gdb/ser-mingw.c

   1 /* Serial interface for local (hardwired) serial ports on Windows systems
   2
   3    Copyright (C) 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "defs.h"
  21 #include "serial.h"
  22 #include "ser-base.h"
  23 #include "ser-tcp.h"
  24
  25 #include <windows.h>
  26 #include <conio.h>
  27
  28 #include <fcntl.h>
  29 #include <unistd.h>
  30 #include <sys/types.h>
  31
  32 #include "gdb_assert.h"
  33 #include "gdb_string.h"
  34
  35 #include "command.h"
  36
  37 void _initialize_ser_windows (void);
  38
  39 struct ser_windows_state
  40 {
  41   int in_progress;
  42   OVERLAPPED ov;
  43   DWORD lastCommMask;
  44   HANDLE except_event;
  45 };
  46
  47 /* Open up a real live device for serial I/O.  */
  48
  49 static int
  50 ser_windows_open (struct serial *scb, const char *name)
  51 {
  52   HANDLE h;
  53   struct ser_windows_state *state;
  54   COMMTIMEOUTS timeouts;
  55
  56   h = CreateFile (name, GENERIC_READ | GENERIC_WRITE, 0, NULL,
  57                   OPEN_EXISTING, FILE_FLAG_OVERLAPPED, NULL);
  58   if (h == INVALID_HANDLE_VALUE)
  59     {
  60       errno = ENOENT;
  61       return -1;
  62     }
  63
  64   scb->fd = _open_osfhandle ((intptr_t) h, O_RDWR);
  65   if (scb->fd < 0)
  66     {
  67       errno = ENOENT;
  68       return -1;
  69     }
  70
  71   if (!SetCommMask (h, EV_RXCHAR))
  72     {
  73       errno = EINVAL;
  74       return -1;
  75     }
  76
  77   timeouts.ReadIntervalTimeout = MAXDWORD;
  78   timeouts.ReadTotalTimeoutConstant = 0;
  79   timeouts.ReadTotalTimeoutMultiplier = 0;
  80   timeouts.WriteTotalTimeoutConstant = 0;
  81   timeouts.WriteTotalTimeoutMultiplier = 0;
  82   if (!SetCommTimeouts (h, &timeouts))
  83     {
  84       errno = EINVAL;
  85       return -1;
  86     }
  87
  88   state = xmalloc (sizeof (struct ser_windows_state));
  89   memset (state, 0, sizeof (struct ser_windows_state));
  90   scb->state = state;
  91
  92   /* Create a manual reset event to watch the input buffer.  */
  93   state->ov.hEvent = CreateEvent (0, TRUE, FALSE, 0);
  94
  95   /* Create a (currently unused) handle to record exceptions.  */
  96   state->except_event = CreateEvent (0, TRUE, FALSE, 0);
  97
  98   return 0;
  99 }
 100
 101 /* Wait for the output to drain away, as opposed to flushing (discarding)
 102    it.  */
 103
 104 static int
 105 ser_windows_drain_output (struct serial *scb)
 106 {
 107   HANDLE h = (HANDLE) _get_osfhandle (scb->fd);
 108
 109   return (FlushFileBuffers (h) != 0) ? 0 : -1;
 110 }
 111
 112 static int
 113 ser_windows_flush_output (struct serial *scb)
 114 {
 115   HANDLE h = (HANDLE) _get_osfhandle (scb->fd);
 116
 117   return (PurgeComm (h, PURGE_TXCLEAR) != 0) ? 0 : -1;
 118 }
 119
 120 static int
 121 ser_windows_flush_input (struct serial *scb)
 122 {
 123   HANDLE h = (HANDLE) _get_osfhandle (scb->fd);
 124
 125   return (PurgeComm (h, PURGE_RXCLEAR) != 0) ? 0 : -1;
 126 }
 127
 128 static int
 129 ser_windows_send_break (struct serial *scb)
 130 {
 131   HANDLE h = (HANDLE) _get_osfhandle (scb->fd);
 132
 133   if (SetCommBreak (h) == 0)
 134     return -1;
 135
 136   /* Delay for 250 milliseconds.  */
 137   Sleep (250);
 138
 139   if (ClearCommBreak (h))
 140     return -1;
 141
 142   return 0;
 143 }
 144
 145 static void
 146 ser_windows_raw (struct serial *scb)
 147 {
 148   HANDLE h = (HANDLE) _get_osfhandle (scb->fd);
 149   DCB state;
 150
 151   if (GetCommState (h, &state) == 0)
 152     return;
 153
 154   state.fParity = FALSE;
 155   state.fOutxCtsFlow = FALSE;
 156   state.fOutxDsrFlow = FALSE;
 157   state.fDtrControl = DTR_CONTROL_ENABLE;
 158   state.fDsrSensitivity = FALSE;
 159   state.fOutX = FALSE;
 160   state.fInX = FALSE;
 161   state.fNull = FALSE;
 162   state.fAbortOnError = FALSE;
 163   state.ByteSize = 8;
 164   state.Parity = NOPARITY;
 165
 166   scb->current_timeout = 0;
 167
 168   if (SetCommState (h, &state) == 0)
 169     warning (_("SetCommState failed\n"));
 170 }
 171
 172 static int
 173 ser_windows_setstopbits (struct serial *scb, int num)
 174 {
 175   HANDLE h = (HANDLE) _get_osfhandle (scb->fd);
 176   DCB state;
 177
 178   if (GetCommState (h, &state) == 0)
 179     return -1;
 180
 181   switch (num)
 182     {
 183     case SERIAL_1_STOPBITS:
 184       state.StopBits = ONESTOPBIT;
 185       break;
 186     case SERIAL_1_AND_A_HALF_STOPBITS:
 187       state.StopBits = ONE5STOPBITS;
