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 #if NET_2_0
  18
  19 namespace System.IO.Ports
  20 {
  21         class WinSerialStream : Stream, ISerialStream, IDisposable
  22         {
  23                 // Windows API Constants
  24                 const uint GenericRead = 0x80000000;
  25                 const uint GenericWrite = 0x40000000;
  26                 const uint OpenExisting = 3;
  27                 const uint FileFlagOverlapped = 0x40000000;
  28                 const uint PurgeRxClear = 0x0004;
  29                 const uint PurgeTxClear = 0x0008;
  30                 const uint WinInfiniteTimeout = 0xFFFFFFFF;
  31                 const uint FileIOPending = 997;
  32
  33                 // Signal constants
  34                 const uint SetRts = 3;
  35                 const uint ClearRts = 4;
  36                 const uint SetDtr = 5;
  37                 const uint ClearDtr = 6;
  38                 const uint SetBreak = 8;
  39                 const uint ClearBreak = 9;
  40                 const uint CtsOn = 0x0010;
  41                 const uint DsrOn = 0x0020;
  42                 const uint RsldOn = 0x0080;
  43
  44                 // Event constants
  45                 const uint EvRxChar = 0x0001;
  46                 const uint EvCts = 0x0008;
  47                 const uint EvDsr = 0x0010;
  48                 const uint EvRlsd = 0x0020;
  49                 const uint EvBreak = 0x0040;
  50                 const uint EvErr = 0x0080;
  51                 const uint EvRing = 0x0100;
  52
  53                 int handle;
  54                 int read_timeout;
  55                 int write_timeout;
  56                 bool disposed;
  57                 IntPtr write_overlapped;
  58                 IntPtr read_overlapped;
  59                 ManualResetEvent read_event;
  60                 ManualResetEvent write_event;
  61                 Timeouts timeouts;
  62
  63                 [DllImport("kernel32", SetLastError = true)]
  64                 static extern int CreateFile(string port_name, uint desired_access,
  65                                 uint share_mode, uint security_attrs, uint creation, uint flags,
  66                                 uint template);
  67
  68                 [DllImport("kernel32", SetLastError = true)]
  69                 static extern bool SetupComm(int handle, int read_buffer_size, int write_buffer_size);
  70
  71                 [DllImport("kernel32", SetLastError = true)]
  72                 static extern bool PurgeComm(int handle, uint flags);
  73
  74                 [DllImport("kernel32", SetLastError = true)]
  75                 static extern bool SetCommTimeouts(int handle, Timeouts timeouts);
  76
  77                 public WinSerialStream (string port_name, int baud_rate, int data_bits, Parity parity, StopBits sb,
  78                                 bool dtr_enable, bool rts_enable, Handshake hs, int read_timeout, int write_timeout,
  79                                 int read_buffer_size, int write_buffer_size)
  80                 {
  81                         handle = CreateFile (port_name, 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 #if NET_2_0
 113                         wo.EventHandle = write_event.Handle;
 114 #else
 115                         wo.EventHandle = (int) write_event.Handle;
 116 #endif
 117                         write_overlapped = Marshal.AllocHGlobal (Marshal.SizeOf (typeof (NativeOverlapped)));
 118                         Marshal.StructureToPtr (wo, write_overlapped, true);
 119
 120                         NativeOverlapped ro = new NativeOverlapped ();
 121                         read_event = new ManualResetEvent (false);
 122 #if NET_2_0
 123                         ro.EventHandle = read_event.Handle;
 124 #else
 125                         ro.EventHandle = (int) read_event.Handle;
 126 #endif
 127                         read_overlapped = Marshal.AllocHGlobal (Marshal.SizeOf (typeof (NativeOverlapped)));
 128                         Marshal.StructureToPtr (ro, read_overlapped, true);
 129                 }
 130
 131                 public override bool CanRead {
 132                         get {
 133                                 return true;
 134                         }
 135                 }
 136
 137                 public override bool CanSeek {
 138                         get {
 139                                 return false;
 140                         }
 141                 }
 142
 143                 public override bool CanTimeout {
 144                         get {
 145                                 return true;
 146                         }
 147                 }
 148
 149                 public override bool CanWrite {
 150                         get {
 151                                 return true;
 152                         }
 153                 }
 154
