diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-17 02:20:36 +0400 |
---|---|---|
committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-17 02:20:36 +0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/linux/eventpoll.h | |
download | linux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.xz |
Linux-2.6.12-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 @@ +/* + * include/linux/eventpoll.h ( Efficent event polling implementation ) + * Copyright (C) 2001,...,2003 Davide Libenzi + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * Davide Libenzi <davidel@xmailserver.org> + * + */ + +#ifndef _LINUX_EVENTPOLL_H +#define _LINUX_EVENTPOLL_H + +#include <linux/types.h> + + +/* Valid opcodes to issue to sys_epoll_ctl() */ +#define EPOLL_CTL_ADD 1 +#define EPOLL_CTL_DEL 2 +#define EPOLL_CTL_MOD 3 + +/* Set the One Shot behaviour for the target file descriptor */ +#define EPOLLONESHOT (1 << 30) + +/* Set the Edge Triggered behaviour for the target file descriptor */ +#define EPOLLET (1 << 31) + +/* + * On x86-64 make the 64bit structure have the same alignment as the + * 32bit structure. This makes 32bit emulation easier. + */ +#ifdef __x86_64__ +#define EPOLL_PACKED __attribute__((packed)) +#else +#define EPOLL_PACKED +#endif + +struct epoll_event { + __u32 events; + __u64 data; +} EPOLL_PACKED; + +#ifdef __KERNEL__ + +/* Forward declarations to avoid compiler errors */ +struct file; + + +#ifdef CONFIG_EPOLL + +/* Used to initialize the epoll bits inside the "struct file" */ +void eventpoll_init_file(struct file *file); + +/* Used to release the epoll bits inside the "struct file" */ +void eventpoll_release_file(struct file *file); + +/* + * This is called from inside fs/file_table.c:__fput() to unlink files + * from the eventpoll interface. We need to have this facility to cleanup + * correctly files that are closed without being removed from the eventpoll + * interface. + */ +static inline void eventpoll_release(struct file *file) +{ + + /* + * Fast check to avoid the get/release of the semaphore. Since + * we're doing this outside the semaphore lock, it might return + * false negatives, but we don't care. It'll help in 99.99% of cases + * to avoid the semaphore lock. False positives simply cannot happen + * because the file in on the way to be removed and nobody ( but + * eventpoll ) has still a reference to this file. + */ + if (likely(list_empty(&file->f_ep_links))) + return; + + /* + * The file is being closed while it is still linked to an epoll + * descriptor. We need to handle this by correctly unlinking it + * from its containers. + */ + eventpoll_release_file(file); +} + + +#else + +static inline void eventpoll_init_file(struct file *file) {} +static inline void eventpoll_release(struct file *file) {} + +#endif + +#endif /* #ifdef __KERNEL__ */ + +#endif /* #ifndef _LINUX_EVENTPOLL_H */ + |