 188       break;
 189     case SERIAL_2_STOPBITS:
 190       state.StopBits = TWOSTOPBITS;
 191       break;
 192     default:
 193       return 1;
 194     }
 195
 196   return (SetCommState (h, &state) != 0) ? 0 : -1;
 197 }
 198
 199 static int
 200 ser_windows_setbaudrate (struct serial *scb, int rate)
 201 {
 202   HANDLE h = (HANDLE) _get_osfhandle (scb->fd);
 203   DCB state;
 204
 205   if (GetCommState (h, &state) == 0)
 206     return -1;
 207
 208   state.BaudRate = rate;
 209
 210   return (SetCommState (h, &state) != 0) ? 0 : -1;
 211 }
 212
 213 static void
 214 ser_windows_close (struct serial *scb)
 215 {
 216   struct ser_windows_state *state;
 217
 218   /* Stop any pending selects.  */
 219   CancelIo ((HANDLE) _get_osfhandle (scb->fd));
 220   state = scb->state;
 221   CloseHandle (state->ov.hEvent);
 222   CloseHandle (state->except_event);
 223
 224   if (scb->fd < 0)
 225     return;
 226
 227   close (scb->fd);
 228   scb->fd = -1;
 229
 230   xfree (scb->state);
 231 }
 232
 233 static void
 234 ser_windows_wait_handle (struct serial *scb, HANDLE *read, HANDLE *except)
 235 {
 236   struct ser_windows_state *state;
 237   COMSTAT status;
 238   DWORD errors;
 239   HANDLE h = (HANDLE) _get_osfhandle (scb->fd);
 240
 241   state = scb->state;
 242
 243   *except = state->except_event;
 244   *read = state->ov.hEvent;
 245
 246   if (state->in_progress)
 247     return;
 248
 249   /* Reset the mask - we are only interested in any characters which
 250      arrive after this point, not characters which might have arrived
 251      and already been read.  */
 252
 253   /* This really, really shouldn't be necessary - just the second one.
 254      But otherwise an internal flag for EV_RXCHAR does not get
 255      cleared, and we get a duplicated event, if the last batch
 256      of characters included at least two arriving close together.  */
 257   if (!SetCommMask (h, 0))
 258     warning (_("ser_windows_wait_handle: reseting mask failed"));
 259
 260   if (!SetCommMask (h, EV_RXCHAR))
 261     warning (_("ser_windows_wait_handle: reseting mask failed (2)"));
 262
 263   /* There's a potential race condition here; we must check cbInQue
 264      and not wait if that's nonzero.  */
 265
 266   ClearCommError (h, &errors, &status);
 267   if (status.cbInQue > 0)
 268     {
 269       SetEvent (state->ov.hEvent);
 270       return;
 271     }
 272
 273   state->in_progress = 1;
 274   ResetEvent (state->ov.hEvent);
 275   state->lastCommMask = -2;
 276   if (WaitCommEvent (h, &state->lastCommMask, &state->ov))
 277     {
 278       gdb_assert (state->lastCommMask & EV_RXCHAR);
 279       SetEvent (state->ov.hEvent);
 280     }
 281   else
 282     gdb_assert (GetLastError () == ERROR_IO_PENDING);
 283 }
 284
 285 static int
 286 ser_windows_read_prim (struct serial *scb, size_t count)
 287 {
 288   struct ser_windows_state *state;
 289   OVERLAPPED ov;
 290   DWORD bytes_read, bytes_read_tmp;
 291   HANDLE h;
 292   gdb_byte *p;
 293
 294   state = scb->state;
 295   if (state->in_progress)
 296     {
 297       WaitForSingleObject (state->ov.hEvent, INFINITE);
 298       state->in_progress = 0;
 299       ResetEvent (state->ov.hEvent);
 300     }
 301
 302   memset (&ov, 0, sizeof (OVERLAPPED));
 303   ov.hEvent = CreateEvent (0, FALSE, FALSE, 0);
 304   h = (HANDLE) _get_osfhandle (scb->fd);
 305
 306   if (!ReadFile (h, scb->buf, /* count */ 1, &bytes_read, &ov))
 307     {
 308       if (GetLastError () != ERROR_IO_PENDING
 309           || !GetOverlappedResult (h, &ov, &bytes_read, TRUE))
 310         bytes_read = -1;
 311     }
 312
 313   CloseHandle (ov.hEvent);
 314   return bytes_read;
 315 }
 316
 317 static int
 318 ser_windows_write_prim (struct serial *scb, const void *buf, size_t len)
 319 {
 320   struct ser_windows_state *state;
 321   OVERLAPPED ov;
 322   DWORD bytes_written;
 323   HANDLE h;
 324
 325   memset (&ov, 0, sizeof (OVERLAPPED));
 326   ov.hEvent = CreateEvent (0, FALSE, FALSE, 0);
 327   h = (HANDLE) _get_osfhandle (scb->fd);
 328   if (!WriteFile (h, buf, len, &bytes_written, &ov))
 329     {
 330       if (GetLastError () != ERROR_IO_PENDING
 331           || !GetOverlappedResult (h, &ov, &bytes_written, TRUE))
 332         bytes_written = -1;
 333     }
 334
 335   CloseHandle (ov.hEvent);
 336   return bytes_written;
 337 }
 338
 339 /* On Windows, gdb_select is implemented using WaitForMulpleObjects.
