implement event loop for console applications (heavily modified patch 1715735)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@46029 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/unix/evtloopunix.cpp

@@ -0,0 +1,192 @@
+/////////////////////////////////////////////////////////////////////////////
+// Name:        src/unix/evtloopunix.cpp
+// Purpose:     wxEventLoop implementation
+// Author:      Lukasz Michalski (lm@zork.pl)
+// Created:     2007-05-07
+// RCS-ID:      $Id$
+// Copyright:   (c) 2006 Zork Lukasz Michalski
+// Licence:     wxWindows licence
+/////////////////////////////////////////////////////////////////////////////
+
+// ===========================================================================
+// declarations
+// ===========================================================================
+
+// ---------------------------------------------------------------------------
+// headers
+// ---------------------------------------------------------------------------
+
+// For compilers that support precompilation, includes "wx.h".
+#include "wx/wxprec.h"
+
+#include "wx/evtloop.h"
+
+#ifndef WX_PRECOMP
+    #include "wx/app.h"
+    #include "wx/log.h"
+#endif
+
+#include <errno.h>
+#include "wx/thread.h"
+#include "wx/module.h"
+#include "wx/generic/private/timer.h"
+#include "wx/unix/private/epolldispatcher.h"
+#include "wx/private/selectdispatcher.h"
+
+#define TRACE_EVENTS _T("events")
+
+// ===========================================================================
+// wxEventLoop::PipeIOHandler implementation
+// ===========================================================================
+
+// ----------------------------------------------------------------------------
+// initialization
+// ----------------------------------------------------------------------------
+
+bool wxConsoleEventLoop::PipeIOHandler::Create()
+{
+    if ( !m_pipe.Create() )
+    {
+        wxLogError(_("Failed to create wake up pipe used by event loop."));
+        return false;
+    }
+
+    const int fdRead = GetReadFd();
+
+    int flags = fcntl(fdRead, F_GETFL, 0);
+    if ( flags == -1 || fcntl(fdRead, F_SETFL, flags | O_NONBLOCK) == -1 )
+    {
+        wxLogSysError(_("Failed to switch wake up pipe to non-blocking mode"));
+        return false;
+    }
+
+    wxLogTrace(TRACE_EVENTS, wxT("Wake up pipe (%d, %d) created"),
+               fdRead, m_pipe[wxPipe::Write]);
+
+    return true;
+}
+
+// ----------------------------------------------------------------------------
+// wakeup handling
+// ----------------------------------------------------------------------------
+
+void wxConsoleEventLoop::PipeIOHandler::WakeUp()
+{
+    if ( write(m_pipe[wxPipe::Write], "s", 1) != 1 )
+    {
+        // don't use wxLog here, we can be in another thread and this could
+        // result in dead locks
+        perror("write(wake up pipe)");
+    }
+}
+
+void wxConsoleEventLoop::PipeIOHandler::OnReadWaiting()
+{
+    // got wakeup from child thread: read all data available in pipe just to
+    // make it empty (evevn though we write one byte at a time from WakeUp(),
+    // it could have been called several times)
+    char buf[4];
+    for ( ;; )
+    {
+        const int size = read(GetReadFd(), buf, WXSIZEOF(buf));
+
+        if ( size == 0 || (size == -1 && errno == EAGAIN) )
+        {
+            // nothing left in the pipe (EAGAIN is expected for an FD with
+            // O_NONBLOCK)
+            break;
+        }
+
+        if ( size == -1 )
+        {
+            wxLogSysError(_("Failed to read from wake-up pipe"));
+
+            break;
+        }
+    }
+
+    wxTheApp->ProcessPendingEvents();
+}
+
+// ===========================================================================
+// wxEventLoop implementation
+// ===========================================================================
+
+//-----------------------------------------------------------------------------
+// initialization
+//-----------------------------------------------------------------------------
+
+wxConsoleEventLoop::wxConsoleEventLoop()
+{
+    if ( !m_wakeupPipe.Create() )
+    {
+        m_dispatcher = NULL;
+        return;
+    }
+
+#ifdef HAVE_SYS_EPOLL_H
+    m_dispatcher = wxEpollDispatcher::Get();
+    if ( !m_dispatcher )
+#endif // HAVE_SYS_EPOLL_H
+    {
+        m_dispatcher = wxSelectDispatcher::Get();
+    }
+
+    wxCHECK_RET( m_dispatcher, _T("failed to create IO dispatcher") );
+
+    m_dispatcher->RegisterFD
+                  (
+                    m_wakeupPipe.GetReadFd(),
+                    &m_wakeupPipe,
+                    wxFDIO_INPUT
+                  );
+};
+
+//-----------------------------------------------------------------------------
+// events dispatch and loop handling
+//-----------------------------------------------------------------------------
+
+bool wxConsoleEventLoop::Pending() const
+{
+    return wxTheApp->HasPendingEvents();
+}
+
+bool wxConsoleEventLoop::Dispatch()
+{
+    wxTheApp->ProcessPendingEvents();
+    return true;
+}
+
+void wxConsoleEventLoop::WakeUp()
+{
+    m_wakeupPipe.WakeUp();
+}
+
+void wxConsoleEventLoop::OnNextIteration()
+{
+    // calculate the timeout until the next timer expiration
+    int timeout;
+
+#if wxUSE_TIMER
+    wxUsecClock_t nextTimer;
+    if ( wxTimerScheduler::Get().GetNext(&nextTimer) )
+    {
+        // timeout is in ms
+        timeout = (nextTimer / 1000).ToLong();
+    }
+    else // no timers, we can block forever
+#endif // wxUSE_TIMER
+    {
+        timeout = wxFDIODispatcher::TIMEOUT_INFINITE;
+    }
+
+    m_dispatcher->RunLoop(timeout);
+
+#if wxUSE_TIMER
+    wxTimerScheduler::Get().NotifyExpired();
+#endif
+
+    // call the signal handlers for any signals we caught recently
+    wxTheApp->CheckSignal();
+}
+