preserve type when loaded image is rescaled, #11543

[wxWidgets.git] / src / unix / epolldispatcher.cpp

diff --git a/src/unix/epolldispatcher.cpp b/src/unix/epolldispatcher.cpp
index 8df776cba17e6ed1030414924947d495983554ab..503920d7ceeb0049d8eae650eec9188eeb1ff898 100644 (file)
--- a/src/unix/epolldispatcher.cpp
+++ b/src/unix/epolldispatcher.cpp
@@ -19,10 +19,11 @@
 // for compilers that support precompilation, includes "wx.h".
 #include "wx/wxprec.h"
 
-#ifdef wxUSE_EPOLL_DISPATCHER
+#if wxUSE_EPOLL_DISPATCHER
 
 #include "wx/unix/private/epolldispatcher.h"
 #include "wx/unix/private.h"
+#include "wx/stopwatch.h"
 
 #ifndef WX_PRECOMP
     #include "wx/log.h"
@@ -31,6 +32,7 @@
 
 #include <sys/epoll.h>
 #include <errno.h>
+#include <unistd.h>
 
 #define wxEpollDispatcher_Trace wxT("epolldispatcher")
 
@@ -42,27 +44,29 @@
 // debugging messages about it)
 static uint32_t GetEpollMask(int flags, int fd)
 {
+    wxUnusedVar(fd); // unused if wxLogTrace() disabled
+
     uint32_t ep = 0;
 
     if ( flags & wxFDIO_INPUT )
     {
         ep |= EPOLLIN;
         wxLogTrace(wxEpollDispatcher_Trace,
-                   _T("Registered fd %d for input events"), fd);
+                   wxT("Registered fd %d for input events"), fd);
     }
 
     if ( flags & wxFDIO_OUTPUT )
     {
         ep |= EPOLLOUT;
         wxLogTrace(wxEpollDispatcher_Trace,
-                   _T("Registered fd %d for output events"), fd);
+                   wxT("Registered fd %d for output events"), fd);
     }
 
     if ( flags & wxFDIO_EXCEPTION )
     {
         ep |= EPOLLERR | EPOLLHUP;
         wxLogTrace(wxEpollDispatcher_Trace,
-                   _T("Registered fd %d for exceptional events"), fd);
+                   wxT("Registered fd %d for exceptional events"), fd);
     }
 
     return ep;
@@ -81,13 +85,14 @@ wxEpollDispatcher *wxEpollDispatcher::Create()
         wxLogSysError(_("Failed to create epoll descriptor"));
         return NULL;
     }
-
+    wxLogTrace(wxEpollDispatcher_Trace,
+                   wxT("Epoll fd %d created"), epollDescriptor);
     return new wxEpollDispatcher(epollDescriptor);
 }
 
 wxEpollDispatcher::wxEpollDispatcher(int epollDescriptor)
 {
-    wxASSERT_MSG( epollDescriptor != -1, _T("invalid descriptor") );
+    wxASSERT_MSG( epollDescriptor != -1, wxT("invalid descriptor") );
 
     m_epollDescriptor = epollDescriptor;
 }
@@ -114,6 +119,8 @@ bool wxEpollDispatcher::RegisterFD(int fd, wxFDIOHandler* handler, int flags)
 
         return false;
     }
+    wxLogTrace(wxEpollDispatcher_Trace,
+               wxT("Added fd %d (handler %p) to epoll %d"), fd, handler, m_epollDescriptor);
 
     return true;
 }
@@ -133,6 +140,8 @@ bool wxEpollDispatcher::ModifyFD(int fd, wxFDIOHandler* handler, int flags)
         return false;
     }
 
+    wxLogTrace(wxEpollDispatcher_Trace,
+                wxT("Modified fd %d (handler: %p) on epoll %d"), fd, handler, m_epollDescriptor);
     return true;
 }
 