 340    A "select thread" is created for each file descriptor.  These
 341    threads looks for activity on the corresponding descriptor, using
 342    whatever techniques are appropriate for the descriptor type.  When
 343    that activity occurs, the thread signals an appropriate event,
 344    which wakes up WaitForMultipleObjects.
 345
 346    Each select thread is in one of two states: stopped or started.
 347    Select threads begin in the stopped state.  When gdb_select is
 348    called, threads corresponding to the descriptors of interest are
 349    started by calling a wait_handle function.  Each thread that
 350    notices activity signals the appropriate event and then reenters
 351    the stopped state.  Before gdb_select returns it calls the
 352    wait_handle_done functions, which return the threads to the stopped
 353    state.  */
 354
 355 enum select_thread_state {
 356   STS_STARTED,
 357   STS_STOPPED
 358 };
 359
 360 struct ser_console_state
 361 {
 362   /* Signaled by the select thread to indicate that data is available
 363      on the file descriptor.  */
 364   HANDLE read_event;
 365   /* Signaled by the select thread to indicate that an exception has
 366      occurred on the file descriptor.  */
 367   HANDLE except_event;
 368   /* Signaled by the select thread to indicate that it has entered the
 369      started state.  HAVE_STARTED and HAVE_STOPPED are never signaled
 370      simultaneously.  */
 371   HANDLE have_started;
 372   /* Signaled by the select thread to indicate that it has stopped,
 373      either because data is available (and READ_EVENT is signaled),
 374      because an exception has occurred (and EXCEPT_EVENT is signaled),
 375      or because STOP_SELECT was signaled.  */
 376   HANDLE have_stopped;
 377
 378   /* Signaled by the main program to tell the select thread to enter
 379      the started state.  */
 380   HANDLE start_select;
 381   /* Signaled by the main program to tell the select thread to enter
 382      the stopped state. */
 383   HANDLE stop_select;
 384   /* Signaled by the main program to tell the select thread to
 385      exit.  */
 386   HANDLE exit_select;
 387
 388   /* The handle for the select thread.  */
 389   HANDLE thread;
 390   /* The state of the select thread.  This field is only accessed in
 391      the main program, never by the select thread itself.  */
 392   enum select_thread_state thread_state;
 393 };
 394
 395 /* Called by a select thread to enter the stopped state.  This
 396    function does not return until the thread has re-entered the
 397    started state.  */
 398 static void
 399 select_thread_wait (struct ser_console_state *state)
 400 {
 401   HANDLE wait_events[2];
 402
 403   /* There are two things that can wake us up: a request that we enter
 404      the started state, or that we exit this thread.  */
 405   wait_events[0] = state->start_select;
 406   wait_events[1] = state->exit_select;
 407   if (WaitForMultipleObjects (2, wait_events, FALSE, INFINITE)
 408       != WAIT_OBJECT_0)
 409     /* Either the EXIT_SELECT event was signaled (requesting that the
 410        thread exit) or an error has occurred.  In either case, we exit
 411        the thread.  */
 412     ExitThread (0);
 413
 414   /* We are now in the started state.  */
 415   SetEvent (state->have_started);
 416 }
 417
 418 typedef DWORD WINAPI (*thread_fn_type)(void *);
 419
 420 /* Create a new select thread for SCB executing THREAD_FN.  The STATE
 421    will be filled in by this function before return.  */
 422 void
 423 create_select_thread (thread_fn_type thread_fn,
 424                       struct serial *scb,
 425                       struct ser_console_state *state)
 426 {
 427   DWORD threadId;
 428
 429   /* Create all of the events.  These are all auto-reset events.  */
 430   state->read_event = CreateEvent (NULL, FALSE, FALSE, NULL);
 431   state->except_event = CreateEvent (NULL, FALSE, FALSE, NULL);
 432   state->have_started = CreateEvent (NULL, FALSE, FALSE, NULL);
 433   state->have_stopped = CreateEvent (NULL, FALSE, FALSE, NULL);
 434   state->start_select = CreateEvent (NULL, FALSE, FALSE, NULL);
 435   state->stop_select = CreateEvent (NULL, FALSE, FALSE, NULL);
 436   state->exit_select = CreateEvent (NULL, FALSE, FALSE, NULL);
 437
 438   state->thread = CreateThread (NULL, 0, thread_fn, scb, 0, &threadId);
 439   /* The thread begins in the stopped state.  */
 440   state->thread_state = STS_STOPPED;
 441 }
 442
 443 /* Destroy the select thread indicated by STATE.  */
 444 static void
 445 destroy_select_thread (struct ser_console_state *state)
 446 {
 447   /* Ask the thread to exit.  */
 448   SetEvent (state->exit_select);
 449   /* Wait until it does.  */
 450   WaitForSingleObject (state->thread, INFINITE);
 451
 452   /* Destroy the events.  */
 453   CloseHandle (state->read_event);
 454   CloseHandle (state->except_event);
 455   CloseHandle (state->have_started);
 456   CloseHandle (state->have_stopped);
 457   CloseHandle (state->start_select);
 458   CloseHandle (state->stop_select);
 459   CloseHandle (state->exit_select);
 460 }
 461
 462 /* Called by gdb_select to start the select thread indicated by STATE.
 463    This function does not return until the thread has started.  */
 464 static void
 465 start_select_thread (struct ser_console_state *state)
 466 {
 467   /* Ask the thread to start.  */
 468   SetEvent (state->start_select);
 469   /* Wait until it does.  */
 470   WaitForSingleObject (state->have_started, INFINITE);
 471   /* The thread is now started.  */
 472   state->thread_state = STS_STARTED;
 473 }
 474
 475 /* Called by gdb_select to stop the select thread indicated by STATE.
