winsup/cygwin/cygwait.cc

   1 /* cygwait.h
   2
   3    Copyright 2011, 2012 Red Hat, Inc.
   4
   5    This file is part of Cygwin.
   6
   7    This software is a copyrighted work licensed under the terms of the
   8    Cygwin license.  Please consult the file "CYGWIN_LICENSE" for
   9    details.  */
  10
  11 #include "winsup.h"
  12 #include "sigproc.h"
  13 #include "cygwait.h"
  14 #include "ntdll.h"
  15
  16 #define is_cw_cancel            (mask & cw_cancel)
  17 #define is_cw_cancel_self       (mask & cw_cancel_self)
  18 #define is_cw_sig               (mask & cw_sig)
  19 #define is_cw_sig_eintr         (mask & cw_sig_eintr)
  20 #define is_cw_sig_return        (mask & cw_sig_return)
  21
  22 #define is_cw_sig_handle        (mask & (is_cw_sig | is_cw_sig_eintr))
  23
  24 DWORD
  25 cancelable_wait (HANDLE object, PLARGE_INTEGER timeout, unsigned mask)
  26 {
  27   DWORD res;
  28   DWORD num = 0;
  29   HANDLE wait_objects[4];
  30   pthread_t thread = pthread::self ();
  31
  32   /* Do not change the wait order.
  33      The object must have higher priority than the cancel event,
  34      because WaitForMultipleObjects will return the smallest index
  35      if both objects are signaled. */
  36   if (object)
  37     wait_objects[num++] = object;
  38
  39   DWORD sig_n;
  40   if (!is_cw_sig_handle)
  41     sig_n = WAIT_TIMEOUT + 1;
  42   else
  43     {
  44       sig_n = WAIT_OBJECT_0 + num++;
  45       wait_objects[sig_n] = signal_arrived;
  46     }
  47
  48   DWORD cancel_n;
  49   if (!is_cw_cancel || !pthread::is_good_object (&thread) ||
  50       thread->cancelstate == PTHREAD_CANCEL_DISABLE)
  51     cancel_n = WAIT_TIMEOUT + 1;
  52   else
  53     {
  54       cancel_n = WAIT_OBJECT_0 + num++;
  55       wait_objects[cancel_n] = thread->cancel_event;
  56     }
  57
  58   DWORD timeout_n;
  59   if (!timeout)
  60     timeout_n = WAIT_TIMEOUT + 1;
  61   else
  62     {
  63       timeout_n = WAIT_OBJECT_0 + num++;
  64       if (!_my_tls.locals.cw_timer)
  65         NtCreateTimer (&_my_tls.locals.cw_timer, TIMER_ALL_ACCESS, NULL,
  66                        NotificationTimer);
  67       NtSetTimer (_my_tls.locals.cw_timer, timeout, NULL, NULL, FALSE, 0, NULL);
  68       wait_objects[timeout_n] = _my_tls.locals.cw_timer;
  69     }
  70
  71   while (1)
  72     {
  73       res = WaitForMultipleObjects (num, wait_objects, FALSE, INFINITE);
  74       if (res == cancel_n)
  75         {
  76           if (is_cw_cancel_self)
  77             pthread::static_cancel_self ();
  78           res = WAIT_CANCELED;
  79         }
  80       else if (res == timeout_n)
  81         res = WAIT_TIMEOUT;
  82       else if (res != sig_n)
  83         /* all set */;
  84       else if (is_cw_sig_eintr)
  85         res = WAIT_SIGNALED;
  86       else if (_my_tls.call_signal_handler () || &_my_tls != _main_tls)
  87         continue;
  88       break;
  89     }
  90
  91   if (timeout)
  92     {
  93       TIMER_BASIC_INFORMATION tbi;
  94
  95       NtQueryTimer (_my_tls.locals.cw_timer, TimerBasicInformation, &tbi,
  96                     sizeof tbi, NULL);
  97       /* if timer expired, TimeRemaining is negative and represents the
  98           system uptime when signalled */
  99       if (timeout->QuadPart < 0LL)
 100         timeout->QuadPart = tbi.SignalState ? 0LL : tbi.TimeRemaining.QuadPart;
 101       NtCancelTimer (_my_tls.locals.cw_timer, NULL);
 102     }
 103
 104   return res;
 105 }