
 563
 564         }
 565
 566         [StructLayout (LayoutKind.Sequential)]
 567         struct CommStat
 568         {
 569                 public uint flags;
 570                 public uint BytesIn;
 571                 public uint BytesOut;
 572         }
 573 }
 574
 575