 476    This function does not return until the thread has stopped.  */
 477 static void
 478 stop_select_thread (struct ser_console_state *state)
 479 {
 480   /* If the thread is already in the stopped state, we have nothing to
 481      do.  Some of the wait_handle functions avoid calling
 482      start_select_thread if they notice activity on the relevant file
 483      descriptors.  The wait_handle_done functions still call
 484      stop_select_thread -- but it is already stopped.  */
 485   if (state->thread_state != STS_STARTED)
 486     return;
 487   /* Ask the thread to stop.  */
 488   SetEvent (state->stop_select);
 489   /* Wait until it does.  */
 490   WaitForSingleObject (state->have_stopped, INFINITE);
 491   /* The thread is now stopped.  */
 492   state->thread_state = STS_STOPPED;
 493 }
 494
 495 static DWORD WINAPI
 496 console_select_thread (void *arg)
 497 {
 498   struct serial *scb = arg;
 499   struct ser_console_state *state;
 500   int event_index;
 501   HANDLE h;
 502
 503   state = scb->state;
 504   h = (HANDLE) _get_osfhandle (scb->fd);
 505
 506   while (1)
 507     {
 508       HANDLE wait_events[2];
 509       INPUT_RECORD record;
 510       DWORD n_records;
 511
 512       select_thread_wait (state);
 513
 514       while (1)
 515         {
 516           wait_events[0] = state->stop_select;
 517           wait_events[1] = h;
 518
 519           event_index = WaitForMultipleObjects (2, wait_events, FALSE, INFINITE);
 520
 521           if (event_index == WAIT_OBJECT_0
 522               || WaitForSingleObject (state->stop_select, 0) == WAIT_OBJECT_0)
 523             break;
 524
 525           if (event_index != WAIT_OBJECT_0 + 1)
 526             {
 527               /* Wait must have failed; assume an error has occured, e.g.
 528                  the handle has been closed.  */
 529               SetEvent (state->except_event);
 530               break;
 531             }
 532
 533           /* We've got a pending event on the console.  See if it's
 534              of interest.  */
 535           if (!PeekConsoleInput (h, &record, 1, &n_records) || n_records != 1)
 536             {
 537               /* Something went wrong.  Maybe the console is gone.  */
 538               SetEvent (state->except_event);
 539               break;
 540             }
 541
 542           if (record.EventType == KEY_EVENT && record.Event.KeyEvent.bKeyDown)
 543             {
 544               WORD keycode = record.Event.KeyEvent.wVirtualKeyCode;
 545
 546               /* Ignore events containing only control keys.  We must
 547                  recognize "enhanced" keys which we are interested in
 548                  reading via getch, if they do not map to ASCII.  But we
 549                  do not want to report input available for e.g. the
 550                  control key alone.  */
 551
 552               if (record.Event.KeyEvent.uChar.AsciiChar != 0
 553                   || keycode == VK_PRIOR
 554                   || keycode == VK_NEXT
 555                   || keycode == VK_END
 556                   || keycode == VK_HOME
 557                   || keycode == VK_LEFT
 558                   || keycode == VK_UP
 559                   || keycode == VK_RIGHT
 560                   || keycode == VK_DOWN
 561                   || keycode == VK_INSERT
 562                   || keycode == VK_DELETE)
 563                 {
 564                   /* This is really a keypress.  */
 565                   SetEvent (state->read_event);
 566                   break;
 567                 }
 568             }
 569
 570           /* Otherwise discard it and wait again.  */
 571           ReadConsoleInput (h, &record, 1, &n_records);
 572         }
 573
 574       SetEvent(state->have_stopped);
 575     }
 576   return 0;
 577 }
 578
 579 static int
 580 fd_is_pipe (int fd)
 581 {
 582   if (PeekNamedPipe ((HANDLE) _get_osfhandle (fd), NULL, 0, NULL, NULL, NULL))
 583     return 1;
 584   else
 585     return 0;
 586 }
 587
 588 static int
 589 fd_is_file (int fd)
 590 {
 591   if (GetFileType ((HANDLE) _get_osfhandle (fd)) == FILE_TYPE_DISK)
 592     return 1;
 593   else
 594     return 0;
 595 }
 596
 597 static DWORD WINAPI
 598 pipe_select_thread (void *arg)
 599 {
 600   struct serial *scb = arg;
 601   struct ser_console_state *state;
 602   int event_index;
 603   HANDLE h;
 604
 605   state = scb->state;
 606   h = (HANDLE) _get_osfhandle (scb->fd);
 607
 608   while (1)
 609     {
 610       DWORD n_avail;
 611
 612       select_thread_wait (state);
 613
 614       /* Wait for something to happen on the pipe.  */
 615       while (1)
 616         {
 617           if (!PeekNamedPipe (h, NULL, 0, NULL, &n_avail, NULL))
 618             {
 619               SetEvent (state->except_event);
 620               break;
 621             }
 622
 623           if (n_avail > 0)
 624             {
 625               SetEvent (state->read_event);
 626               break;
 627             }
 628
 629           /* Delay 10ms before checking again, but allow the stop
 630              event to wake us.  */