 155                 public override int ReadTimeout {
 156                         get {
 157                                 return read_timeout;
 158                         }
 159                         set {
 160                                 if (value < 0 && value != SerialPort.InfiniteTimeout)
 161                                         throw new ArgumentOutOfRangeException ("value");
 162
 163                                 timeouts.SetValues (value, write_timeout);
 164                                 if (!SetCommTimeouts (handle, timeouts))
 165                                         ReportIOError (null);
 166
 167                                 read_timeout = value;
 168                         }
 169                 }
 170
 171                 public override int WriteTimeout {
 172                         get {
 173                                 return write_timeout;
 174                         }
 175                         set
 176                         {
 177                                 if (value < 0 && value != SerialPort.InfiniteTimeout)
 178                                         throw new ArgumentOutOfRangeException ("value");
 179
 180                                 timeouts.SetValues (read_timeout, value);
 181                                 if (!SetCommTimeouts (handle, timeouts))
 182                                         ReportIOError (null);
 183
 184                                 write_timeout = value;
 185                         }
 186                 }
 187
 188                 public override long Length {
 189                         get {
 190                                 throw new NotSupportedException ();
 191                         }
 192                 }
 193
 194                 public override long Position {
 195                         get {
 196                                 throw new NotSupportedException ();
 197                         }
 198                         set {
 199                                 throw new NotSupportedException ();
 200                         }
 201                 }
 202
 203                 [DllImport("kernel32", SetLastError = true)]
 204                 static extern bool CloseHandle (int handle);
 205
 206                 protected override void Dispose (bool disposing)
 207                 {
 208                         if (disposed)
 209                                 return;
 210
 211                         disposed = true;
 212                         CloseHandle (handle);
 213                         Marshal.FreeHGlobal (write_overlapped);
 214                         Marshal.FreeHGlobal (read_overlapped);
 215                 }
 216
 217                 void IDisposable.Dispose ()
 218                 {
 219                         Dispose (true);
 220                         GC.SuppressFinalize (this);
 221                 }
 222
 223                 public override void Close ()
 224                 {
 225                         ((IDisposable)this).Dispose ();
 226                 }
 227
 228                 ~WinSerialStream ()
 229                 {
 230                         Dispose (false);
 231                 }
 232
 233                 public override void Flush ()
 234                 {
 235                         CheckDisposed ();
 236                         // No dothing by now
 237                 }
 238
 239                 public override long Seek (long offset, SeekOrigin origin)
 240                 {
 241                         throw new NotSupportedException();
 242                 }
 243
 244                 public override void SetLength (long value)
 245                 {
 246                         throw new NotSupportedException();
 247                 }
 248
 249 #if !TARGET_JVM
 250                 [DllImport("kernel32", SetLastError = true)]
 251                         static extern unsafe bool ReadFile (int handle, byte* buffer, int bytes_to_read,
 252                                         out int bytes_read, IntPtr overlapped);
 253
 254                 [DllImport("kernel32", SetLastError = true)]
 255                         static extern unsafe bool GetOverlappedResult (int handle, IntPtr overlapped,
 256                                         ref int bytes_transfered, bool wait);
 257 #endif
 258
 259                 public override int Read ([In, Out] byte [] buffer, int offset, int count)
 260                 {
 261                         CheckDisposed ();
 262                         if (buffer == null)
 263                                 throw new ArgumentNullException ("buffer");
 264                         if (offset < 0 || count < 0)
 265                                 throw new ArgumentOutOfRangeException ("offset or count less than zero.");
 266
 267                         if (buffer.Length - offset < count )
 268                                 throw new ArgumentException ("offset+count",
