diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/linux/eventpoll.h |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'include/linux/eventpoll.h')
-rw-r--r-- | include/linux/eventpoll.h | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/include/linux/eventpoll.h b/include/linux/eventpoll.h new file mode 100644 index 000000000000..1289f0ec4c00 --- /dev/null +++ b/include/linux/eventpoll.h | |||
@@ -0,0 +1,99 @@ | |||
1 | /* | ||
2 | * include/linux/eventpoll.h ( Efficent event polling implementation ) | ||
3 | * Copyright (C) 2001,...,2003 Davide Libenzi | ||
4 | * | ||
5 | * This program is free software; you can redistribute it and/or modify | ||
6 | * it under the terms of the GNU General Public License as published by | ||
7 | * the Free Software Foundation; either version 2 of the License, or | ||
8 | * (at your option) any later version. | ||
9 | * | ||
10 | * Davide Libenzi <davidel@xmailserver.org> | ||
11 | * | ||
12 | */ | ||
13 | |||
14 | #ifndef _LINUX_EVENTPOLL_H | ||
15 | #define _LINUX_EVENTPOLL_H | ||
16 | |||
17 | #include <linux/types.h> | ||
18 | |||
19 | |||
20 | /* Valid opcodes to issue to sys_epoll_ctl() */ | ||
21 | #define EPOLL_CTL_ADD 1 | ||
22 | #define EPOLL_CTL_DEL 2 | ||
23 | #define EPOLL_CTL_MOD 3 | ||
24 | |||
25 | /* Set the One Shot behaviour for the target file descriptor */ | ||
26 | #define EPOLLONESHOT (1 << 30) | ||
27 | |||
28 | /* Set the Edge Triggered behaviour for the target file descriptor */ | ||
29 | #define EPOLLET (1 << 31) | ||
30 | |||
31 | /* | ||
32 | * On x86-64 make the 64bit structure have the same alignment as the | ||
33 | * 32bit structure. This makes 32bit emulation easier. | ||
34 | */ | ||
35 | #ifdef __x86_64__ | ||
36 | #define EPOLL_PACKED __attribute__((packed)) | ||
37 | #else | ||
38 | #define EPOLL_PACKED | ||
39 | #endif | ||
40 | |||
41 | struct epoll_event { | ||
42 | __u32 events; | ||
43 | __u64 data; | ||
44 | } EPOLL_PACKED; | ||
45 | |||
46 | #ifdef __KERNEL__ | ||
47 | |||
48 | /* Forward declarations to avoid compiler errors */ | ||
49 | struct file; | ||
50 | |||
51 | |||
52 | #ifdef CONFIG_EPOLL | ||
53 | |||
54 | /* Used to initialize the epoll bits inside the "struct file" */ | ||
55 | void eventpoll_init_file(struct file *file); | ||
56 | |||
57 | /* Used to release the epoll bits inside the "struct file" */ | ||
58 | void eventpoll_release_file(struct file *file); | ||
59 | |||
60 | /* | ||
61 | * This is called from inside fs/file_table.c:__fput() to unlink files | ||
62 | * from the eventpoll interface. We need to have this facility to cleanup | ||
63 | * correctly files that are closed without being removed from the eventpoll | ||
64 | * interface. | ||
65 | */ | ||
66 | static inline void eventpoll_release(struct file *file) | ||
67 | { | ||
68 | |||
69 | /* | ||
70 | * Fast check to avoid the get/release of the semaphore. Since | ||
71 | * we're doing this outside the semaphore lock, it might return | ||
72 | * false negatives, but we don't care. It'll help in 99.99% of cases | ||
73 | * to avoid the semaphore lock. False positives simply cannot happen | ||
74 | * because the file in on the way to be removed and nobody ( but | ||
75 | * eventpoll ) has still a reference to this file. | ||
76 | */ | ||
77 | if (likely(list_empty(&file->f_ep_links))) | ||
78 | return; | ||
79 | |||
80 | /* | ||
81 | * The file is being closed while it is still linked to an epoll | ||
82 | * descriptor. We need to handle this by correctly unlinking it | ||
83 | * from its containers. | ||
84 | */ | ||
85 | eventpoll_release_file(file); | ||
86 | } | ||
87 | |||
88 | |||
89 | #else | ||
90 | |||
91 | static inline void eventpoll_init_file(struct file *file) {} | ||
92 | static inline void eventpoll_release(struct file *file) {} | ||
93 | |||
94 | #endif | ||
95 | |||
96 | #endif /* #ifdef __KERNEL__ */ | ||
97 | |||
98 | #endif /* #ifndef _LINUX_EVENTPOLL_H */ | ||
99 | |||