winsup/cygwin/cygwait.cc

   1 /* cygwait.h
   2
   3    This file is part of Cygwin.
   4
   5    This software is a copyrighted work licensed under the terms of the
   6    Cygwin license.  Please consult the file "CYGWIN_LICENSE" for
   7    details.  */
   8
   9 #include "winsup.h"
  10 #include "sigproc.h"
  11 #include "cygwait.h"
  12 #include "ntdll.h"
  13
  14 #define is_cw_cancel            (mask & cw_cancel)
  15 #define is_cw_cancel_self       (mask & cw_cancel_self)
  16 #define is_cw_sig               (mask & cw_sig)
  17 #define is_cw_sig_eintr         (mask & cw_sig_eintr)
  18 #define is_cw_sig_cont          (mask & cw_sig_cont)
  19 #define is_cw_sig_restart       (mask & cw_sig_restart)
  20
  21 #define is_cw_sig_handle        (mask & (cw_sig | cw_sig_eintr \
  22                                          | cw_sig_cont | cw_sig_restart))
  23
  24 LARGE_INTEGER cw_nowait_storage;
  25
  26 DWORD
  27 cygwait (HANDLE object, PLARGE_INTEGER timeout, unsigned mask)
  28 {
  29   DWORD res;
  30   DWORD num = 0;
  31   HANDLE wait_objects[4];
  32   pthread_t thread = pthread::self ();
  33
  34   /* Do not change the wait order.
  35      The object must have higher priority than the cancel event,
  36      because WaitForMultipleObjects will return the smallest index
  37      if both objects are signaled. */
  38   if (object)
  39     wait_objects[num++] = object;
  40
  41   wait_signal_arrived thread_waiting (is_cw_sig_handle, wait_objects[num]);
  42   debug_only_printf ("object %p, thread waiting %d, signal_arrived %p",
  43                      object, (int) thread_waiting, _my_tls.signal_arrived);
  44   DWORD sig_n;
  45   if (!thread_waiting)
  46     sig_n = WAIT_TIMEOUT + 1;
  47   else
  48     sig_n = WAIT_OBJECT_0 + num++;
  49
  50   DWORD cancel_n;
  51   if (!is_cw_cancel || !pthread::is_good_object (&thread) ||
  52       thread->cancelstate == PTHREAD_CANCEL_DISABLE)
  53     cancel_n = WAIT_TIMEOUT + 1;
  54   else
  55     {
  56       cancel_n = WAIT_OBJECT_0 + num++;
  57       wait_objects[cancel_n] = thread->cancel_event;
  58     }
  59
  60   DWORD timeout_n;
  61   if (!timeout)
  62     timeout_n = WAIT_TIMEOUT + 1;
  63   else
  64     {
  65       timeout_n = WAIT_OBJECT_0 + num++;
  66       if (!_my_tls.locals.cw_timer)
  67         NtCreateTimer (&_my_tls.locals.cw_timer, TIMER_ALL_ACCESS, NULL,
  68                        NotificationTimer);
  69       NtSetTimer (_my_tls.locals.cw_timer, timeout, NULL, NULL, FALSE, 0, NULL);
  70       wait_objects[timeout_n] = _my_tls.locals.cw_timer;
  71     }
  72
  73   while (1)
  74     {
  75       res = WaitForMultipleObjects (num, wait_objects, FALSE, INFINITE);
  76       debug_only_printf ("res %d", res);
  77       if (res == cancel_n)
  78         res = WAIT_CANCELED;
  79       else if (res == timeout_n)
  80         res = WAIT_TIMEOUT;
  81       else if (res != sig_n)
  82         /* all set */;
  83       else
  84         {
  85           int sig = _my_tls.current_sig;
  86           if (is_cw_sig_cont && sig == SIGCONT)
  87             _my_tls.current_sig = 0;
  88           if (!sig)
  89             continue;
  90           if (is_cw_sig_eintr || (is_cw_sig_cont && sig == SIGCONT))
  91             ;
  92           else if (_my_tls.call_signal_handler () || is_cw_sig_restart)
  93             continue;
  94           res = WAIT_SIGNALED;  /* caller will deal with signals */
  95         }
  96       break;
  97     }
  98
  99   if (timeout)
 100     {
 101       TIMER_BASIC_INFORMATION tbi;
 102
 103       NtQueryTimer (_my_tls.locals.cw_timer, TimerBasicInformation, &tbi,
 104                     sizeof tbi, NULL);
 105       /* if timer expired, TimeRemaining is negative and represents the
 106           system uptime when signalled */
 107       if (timeout->QuadPart < 0LL) {
 108         timeout->QuadPart = tbi.SignalState || tbi.TimeRemaining.QuadPart < 0LL
 109                             ? 0LL : tbi.TimeRemaining.QuadPart;
 110       }
 111       NtCancelTimer (_my_tls.locals.cw_timer, NULL);
 112     }
 113
 114   if (res == WAIT_CANCELED && is_cw_cancel_self)
 115     pthread::static_cancel_self ();
 116
 117   return res;
 118 }