 631           if (WaitForSingleObject (state->stop_select, 10) == WAIT_OBJECT_0)
 632             break;
 633         }
 634
 635       SetEvent (state->have_stopped);
 636     }
 637   return 0;
 638 }
 639
 640 static DWORD WINAPI
 641 file_select_thread (void *arg)
 642 {
 643   struct serial *scb = arg;
 644   struct ser_console_state *state;
 645   int event_index;
 646   HANDLE h;
 647
 648   state = scb->state;
 649   h = (HANDLE) _get_osfhandle (scb->fd);
 650
 651   while (1)
 652     {
 653       select_thread_wait (state);
 654
 655       if (SetFilePointer (h, 0, NULL, FILE_CURRENT) == INVALID_SET_FILE_POINTER)
 656         SetEvent (state->except_event);
 657       else
 658         SetEvent (state->read_event);
 659
 660       SetEvent (state->have_stopped);
 661     }
 662   return 0;
 663 }
 664
 665 static void
 666 ser_console_wait_handle (struct serial *scb, HANDLE *read, HANDLE *except)
 667 {
 668   struct ser_console_state *state = scb->state;
 669
 670   if (state == NULL)
 671     {
 672       thread_fn_type thread_fn;
 673       int is_tty;
 674
 675       is_tty = isatty (scb->fd);
 676       if (!is_tty && !fd_is_file (scb->fd) && !fd_is_pipe (scb->fd))
 677         {
 678           *read = NULL;
 679           *except = NULL;
 680           return;
 681         }
 682
 683       state = xmalloc (sizeof (struct ser_console_state));
 684       memset (state, 0, sizeof (struct ser_console_state));
 685       scb->state = state;
 686
 687       if (is_tty)
 688         thread_fn = console_select_thread;
 689       else if (fd_is_pipe (scb->fd))
 690         thread_fn = pipe_select_thread;
 691       else
 692         thread_fn = file_select_thread;
 693
 694       create_select_thread (thread_fn, scb, state);
 695     }
 696
 697   *read = state->read_event;
 698   *except = state->except_event;
 699
 700   /* Start from a blank state.  */
 701   ResetEvent (state->read_event);
 702   ResetEvent (state->except_event);
 703   ResetEvent (state->stop_select);
 704
 705   /* First check for a key already in the buffer.  If there is one,
 706      we don't need a thread.  This also catches the second key of
 707      multi-character returns from getch, for instance for arrow
 708      keys.  The second half is in a C library internal buffer,
 709      and PeekConsoleInput will not find it.  */
 710   if (_kbhit ())
 711     {
 712       SetEvent (state->read_event);
 713       return;
 714     }
 715
 716   /* Otherwise, start the select thread.  */
 717   start_select_thread (state);
 718 }
 719
 720 static void
 721 ser_console_done_wait_handle (struct serial *scb)
 722 {
 723   struct ser_console_state *state = scb->state;
 724
 725   if (state == NULL)
 726     return;
 727
 728   stop_select_thread (state);
 729 }
 730
 731 static void
 732 ser_console_close (struct serial *scb)
 733 {
 734   struct ser_console_state *state = scb->state;
 735
 736   if (scb->state)
 737     {
 738       destroy_select_thread (state);
 739       xfree (scb->state);
 740     }
 741 }
 742
 743 struct ser_console_ttystate
 744 {
 745   int is_a_tty;
 746 };
 747
 748 static serial_ttystate
 749 ser_console_get_tty_state (struct serial *scb)
 750 {
 751   if (isatty (scb->fd))
 752     {
 753       struct ser_console_ttystate *state;
 754       state = (struct ser_console_ttystate *) xmalloc (sizeof *state);
 755       state->is_a_tty = 1;
 756       return state;
 757     }
 758   else
 759     return NULL;
 760 }
 761
 762 struct pipe_state
 763 {
 764   /* Since we use the pipe_select_thread for our select emulation,
 765      we need to place the state structure it requires at the front
 766      of our state.  */
 767   struct ser_console_state wait;
 768
 769   /* The pex obj for our (one-stage) pipeline.  */
 770   struct pex_obj *pex;
 771
 772   /* Streams for the pipeline's input and output.  */
 773   FILE *input, *output;
 774 };
 775
 776 static struct pipe_state *
 777 make_pipe_state (void)
 778 {
 779   struct pipe_state *ps = XMALLOC (struct pipe_state);
 780
 781   memset (ps, 0, sizeof (*ps));
 782   ps->wait.read_event = INVALID_HANDLE_VALUE;
 783   ps->wait.except_event = INVALID_HANDLE_VALUE;
 784   ps->wait.start_select = INVALID_HANDLE_VALUE;
 785   ps->wait.stop_select = INVALID_HANDLE_VALUE;
 786
 787   return ps;
 788 }
 789
 790 static void
 791 free_pipe_state (struct pipe_state *ps)
 792 {
 793   int saved_errno = errno;
 794
 795   if (ps->wait.read_event != INVALID_HANDLE_VALUE)
 796     destroy_select_thread (&ps->wait);
 797
 798   /* Close the pipe to the child.  We must close the pipe before
 799      calling pex_free because pex_free will wait for the child to exit
 800      and the child will not exit until the pipe is closed.  */
 801   if (ps->input)
 802     fclose (ps->input);
 803   if (ps->pex)
 804     pex_free (ps->pex);
 805   /* pex_free closes ps->output.  */
 806
 807   xfree (ps);
 808
 809   errno = saved_errno;
 810 }
 811
 812 static void
 813 cleanup_pipe_state (void *untyped)
 814 {
 815   struct pipe_state *ps = untyped;
 816