 269                                                               "The size of the buffer is less than offset + count.");
 270
 271                         int bytes_read;
 272
 273                         unsafe {
 274                                 fixed (byte* ptr = buffer) {
 275                                         if (ReadFile (handle, ptr + offset, count, out bytes_read, read_overlapped))
 276                                                 return bytes_read;
 277
 278                                         // Test for overlapped behavior
 279                                         if (Marshal.GetLastWin32Error () != FileIOPending)
 280                                                 ReportIOError (null);
 281
 282                                         if (!GetOverlappedResult (handle, read_overlapped, ref bytes_read, true))
 283                                                 ReportIOError (null);
 284
 285                                 }
 286                         }
 287
 288                         if (bytes_read == 0)
 289                                 throw new TimeoutException (); // We didn't get any byte
 290
 291                         return bytes_read;
 292                 }
 293
 294 #if !TARGET_JVM
 295                 [DllImport("kernel32", SetLastError = true)]
 296                 static extern unsafe bool WriteFile (int handle, byte* buffer, int bytes_to_write,
 297                                 out int bytes_written, IntPtr overlapped);
 298 #endif
 299
 300                 public override void Write (byte [] buffer, int offset, int count)
 301                 {
 302                         CheckDisposed ();
 303                         if (buffer == null)
 304                                 throw new ArgumentNullException ("buffer");
 305
 306                         if (offset < 0 || count < 0)
 307                                 throw new ArgumentOutOfRangeException ();
 308
 309                         if (buffer.Length - offset < count)
 310                                 throw new ArgumentException ("offset+count",
 311                                                              "The size of the buffer is less than offset + count.");
 312
 313                         int bytes_written = 0;
 314
 315                         unsafe {
 316                                 fixed (byte* ptr = buffer) {
 317                                         if (WriteFile (handle, ptr + offset, count, out bytes_written, write_overlapped))
 318                                                 return;
 319                                         if (Marshal.GetLastWin32Error() != FileIOPending)
 320                                                 ReportIOError (null);
 321
 322                                         if (!GetOverlappedResult(handle, write_overlapped, ref bytes_written, true))
 323                                                 ReportIOError (null);
 324                                 }
 325                         }
 326
 327                         // If the operation timed out, then
 328                         // we transfered less bytes than the requested ones
 329                         if (bytes_written < count)
 330                                 throw new TimeoutException ();
 331                 }
 332
 333                 [DllImport("kernel32", SetLastError = true)]
 334                 static extern bool GetCommState (int handle, [Out] DCB dcb);
 335
 336                 [DllImport ("kernel32", SetLastError=true)]
 337                 static extern bool SetCommState (int handle, DCB dcb);
 338
 339                 public void SetAttributes (int baud_rate, Parity parity, int data_bits, StopBits bits, Handshake hs)
 340                 {
 341                         DCB dcb = new DCB ();
 342                         if (!GetCommState (handle, dcb))
 343                                 ReportIOError (null);
 344
 345                         dcb.SetValues (baud_rate, parity, data_bits, bits, hs);
 346                         if (!SetCommState (handle, dcb))
 347                                 ReportIOError (null);
 348                 }
 349
 350                 void ReportIOError(string optional_arg)
 351                 {
 352                         int error = Marshal.GetLastWin32Error ();
 353                         string message;
 354                         switch (error) {
 355                                 case 2:
 356                                 case 3:
 357                                         message = "The port `" + optional_arg + "' does not exist.";
 358                                         break;
 359                                 case 87:
 360                                         message = "Parameter is incorrect.";
 361                                         break;
 362                                 default:
 363                                         // As fallback, we show the win32 error
