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      1 /* gpoll.h - poll(2) support
      2  * Copyright (C) 2008 Red Hat, Inc.
      3  *
      4  * This library is free software; you can redistribute it and/or
      5  * modify it under the terms of the GNU Library General Public
      6  * License as published by the Free Software Foundation; either
      7  * version 2 of the License, or (at your option) any later version.
      8  *
      9  * This library is distributed in the hope that it will be useful,
     10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
     11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU
     12  * Library General Public License for more details.
     13  *
     14  * You should have received a copy of the GNU Library General Public
     15  * License along with this library; if not, write to the
     16  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
     17  * Boston, MA 02111-1307, USA.
     18  */
     19 
     20 #if !defined (__GLIB_H_INSIDE__) && !defined (__G_MAIN_H__) && !defined (GLIB_COMPILATION)
     21 #error "Only <glib.h> can be included directly."
     22 #endif
     23 
     24 #ifndef __G_POLL_H__
     25 #define __G_POLL_H__
     26 
     27 #include <glib/gtypes.h>
     28 
     29 G_BEGIN_DECLS
     30 
     31 /* Any definitions using GPollFD or GPollFunc are primarily
     32  * for Unix and not guaranteed to be the compatible on all
     33  * operating systems on which GLib runs. Right now, the
     34  * GLib does use these functions on Win32 as well, but interprets
     35  * them in a fairly different way than on Unix. If you use
     36  * these definitions, you are should be prepared to recode
     37  * for different operating systems.
     38  *
     39  * Note that on systems with a working poll(2), that function is used
     40  * in place of g_poll(). Thus g_poll() must have the same signature as
     41  * poll(), meaning GPollFD must have the same layout as struct pollfd.
     42  *
     43  *
     44  * On Win32, the fd in a GPollFD should be Win32 HANDLE (*not* a file
     45  * descriptor as provided by the C runtime) that can be used by
     46  * MsgWaitForMultipleObjects. This does *not* include file handles
     47  * from CreateFile, SOCKETs, nor pipe handles. (But you can use
     48  * WSAEventSelect to signal events when a SOCKET is readable).
     49  *
     50  * On Win32, fd can also be the special value G_WIN32_MSG_HANDLE to
     51  * indicate polling for messages.
     52  *
     53  * But note that G_WIN32_MSG_HANDLE GPollFDs should not be used by GDK
     54  * (GTK) programs, as GDK itself wants to read messages and convert them
     55  * to GDK events.
     56  *
     57  * So, unless you really know what you are doing, it's best not to try
     58  * to use the main loop polling stuff for your own needs on
     59  * Windows.
     60  */
     61 typedef struct _GPollFD GPollFD;
     62 typedef gint	(*GPollFunc)	(GPollFD *ufds,
     63 				 guint	  nfsd,
     64 				 gint     timeout_);
     65 
     66 struct _GPollFD
     67 {
     68 #if defined (G_OS_WIN32) && GLIB_SIZEOF_VOID_P == 8
     69   gint64	fd;
     70 #else
     71   gint		fd;
     72 #endif
     73   gushort 	events;
     74   gushort 	revents;
     75 };
     76 
     77 #ifdef G_OS_WIN32
     78 #if GLIB_SIZEOF_VOID_P == 8
     79 #define G_POLLFD_FORMAT "%#I64x"
     80 #else
     81 #define G_POLLFD_FORMAT "%#x"
     82 #endif
     83 #else
     84 #define G_POLLFD_FORMAT "%d"
     85 #endif
     86 
     87 gint g_poll (GPollFD *fds,
     88 	     guint    nfds,
     89 	     gint     timeout);
     90 
     91 G_END_DECLS
     92 
     93 #endif /* __G_POLL_H__ */
     94