 817   free_pipe_state (ps);
 818 }
 819
 820 static int
 821 pipe_windows_open (struct serial *scb, const char *name)
 822 {
 823   struct pipe_state *ps;
 824   FILE *pex_stderr;
 825   char **argv;
 826   struct cleanup *back_to;
 827
 828   if (name == NULL)
 829     error_no_arg (_("child command"));
 830
 831   argv = gdb_buildargv (name);
 832   back_to = make_cleanup_freeargv (argv);
 833
 834   if (! argv[0] || argv[0][0] == '\0')
 835     error ("missing child command");
 836
 837   ps = make_pipe_state ();
 838   make_cleanup (cleanup_pipe_state, ps);
 839
 840   ps->pex = pex_init (PEX_USE_PIPES, "target remote pipe", NULL);
 841   if (! ps->pex)
 842     goto fail;
 843   ps->input = pex_input_pipe (ps->pex, 1);
 844   if (! ps->input)
 845     goto fail;
 846
 847   {
 848     int err;
 849     const char *err_msg
 850       = pex_run (ps->pex, PEX_SEARCH | PEX_BINARY_INPUT | PEX_BINARY_OUTPUT
 851                  | PEX_STDERR_TO_PIPE,
 852                  argv[0], argv, NULL, NULL,
 853                  &err);
 854
 855     if (err_msg)
 856       {
 857         /* Our caller expects us to return -1, but all they'll do with
 858            it generally is print the message based on errno.  We have
 859            all the same information here, plus err_msg provided by
 860            pex_run, so we just raise the error here.  */
 861         if (err)
 862           error ("error starting child process '%s': %s: %s",
 863                  name, err_msg, safe_strerror (err));
 864         else
 865           error ("error starting child process '%s': %s",
 866                  name, err_msg);
 867       }
 868   }
 869
 870   ps->output = pex_read_output (ps->pex, 1);
 871   if (! ps->output)
 872     goto fail;
 873   scb->fd = fileno (ps->output);
 874
 875   pex_stderr = pex_read_err (ps->pex, 1);
 876   if (! pex_stderr)
 877     goto fail;
 878   scb->error_fd = fileno (pex_stderr);
 879
 880   scb->state = (void *) ps;
 881
 882   discard_cleanups (back_to);
 883   return 0;
 884
 885  fail:
 886   do_cleanups (back_to);
 887   return -1;
 888 }
 889
 890
 891 static void
 892 pipe_windows_close (struct serial *scb)
 893 {
 894   struct pipe_state *ps = scb->state;
 895
 896   /* In theory, we should try to kill the subprocess here, but the pex
 897      interface doesn't give us enough information to do that.  Usually
 898      closing the input pipe will get the message across.  */
 899
 900   free_pipe_state (ps);
 901 }
 902
 903
 904 static int
 905 pipe_windows_read (struct serial *scb, size_t count)
 906 {
 907   HANDLE pipeline_out = (HANDLE) _get_osfhandle (scb->fd);
 908   DWORD available;
 909   DWORD bytes_read;
 910
 911   if (pipeline_out == INVALID_HANDLE_VALUE)
 912     return -1;
 913
 914   if (! PeekNamedPipe (pipeline_out, NULL, 0, NULL, &available, NULL))
 915     return -1;
 916
 917   if (count > available)
 918     count = available;
 919
 920   if (! ReadFile (pipeline_out, scb->buf, count, &bytes_read, NULL))
 921     return -1;
 922
 923   return bytes_read;
 924 }
 925
 926
 927 static int
 928 pipe_windows_write (struct serial *scb, const void *buf, size_t count)
 929 {
 930   struct pipe_state *ps = scb->state;
 931   HANDLE pipeline_in;
 932   DWORD written;
 933
 934   int pipeline_in_fd = fileno (ps->input);
 935   if (pipeline_in_fd < 0)
 936     return -1;
 937
 938   pipeline_in = (HANDLE) _get_osfhandle (pipeline_in_fd);
 939   if (pipeline_in == INVALID_HANDLE_VALUE)
 940     return -1;
 941
 942   if (! WriteFile (pipeline_in, buf, count, &written, NULL))
 943     return -1;
 944
 945   return written;
 946 }
 947
 948
 949 static void
 950 pipe_wait_handle (struct serial *scb, HANDLE *read, HANDLE *except)
 951 {
 952   struct pipe_state *ps = scb->state;
 953
 954   /* Have we allocated our events yet?  */
 955   if (ps->wait.read_event == INVALID_HANDLE_VALUE)
 956     /* Start the thread.  */
 957     create_select_thread (pipe_select_thread, scb, &ps->wait);
 958
 959   *read = ps->wait.read_event;
 960   *except = ps->wait.except_event;
 961
 962   /* Start from a blank state.  */
 963   ResetEvent (ps->wait.read_event);
 964   ResetEvent (ps->wait.except_event);
 965   ResetEvent (ps->wait.stop_select);
 966
 967   start_select_thread (&ps->wait);
 968 }
 969
 970 static void
 971 pipe_done_wait_handle (struct serial *scb)
 972 {
 973   struct pipe_state *ps = scb->state;
 974
 975   /* Have we allocated our events yet?  */
 976   if (ps->wait.read_event == INVALID_HANDLE_VALUE)
 977     return;
 978
 979   stop_select_thread (&ps->wait);
 980 }
 981
 982 static int
 983 pipe_avail (struct serial *scb, int fd)
 984 {
 985   HANDLE h = (HANDLE) _get_osfhandle (fd);
 986   DWORD numBytes;
 987   BOOL r = PeekNamedPipe (h, NULL, 0, NULL, &numBytes, NULL);
 988   if (r == FALSE)
 989     numBytes = 0;
 990   return numBytes;
 991 }
 992
 993 struct net_windows_state
 994 {
 995   struct ser_console_state base;
 996
 997   HANDLE sock_event;
 998 };
 999
1000 static DWORD WINAPI
1001 net_windows_select_thread (void *arg)
1002 {
1003   struct serial *scb = arg;