 364                                         message = new Win32Exception ().Message;
 365                                         break;
 366                         }
 367
 368                         throw new IOException (message);
 369                 }
 370
 371                 void CheckDisposed ()
 372                 {
 373                         if (disposed)
 374                                 throw new ObjectDisposedException (GetType ().FullName);
 375                 }
 376
 377                 // ISerialStream members
 378                 public void DiscardInBuffer ()
 379                 {
 380                         if (!PurgeComm (handle, PurgeRxClear))
 381                                 ReportIOError (null);
 382                 }
 383
 384                 public void DiscardOutBuffer ()
 385                 {
 386                         if (!PurgeComm (handle, PurgeRxClear))
 387                                 ReportIOError (null);
 388                 }
 389
 390                 [DllImport ("kernel32", SetLastError=true)]
 391                 static extern bool ClearCommError (int handle, out CommStat stat);
 392
 393                 public int BytesToRead {
 394                         get {
 395                                 CommStat stat;
 396                                 if (!ClearCommError (handle, out stat))
 397                                         ReportIOError (null);
 398
 399                                 return (int)stat.BytesIn;
 400                         }
 401                 }
 402
 403                 public int BytesToWrite {
 404                         get {
 405                                 CommStat stat;
 406                                 if (!ClearCommError (handle, out stat))
 407                                         ReportIOError (null);
 408
 409                                 return (int)stat.BytesOut;
 410                         }
 411                 }
 412
 413                 [DllImport ("kernel32", SetLastError=true)]
 414                 static extern bool GetCommModemStatus (int handle, out uint flags);
 415
 416                 public SerialSignal GetSignals ()
 417                 {
 418                         uint flags;
 419                         if (!GetCommModemStatus (handle, out flags))
 420                                 ReportIOError (null);
 421
 422                         SerialSignal signals = SerialSignal.None;
 423                         if ((flags & RsldOn) != 0)
 424                                 signals |= SerialSignal.Cd;
 425                         if ((flags & CtsOn) != 0)
 426                                 signals |= SerialSignal.Cts;
 427                         if ((flags & DsrOn) != 0)
 428                                 signals |= SerialSignal.Dsr;
 429
 430                         return signals;
 431                 }
 432
 433                 [DllImport ("kernel32", SetLastError=true)]
 434                 static extern bool EscapeCommFunction (int handle, uint flags);
 435
 436                 public void SetSignal (SerialSignal signal, bool value)
 437                 {
 438                         if (signal != SerialSignal.Rts && signal != SerialSignal.Dtr)
 439                                 throw new Exception ("Wrong internal value");
 440
 441                         uint flag;
 442                         if (signal == SerialSignal.Rts)
 443                                 if (value)
 444                                         flag = SetRts;
 445                                 else
 446                                         flag = ClearRts;
 447                         else
 448                                 if (value)
 449                                         flag = SetDtr;
 450                                 else
 451                                         flag = ClearDtr;
 452
 453                         if (!EscapeCommFunction (handle, flag))
 454                                 ReportIOError (null);
 455                 }
 456
 457                 public void SetBreakState (bool value)
 458                 {
 459                         if (!EscapeCommFunction (handle, value ? SetBreak : ClearBreak))
 460                                 ReportIOError (null);
 461                 }
 462
 463         }
 464
 465         [StructLayout (LayoutKind.Sequential)]
 466         class DCB
 467         {
 468                 public int dcb_length;
 469                 public int baud_rate;
 470                 public int flags;
 471                 public short w_reserved;
 472                 public short xon_lim;
 473                 public short xoff_lim;
 474                 public byte byte_size;
 475                 public byte parity;
 476                 public byte stop_bits;
 477                 public byte xon_char;
 478                 public byte xoff_char;
