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 #include "wx/evtloop.h"
  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/thread.h"
  31 #include "wx/module.h"
  32 #include "wx/generic/private/timer.h"
  33 #include "wx/unix/private/epolldispatcher.h"
  34 #include "wx/private/selectdispatcher.h"
  35
  36 #define TRACE_EVENTS _T("events")
  37
  38 // ===========================================================================
  39 // wxEventLoop::PipeIOHandler implementation
  40 // ===========================================================================
  41
  42 // ----------------------------------------------------------------------------
  43 // initialization
  44 // ----------------------------------------------------------------------------
  45
  46 bool wxConsoleEventLoop::PipeIOHandler::Create()
  47 {
  48     if ( !m_pipe.Create() )
  49     {
  50         wxLogError(_("Failed to create wake up pipe used by event loop."));
  51         return false;
  52     }
  53
  54     const int fdRead = GetReadFd();
  55
  56     int flags = fcntl(fdRead, F_GETFL, 0);
  57     if ( flags == -1 || fcntl(fdRead, F_SETFL, flags | O_NONBLOCK) == -1 )
  58     {
  59         wxLogSysError(_("Failed to switch wake up pipe to non-blocking mode"));
  60         return false;
  61     }
  62
  63     wxLogTrace(TRACE_EVENTS, wxT("Wake up pipe (%d, %d) created"),
  64                fdRead, m_pipe[wxPipe::Write]);
  65
  66     return true;
  67 }
  68
  69 // ----------------------------------------------------------------------------
  70 // wakeup handling
  71 // ----------------------------------------------------------------------------
  72
  73 void wxConsoleEventLoop::PipeIOHandler::WakeUp()
  74 {
  75     if ( write(m_pipe[wxPipe::Write], "s", 1) != 1 )
  76     {
  77         // don't use wxLog here, we can be in another thread and this could
  78         // result in dead locks
  79         perror("write(wake up pipe)");
  80     }
  81 }
  82
  83 void wxConsoleEventLoop::PipeIOHandler::OnReadWaiting()
  84 {
  85     // got wakeup from child thread: read all data available in pipe just to
  86     // make it empty (evevn though we write one byte at a time from WakeUp(),
  87     // it could have been called several times)
  88     char buf[4];
  89     for ( ;; )
  90     {
  91         const int size = read(GetReadFd(), buf, WXSIZEOF(buf));
  92
  93         if ( size == 0 || (size == -1 && errno == EAGAIN) )
  94         {
  95             // nothing left in the pipe (EAGAIN is expected for an FD with
  96             // O_NONBLOCK)
  97             break;
  98         }
  99
 100         if ( size == -1 )
 101         {
 102             wxLogSysError(_("Failed to read from wake-up pipe"));
 103
 104             break;
 105         }
 106     }
 107
 108     wxTheApp->ProcessPendingEvents();
 109 }
 110
 111 // ===========================================================================
 112 // wxEventLoop implementation
 113 // ===========================================================================
 114
 115 //-----------------------------------------------------------------------------
 116 // initialization
 117 //-----------------------------------------------------------------------------
 118
 119 wxConsoleEventLoop::wxConsoleEventLoop()
 120 {
 121     if ( !m_wakeupPipe.Create() )
 122     {
 123         m_dispatcher = NULL;
 124         return;
 125     }
 126
 127 #ifdef HAVE_SYS_EPOLL_H
 128     m_dispatcher = wxEpollDispatcher::Get();
 129     if ( !m_dispatcher )
 130 #endif // HAVE_SYS_EPOLL_H
 131     {
 132         m_dispatcher = wxSelectDispatcher::Get();
 133     }
 134
 135     wxCHECK_RET( m_dispatcher, _T("failed to create IO dispatcher") );
 136
 137     m_dispatcher->RegisterFD
 138                   (
 139                     m_wakeupPipe.GetReadFd(),
 140                     &m_wakeupPipe,
 141                     wxFDIO_INPUT
 142                   );
 143 };
 144
 145 //-----------------------------------------------------------------------------
 146 // events dispatch and loop handling
 147 //-----------------------------------------------------------------------------
 148
 149 bool wxConsoleEventLoop::Pending() const
 150 {
 151     return wxTheApp->HasPendingEvents();
 152 }
 153
 154 bool wxConsoleEventLoop::Dispatch()
 155 {
 156     wxTheApp->ProcessPendingEvents();
 157     return true;
 158 }
 159
 160 void wxConsoleEventLoop::WakeUp()
 161 {
 162     m_wakeupPipe.WakeUp();
 163 }
 164
 165 void wxConsoleEventLoop::OnNextIteration()
 166 {
 167     // calculate the timeout until the next timer expiration
 168     int timeout;
 169
 170 #if wxUSE_TIMER
 171     wxUsecClock_t nextTimer;
 172     if ( wxTimerScheduler::Get().GetNext(&nextTimer) )
 173     {
 174         // timeout is in ms
 175         timeout = (nextTimer / 1000).ToLong();
 176     }
 177     else // no timers, we can block forever
 178 #endif // wxUSE_TIMER
 179     {
 180         timeout = wxFDIODispatcher::TIMEOUT_INFINITE;
 181     }
 182
 183     m_dispatcher->RunLoop(timeout);
 184
 185 #if wxUSE_TIMER
 186     wxTimerScheduler::Get().NotifyExpired();
 187 #endif
 188
 189     // call the signal handlers for any signals we caught recently
 190     wxTheApp->CheckSignal();
 191 }
 192