1004   struct net_windows_state *state;
1005   int event_index;
1006
1007   state = scb->state;
1008
1009   while (1)
1010     {
1011       HANDLE wait_events[2];
1012       WSANETWORKEVENTS events;
1013
1014       select_thread_wait (&state->base);
1015
1016       wait_events[0] = state->base.stop_select;
1017       wait_events[1] = state->sock_event;
1018
1019       event_index = WaitForMultipleObjects (2, wait_events, FALSE, INFINITE);
1020
1021       if (event_index == WAIT_OBJECT_0
1022           || WaitForSingleObject (state->base.stop_select, 0) == WAIT_OBJECT_0)
1023         /* We have been requested to stop.  */
1024         ;
1025       else if (event_index != WAIT_OBJECT_0 + 1)
1026         /* Some error has occured.  Assume that this is an error
1027            condition.  */
1028         SetEvent (state->base.except_event);
1029       else
1030         {
1031           /* Enumerate the internal network events, and reset the
1032              object that signalled us to catch the next event.  */
1033           WSAEnumNetworkEvents (scb->fd, state->sock_event, &events);
1034
1035           gdb_assert (events.lNetworkEvents & (FD_READ | FD_CLOSE));
1036
1037           if (events.lNetworkEvents & FD_READ)
1038             SetEvent (state->base.read_event);
1039
1040           if (events.lNetworkEvents & FD_CLOSE)
1041             SetEvent (state->base.except_event);
1042         }
1043
1044       SetEvent (state->base.have_stopped);
1045     }
1046 }
1047
1048 static void
1049 net_windows_wait_handle (struct serial *scb, HANDLE *read, HANDLE *except)
1050 {
1051   struct net_windows_state *state = scb->state;
1052
1053   /* Start from a clean slate.  */
1054   ResetEvent (state->base.read_event);
1055   ResetEvent (state->base.except_event);
1056   ResetEvent (state->base.stop_select);
1057
1058   *read = state->base.read_event;
1059   *except = state->base.except_event;
1060
1061   /* Check any pending events.  This both avoids starting the thread
1062      unnecessarily, and handles stray FD_READ events (see below).  */
1063   if (WaitForSingleObject (state->sock_event, 0) == WAIT_OBJECT_0)
1064     {
1065       WSANETWORKEVENTS events;
1066       int any = 0;
1067
1068       /* Enumerate the internal network events, and reset the object that
1069          signalled us to catch the next event.  */
1070       WSAEnumNetworkEvents (scb->fd, state->sock_event, &events);
1071
1072       /* You'd think that FD_READ or FD_CLOSE would be set here.  But,
1073          sometimes, neither is.  I suspect that the FD_READ is set and
1074          the corresponding event signalled while recv is running, and
1075          the FD_READ is then lowered when recv consumes all the data,
1076          but there's no way to un-signal the event.  This isn't a
1077          problem for the call in net_select_thread, since any new
1078          events after this point will not have been drained by recv.
1079          It just means that we can't have the obvious assert here.  */
1080
1081       /* If there is a read event, it might be still valid, or it might
1082          not be - it may have been signalled before we last called
1083          recv.  Double-check that there is data.  */
1084       if (events.lNetworkEvents & FD_READ)
1085         {
1086           unsigned long available;
1087
1088           if (ioctlsocket (scb->fd, FIONREAD, &available) == 0
1089               && available > 0)
1090             {
1091               SetEvent (state->base.read_event);
1092               any = 1;
1093             }
1094           else
1095             /* Oops, no data.  This call to recv will cause future
1096                data to retrigger the event, e.g. while we are
1097                in net_select_thread.  */
1098             recv (scb->fd, NULL, 0, 0);
1099         }
1100
1101       /* If there's a close event, then record it - it is obviously
1102          still valid, and it will not be resignalled.  */
1103       if (events.lNetworkEvents & FD_CLOSE)
1104         {
1105           SetEvent (state->base.except_event);
1106           any = 1;
1107         }
1108
1109       /* If we set either handle, there's no need to wake the thread.  */
1110       if (any)
1111         return;
1112     }
1113
1114   start_select_thread (&state->base);
1115 }
1116
1117 static void
1118 net_windows_done_wait_handle (struct serial *scb)
1119 {
1120   struct net_windows_state *state = scb->state;
1121
1122   stop_select_thread (&state->base);
1123 }
1124
1125 static int
1126 net_windows_open (struct serial *scb, const char *name)
1127 {
1128   struct net_windows_state *state;
1129   int ret;
1130   DWORD threadId;
1131
1132   ret = net_open (scb, name);
1133   if (ret != 0)
1134     return ret;
1135
1136   state = xmalloc (sizeof (struct net_windows_state));
1137   memset (state, 0, sizeof (struct net_windows_state));
1138   scb->state = state;
1139
1140   /* Associate an event with the socket.  */
1141   state->sock_event = CreateEvent (0, TRUE, FALSE, 0);
1142   WSAEventSelect (scb->fd, state->sock_event, FD_READ | FD_CLOSE);
1143
