src/unix/evtloopunix.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        src/unix/evtloopunix.cpp
   3 // Purpose:     wxEventLoop implementation
   4 // Author:      Lukasz Michalski (lm@zork.pl)
   5 // Created:     2007-05-07
   6 // RCS-ID:      $Id$
   7 // Copyright:   (c) 2006 Zork Lukasz Michalski
   8 // Licence:     wxWindows licence
   9 /////////////////////////////////////////////////////////////////////////////
  10
  11 // ===========================================================================
  12 // declarations
  13 // ===========================================================================
  14
  15 // ---------------------------------------------------------------------------
  16 // headers
  17 // ---------------------------------------------------------------------------
  18
  19 // For compilers that support precompilation, includes "wx.h".
  20 #include "wx/wxprec.h"
  21
  22 #if wxUSE_CONSOLE_EVENTLOOP
  23
  24 #ifndef WX_PRECOMP
  25     #include "wx/app.h"
  26     #include "wx/log.h"
  27 #endif
  28
  29 #include <errno.h>
  30 #include "wx/apptrait.h"
  31 #include "wx/evtloop.h"
  32 #include "wx/thread.h"
  33 #include "wx/module.h"
  34 #include "wx/unix/private/timer.h"
  35 #include "wx/unix/private/epolldispatcher.h"
  36 #include "wx/private/selectdispatcher.h"
  37
  38 #define TRACE_EVENTS _T("events")
  39
  40 // ===========================================================================
  41 // wxEventLoop::PipeIOHandler implementation
  42 // ===========================================================================
  43
  44 // ----------------------------------------------------------------------------
  45 // initialization
  46 // ----------------------------------------------------------------------------
  47
  48 bool wxConsoleEventLoop::PipeIOHandler::Create()
  49 {
  50     if ( !m_pipe.Create() )
  51     {
  52         wxLogError(_("Failed to create wake up pipe used by event loop."));
  53         return false;
  54     }
  55
  56     const int fdRead = GetReadFd();
  57
  58     int flags = fcntl(fdRead, F_GETFL, 0);
  59     if ( flags == -1 || fcntl(fdRead, F_SETFL, flags | O_NONBLOCK) == -1 )
  60     {
  61         wxLogSysError(_("Failed to switch wake up pipe to non-blocking mode"));
  62         return false;
  63     }
  64
  65     wxLogTrace(TRACE_EVENTS, wxT("Wake up pipe (%d, %d) created"),
  66                fdRead, m_pipe[wxPipe::Write]);
  67
  68     return true;
  69 }
  70
  71 // ----------------------------------------------------------------------------
  72 // wakeup handling
  73 // ----------------------------------------------------------------------------
  74
  75 void wxConsoleEventLoop::PipeIOHandler::WakeUp()
  76 {
  77     if ( write(m_pipe[wxPipe::Write], "s", 1) != 1 )
  78     {
  79         // don't use wxLog here, we can be in another thread and this could
  80         // result in dead locks
  81         perror("write(wake up pipe)");
  82     }
  83 }
  84
  85 void wxConsoleEventLoop::PipeIOHandler::OnReadWaiting()
  86 {
  87     // got wakeup from child thread: read all data available in pipe just to
  88     // make it empty (evevn though we write one byte at a time from WakeUp(),
  89     // it could have been called several times)
  90     char buf[4];
  91     for ( ;; )
  92     {
  93         const int size = read(GetReadFd(), buf, WXSIZEOF(buf));
  94
  95         if ( size == 0 || (size == -1 && errno == EAGAIN) )
  96         {
  97             // nothing left in the pipe (EAGAIN is expected for an FD with
  98             // O_NONBLOCK)
  99             break;
 100         }
 101
 102         if ( size == -1 )
 103         {
 104             wxLogSysError(_("Failed to read from wake-up pipe"));
 105
 106             break;
 107         }
 108     }
 109
 110     wxTheApp->ProcessPendingEvents();
 111 }
 112
 113 // ===========================================================================
 114 // wxEventLoop implementation
 115 // ===========================================================================
 116
 117 //-----------------------------------------------------------------------------
 118 // initialization
 119 //-----------------------------------------------------------------------------
 120
 121 wxConsoleEventLoop::wxConsoleEventLoop()
 122 {
 123     if ( !m_wakeupPipe.Create() )
 124     {
 125         m_dispatcher = NULL;
 126         return;
 127     }
 128
 129     m_dispatcher = wxFDIODispatcher::Get();
 130     if ( !m_dispatcher )
 131         return;
 132
 133     m_dispatcher->RegisterFD
 134                   (
 135                     m_wakeupPipe.GetReadFd(),
 136                     &m_wakeupPipe,
 137                     wxFDIO_INPUT
 138                   );
 139 }
 140
 141 //-----------------------------------------------------------------------------
 142 // events dispatch and loop handling
 143 //-----------------------------------------------------------------------------
 144
 145 bool wxConsoleEventLoop::Pending() const
 146 {
 147     return wxTheApp->HasPendingEvents();
 148 }
 149
 150 bool wxConsoleEventLoop::Dispatch()
 151 {
 152     // calculate the timeout until the next timer expiration
 153     int timeout;
 154
 155 #if wxUSE_TIMER
 156     wxUsecClock_t nextTimer;
 157     if ( wxTimerScheduler::Get().GetNext(&nextTimer) )
 158     {
 159         // timeout is in ms
 160         timeout = (nextTimer / 1000).ToLong();
 161     }
 162     else // no timers, we can block forever
 163 #endif // wxUSE_TIMER
 164     {
 165         timeout = wxFDIODispatcher::TIMEOUT_INFINITE;
 166     }
 167
 168     m_dispatcher->Dispatch(timeout);
 169
 170 #if wxUSE_TIMER
 171     wxTimerScheduler::Get().NotifyExpired();
 172 #endif
 173
 174     wxTheApp->ProcessPendingEvents();
 175     return true;
 176 }
 177
 178 void wxConsoleEventLoop::WakeUp()
 179 {
 180     m_wakeupPipe.WakeUp();
 181 }
 182
 183 void wxConsoleEventLoop::OnNextIteration()
 184 {
 185     // call the signal handlers for any signals we caught recently
 186     wxTheApp->CheckSignal();
 187 }
 188
 189
 190 wxEventLoopBase *wxConsoleAppTraits::CreateEventLoop()
 191 {
 192     return new wxEventLoop();
 193 }
 194
 195 #endif // wxUSE_CONSOLE_EVENTLOOP