 479                 public byte error_char;
 480                 public byte eof_char;
 481                 public byte evt_char;
 482                 public short w_reserved1;
 483
 484                 // flags:
 485                 //const int fBinary = 0x0001;
 486                 //const int fParity = 0x0002;
 487                 const int fOutxCtsFlow = 0x0004;
 488                 //const int fOutxDsrFlow1 = 0x0008;
 489                 //const int fOutxDsrFlow2 = 0x0010;
 490                 //const int fDtrControl = 0x00020;
 491                 //const int fDsrSensitivity = 0x0040;
 492                 //const int fTXContinueOnXoff = 0x0080;
 493                 const int fOutX = 0x0100;
 494                 const int fInX = 0x0200;
 495                 //const int fErrorChar = 0x0400;
 496                 //const int fNull = 0x0800;
 497                 //const int fRtsControl1 = 0x1000;
 498                 const int fRtsControl2 = 0x2000;
 499                 //const int fAbortOnError = 0x4000;
 500
 501                 public void SetValues (int baud_rate, Parity parity, int byte_size, StopBits sb, Handshake hs)
 502                 {
 503                         switch (sb) {
 504                                 case StopBits.One:
 505                                         stop_bits = 0;
 506                                         break;
 507                                 case StopBits.OnePointFive:
 508                                         stop_bits = 1;
 509                                         break;
 510                                 case StopBits.Two:
 511                                         stop_bits = 2;
 512                                         break;
 513                                 default: // Shouldn't happen
 514                                         break;
 515                         }
 516
 517                         this.baud_rate = baud_rate;
 518                         this.parity = (byte)parity;
 519                         this.byte_size = (byte)byte_size;
 520
 521                         // Clear Handshake flags
 522                         flags &= ~(fOutxCtsFlow | fOutX | fInX | fRtsControl2);
 523
 524                         // Set Handshake flags
 525                         switch (hs)
 526                         {
 527                                 case Handshake.None:
 528                                         break;
 529                                 case Handshake.XOnXOff:
 530                                         flags |= fOutX | fInX;
 531                                         break;
 532                                 case Handshake.RequestToSend:
 533                                         flags |= fOutxCtsFlow | fRtsControl2;
 534                                         break;
 535                                 case Handshake.RequestToSendXOnXOff:
 536                                         flags |= fOutxCtsFlow | fOutX | fInX | fRtsControl2;
 537                                         break;
 538                                 default: // Shouldn't happen
 539                                         break;
 540                         }
 541                 }
 542         }
 543
 544         [StructLayout (LayoutKind.Sequential)]
 545         class Timeouts
 546         {
 547                 public uint ReadIntervalTimeout;
 548                 public uint ReadTotalTimeoutMultiplier;
 549                 public uint ReadTotalTimeoutConstant;
 550                 public uint WriteTotalTimeoutMultiplier;
 551                 public uint WriteTotalTimeoutConstant;
 552
 553                 public const uint MaxDWord = 0xFFFFFFFF;
 554
 555                 public Timeouts (int read_timeout, int write_timeout)
 556                 {
 557                         SetValues (read_timeout, write_timeout);
 558                 }
 559
 560                 public void SetValues (int read_timeout, int write_timeout)
 561                 {
 562                         // FIXME: The windows api docs are not very clear about read timeouts,
 563                         // and we have to simulate infinite with a big value (uint.MaxValue - 1)
 564                         ReadIntervalTimeout = MaxDWord;
 565                         ReadTotalTimeoutMultiplier = MaxDWord;
 566                         ReadTotalTimeoutConstant = (read_timeout == -1 ? MaxDWord - 1 : (uint) read_timeout);
 567
 568                         WriteTotalTimeoutMultiplier = 0;
 569                         WriteTotalTimeoutConstant = (write_timeout == -1 ? MaxDWord : (uint) write_timeout);
 570                 }
 571
 572         }
 573
 574         [StructLayout (LayoutKind.Sequential)]
 575         class CommStat
 576         {
 577                 public uint flags;
 578                 public uint BytesIn;
 579                 public uint BytesOut;
 580         }
 581 }
 582
 583 #endif
 584