1144   /* Start the thread.  */
1145   create_select_thread (net_windows_select_thread, scb, &state->base);
1146
1147   return 0;
1148 }
1149
1150
1151 static void
1152 net_windows_close (struct serial *scb)
1153 {
1154   struct net_windows_state *state = scb->state;
1155
1156   destroy_select_thread (&state->base);
1157   CloseHandle (state->sock_event);
1158
1159   xfree (scb->state);
1160
1161   net_close (scb);
1162 }
1163
1164 void
1165 _initialize_ser_windows (void)
1166 {
1167   WSADATA wsa_data;
1168   struct serial_ops *ops;
1169
1170   /* First register the serial port driver.  */
1171
1172   ops = XMALLOC (struct serial_ops);
1173   memset (ops, 0, sizeof (struct serial_ops));
1174   ops->name = "hardwire";
1175   ops->next = 0;
1176   ops->open = ser_windows_open;
1177   ops->close = ser_windows_close;
1178
1179   ops->flush_output = ser_windows_flush_output;
1180   ops->flush_input = ser_windows_flush_input;
1181   ops->send_break = ser_windows_send_break;
1182
1183   /* These are only used for stdin; we do not need them for serial
1184      ports, so supply the standard dummies.  */
1185   ops->get_tty_state = ser_base_get_tty_state;
1186   ops->set_tty_state = ser_base_set_tty_state;
1187   ops->print_tty_state = ser_base_print_tty_state;
1188   ops->noflush_set_tty_state = ser_base_noflush_set_tty_state;
1189
1190   ops->go_raw = ser_windows_raw;
1191   ops->setbaudrate = ser_windows_setbaudrate;
1192   ops->setstopbits = ser_windows_setstopbits;
1193   ops->drain_output = ser_windows_drain_output;
1194   ops->readchar = ser_base_readchar;
1195   ops->write = ser_base_write;
1196   ops->async = ser_base_async;
1197   ops->read_prim = ser_windows_read_prim;
1198   ops->write_prim = ser_windows_write_prim;
1199   ops->wait_handle = ser_windows_wait_handle;
1200
1201   serial_add_interface (ops);
1202
1203   /* Next create the dummy serial driver used for terminals.  We only
1204      provide the TTY-related methods.  */
1205
1206   ops = XMALLOC (struct serial_ops);
1207   memset (ops, 0, sizeof (struct serial_ops));
1208
1209   ops->name = "terminal";
1210   ops->next = 0;
1211
1212   ops->close = ser_console_close;
1213   ops->get_tty_state = ser_console_get_tty_state;
1214   ops->set_tty_state = ser_base_set_tty_state;
1215   ops->print_tty_state = ser_base_print_tty_state;
1216   ops->noflush_set_tty_state = ser_base_noflush_set_tty_state;
1217   ops->drain_output = ser_base_drain_output;
1218   ops->wait_handle = ser_console_wait_handle;
1219   ops->done_wait_handle = ser_console_done_wait_handle;
1220
1221   serial_add_interface (ops);
1222
1223   /* The pipe interface.  */
1224
1225   ops = XMALLOC (struct serial_ops);
1226   memset (ops, 0, sizeof (struct serial_ops));
1227   ops->name = "pipe";
1228   ops->next = 0;
1229   ops->open = pipe_windows_open;
1230   ops->close = pipe_windows_close;
1231   ops->readchar = ser_base_readchar;
1232   ops->write = ser_base_write;
1233   ops->flush_output = ser_base_flush_output;
1234   ops->flush_input = ser_base_flush_input;
1235   ops->send_break = ser_base_send_break;
1236   ops->go_raw = ser_base_raw;
1237   ops->get_tty_state = ser_base_get_tty_state;
1238   ops->set_tty_state = ser_base_set_tty_state;
1239   ops->print_tty_state = ser_base_print_tty_state;
1240   ops->noflush_set_tty_state = ser_base_noflush_set_tty_state;
1241   ops->setbaudrate = ser_base_setbaudrate;
1242   ops->setstopbits = ser_base_setstopbits;
1243   ops->drain_output = ser_base_drain_output;
1244   ops->async = ser_base_async;
1245   ops->read_prim = pipe_windows_read;
1246   ops->write_prim = pipe_windows_write;
1247   ops->wait_handle = pipe_wait_handle;
1248   ops->done_wait_handle = pipe_done_wait_handle;
1249   ops->avail = pipe_avail;
1250
1251   serial_add_interface (ops);
1252
1253   /* If WinSock works, register the TCP/UDP socket driver.  */
1254
1255   if (WSAStartup (MAKEWORD (1, 0), &wsa_data) != 0)
1256     /* WinSock is unavailable.  */
1257     return;
1258
1259   ops = XMALLOC (struct serial_ops);
1260   memset (ops, 0, sizeof (struct serial_ops));
1261   ops->name = "tcp";
1262   ops->next = 0;
1263   ops->open = net_windows_open;
1264   ops->close = net_windows_close;
1265   ops->readchar = ser_base_readchar;
1266   ops->write = ser_base_write;
1267   ops->flush_output = ser_base_flush_output;
1268   ops->flush_input = ser_base_flush_input;
1269   ops->send_break = ser_tcp_send_break;
1270   ops->go_raw = ser_base_raw;
1271   ops->get_tty_state = ser_base_get_tty_state;
1272   ops->set_tty_state = ser_base_set_tty_state;
1273   ops->print_tty_state = ser_base_print_tty_state;
1274   ops->noflush_set_tty_state = ser_base_noflush_set_tty_state;
1275   ops->setbaudrate = ser_base_setbaudrate;
1276   ops->setstopbits = ser_base_setstopbits;
1277   ops->drain_output = ser_base_drain_output;
1278   ops->async = ser_base_async;
1279   ops->read_prim = net_read_prim;
1280   ops->write_prim = net_write_prim;
1281   ops->wait_handle = net_windows_wait_handle;
1282   ops->done_wait_handle = net_windows_done_wait_handle;
1283   serial_add_interface (ops);
1284 }