@@ -147,48 +156,93 @@ bool wxEpollDispatcher::UnregisterFD(int fd)
         wxLogSysError(_("Failed to unregister descriptor %d from epoll descriptor %d"),
                       fd, m_epollDescriptor);
     }
-
+    wxLogTrace(wxEpollDispatcher_Trace,
+                wxT("removed fd %d from %d"), fd, m_epollDescriptor);
     return true;
 }
 
-void wxEpollDispatcher::Dispatch(int timeout)
+int
+wxEpollDispatcher::DoPoll(epoll_event *events, int numEvents, int timeout) const
+{
+    // the code below relies on TIMEOUT_INFINITE being -1 so that we can pass
+    // timeout value directly to epoll_wait() which interprets -1 as meaning to
+    // wait forever and would need to be changed if the value of
+    // TIMEOUT_INFINITE ever changes
+    wxCOMPILE_TIME_ASSERT( TIMEOUT_INFINITE == -1, UpdateThisCode );
+
+    wxMilliClock_t timeEnd;
+    if ( timeout > 0 )
+        timeEnd = wxGetLocalTimeMillis();
+
+    int rc;
+    for ( ;; )
+    {
+        rc = epoll_wait(m_epollDescriptor, events, numEvents, timeout);
+        if ( rc != -1 || errno != EINTR )
+            break;
+
+        // we got interrupted, update the timeout and restart
+        if ( timeout > 0 )
+        {
+            timeout = wxMilliClockToLong(timeEnd - wxGetLocalTimeMillis());
+            if ( timeout < 0 )
+                return 0;
+        }
+    }
+
+    return rc;
+}
+
+bool wxEpollDispatcher::HasPending() const
+{
+    epoll_event event;
+
+    // NB: it's not really clear if epoll_wait() can return a number greater
+    //     than the number of events passed to it but just in case it can, use
+    //     >= instead of == here, see #10397
+    return DoPoll(&event, 1, 0) >= 1;
+}
+
+int wxEpollDispatcher::Dispatch(int timeout)
 {
     epoll_event events[16];
 
-    const int e_num = epoll_wait
-                      (
-                        m_epollDescriptor,
-                        events,
-                        WXSIZEOF(events),
-                        timeout == TIMEOUT_INFINITE ? -1 : timeout
-                      );
+    const int rc = DoPoll(events, WXSIZEOF(events), timeout);
 
-    if ( e_num == -1 )
+    if ( rc == -1 )
     {
-        if ( errno != EINTR )
-        {
-            wxLogSysError(_("Waiting for IO on epoll descriptor %d failed"),
-                          m_epollDescriptor);
-            return;
-        }
+        wxLogSysError(_("Waiting for IO on epoll descriptor %d failed"),
+                      m_epollDescriptor);
+        return -1;
     }
 
-    for ( epoll_event *p = events; p < events + e_num; p++ )
+    int numEvents = 0;
+    for ( epoll_event *p = events; p < events + rc; p++ )
     {
         wxFDIOHandler * const handler = (wxFDIOHandler *)(p->data.ptr);
         if ( !handler )
         {
-            wxFAIL_MSG( _T("NULL handler in epoll_event?") );
+            wxFAIL_MSG( wxT("NULL handler in epoll_event?") );
             continue;
         }
 
-        if ( p->events & EPOLLIN )
+        // note that for compatibility with wxSelectDispatcher we call
+        // OnReadWaiting() on EPOLLHUP as this is what epoll_wait() returns
+        // when the write end of a pipe is closed while with select() the
+        // remaining pipe end becomes ready for reading when this happens
+        if ( p->events & (EPOLLIN | EPOLLHUP) )
             handler->OnReadWaiting();
         else if ( p->events & EPOLLOUT )
             handler->OnWriteWaiting();
-        else if ( p->events & (EPOLLERR | EPOLLHUP) )
+        else if ( p->events & EPOLLERR )
             handler->OnExceptionWaiting();
+        else
+            continue;
+
+        numEvents++;
     }
+
+    return numEvents;
 }
 
 #endif // wxUSE_EPOLL_DISPATCHER