| 1 | /* gpoll.h - poll(2) support |
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| 2 | * Copyright (C) 2008 Red Hat, Inc. |
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| 3 | * |
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| 4 | * This library is free software; you can redistribute it and/or |
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| 5 | * modify it under the terms of the GNU Lesser General Public |
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| 6 | * License as published by the Free Software Foundation; either |
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| 7 | * version 2.1 of the License, or (at your option) any later version. |
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| 8 | * |
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| 9 | * This library is distributed in the hope that it will be useful, |
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| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 12 | * Lesser General Public License for more details. |
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| 13 | * |
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| 14 | * You should have received a copy of the GNU Lesser General Public License |
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| 15 | * along with this library; if not, see <http://www.gnu.org/licenses/>. |
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| 16 | */ |
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| 17 | |
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| 18 | #ifndef __G_POLL_H__ |
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| 19 | #define __G_POLL_H__ |
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| 20 | |
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| 21 | #if !defined (__GLIB_H_INSIDE__) && !defined (__G_MAIN_H__) && !defined (GLIB_COMPILATION) |
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| 22 | #error "Only <glib.h> can be included directly." |
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| 23 | #endif |
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| 24 | |
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| 25 | #include <glibconfig.h> |
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| 26 | #include <glib/gtypes.h> |
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| 27 | |
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| 28 | G_BEGIN_DECLS |
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| 29 | |
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| 30 | /* Any definitions using GPollFD or GPollFunc are primarily |
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| 31 | * for Unix and not guaranteed to be the compatible on all |
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| 32 | * operating systems on which GLib runs. Right now, the |
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| 33 | * GLib does use these functions on Win32 as well, but interprets |
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| 34 | * them in a fairly different way than on Unix. If you use |
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| 35 | * these definitions, you are should be prepared to recode |
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| 36 | * for different operating systems. |
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| 37 | * |
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| 38 | * Note that on systems with a working poll(2), that function is used |
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| 39 | * in place of g_poll(). Thus g_poll() must have the same signature as |
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| 40 | * poll(), meaning GPollFD must have the same layout as struct pollfd. |
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| 41 | * |
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| 42 | * On Win32, the fd in a GPollFD should be Win32 HANDLE (*not* a file |
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| 43 | * descriptor as provided by the C runtime) that can be used by |
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| 44 | * MsgWaitForMultipleObjects. This does *not* include file handles |
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| 45 | * from CreateFile, SOCKETs, nor pipe handles. (But you can use |
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| 46 | * WSAEventSelect to signal events when a SOCKET is readable). |
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| 47 | * |
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| 48 | * On Win32, fd can also be the special value G_WIN32_MSG_HANDLE to |
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| 49 | * indicate polling for messages. |
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| 50 | * |
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| 51 | * But note that G_WIN32_MSG_HANDLE GPollFDs should not be used by GDK |
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| 52 | * (GTK) programs, as GDK itself wants to read messages and convert them |
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| 53 | * to GDK events. |
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| 54 | * |
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| 55 | * So, unless you really know what you are doing, it's best not to try |
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| 56 | * to use the main loop polling stuff for your own needs on |
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| 57 | * Windows. |
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| 58 | */ |
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| 59 | typedef struct _GPollFD GPollFD; |
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| 60 | |
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| 61 | /** |
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| 62 | * GPollFunc: |
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| 63 | * @ufds: an array of #GPollFD elements |
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| 64 | * @nfsd: the number of elements in @ufds |
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| 65 | * @timeout_: the maximum time to wait for an event of the file descriptors. |
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| 66 | * A negative value indicates an infinite timeout. |
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| 67 | * |
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| 68 | * Specifies the type of function passed to g_main_context_set_poll_func(). |
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| 69 | * The semantics of the function should match those of the poll() system call. |
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| 70 | * |
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| 71 | * Returns: the number of #GPollFD elements which have events or errors |
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| 72 | * reported, or -1 if an error occurred. |
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| 73 | */ |
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| 74 | typedef gint (*GPollFunc) (GPollFD *ufds, |
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| 75 | guint nfsd, |
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| 76 | gint timeout_); |
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| 77 | |
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| 78 | /** |
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| 79 | * GPollFD: |
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| 80 | * @fd: the file descriptor to poll (or a HANDLE on Win32) |
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| 81 | * @events: a bitwise combination from #GIOCondition, specifying which |
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| 82 | * events should be polled for. Typically for reading from a file |
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| 83 | * descriptor you would use %G_IO_IN | %G_IO_HUP | %G_IO_ERR, and |
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| 84 | * for writing you would use %G_IO_OUT | %G_IO_ERR. |
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| 85 | * @revents: a bitwise combination of flags from #GIOCondition, returned |
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| 86 | * from the poll() function to indicate which events occurred. |
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| 87 | * |
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| 88 | * Represents a file descriptor, which events to poll for, and which events |
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| 89 | * occurred. |
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| 90 | */ |
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| 91 | struct _GPollFD |
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| 92 | { |
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| 93 | #if defined (G_OS_WIN32) && GLIB_SIZEOF_VOID_P == 8 |
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| 94 | #ifndef __GTK_DOC_IGNORE__ |
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| 95 | gint64 fd; |
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| 96 | #endif |
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| 97 | #else |
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| 98 | gint fd; |
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| 99 | #endif |
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| 100 | gushort events; |
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| 101 | gushort revents; |
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| 102 | }; |
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| 103 | |
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| 104 | /** |
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| 105 | * G_POLLFD_FORMAT: |
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| 106 | * |
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| 107 | * A format specifier that can be used in printf()-style format strings |
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| 108 | * when printing the @fd member of a #GPollFD. |
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| 109 | */ |
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| 110 | /* defined in glibconfig.h */ |
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| 111 | |
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| 112 | GLIB_AVAILABLE_IN_ALL |
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| 113 | gint |
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| 114 | g_poll (GPollFD *fds, |
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| 115 | guint nfds, |
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| 116 | gint timeout); |
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| 117 | |
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| 118 | G_END_DECLS |
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| 119 | |
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| 120 | #endif /* __G_POLL_H__ */ |
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| 121 | |
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