kernel-ark/include/linux/poll.h
Arjan van de Ven 8ff3e8e85f select: switch select() and poll() over to hrtimers
With lots of help, input and cleanups from Thomas Gleixner

This patch switches select() and poll() over to hrtimers.

The core of the patch is replacing the "s64 timeout" with a
"struct timespec end_time" in all the plumbing.

But most of the diffstat comes from using the just introduced helpers:
	poll_select_set_timeout
	poll_select_copy_remaining
	timespec_add_safe
which make manipulating the timespec easier and less error-prone.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-09-05 21:35:03 -07:00

128 lines
3.2 KiB
C

#ifndef _LINUX_POLL_H
#define _LINUX_POLL_H
#include <asm/poll.h>
#ifdef __KERNEL__
#include <linux/compiler.h>
#include <linux/wait.h>
#include <linux/string.h>
#include <linux/fs.h>
#include <linux/sched.h>
#include <asm/uaccess.h>
/* ~832 bytes of stack space used max in sys_select/sys_poll before allocating
additional memory. */
#define MAX_STACK_ALLOC 832
#define FRONTEND_STACK_ALLOC 256
#define SELECT_STACK_ALLOC FRONTEND_STACK_ALLOC
#define POLL_STACK_ALLOC FRONTEND_STACK_ALLOC
#define WQUEUES_STACK_ALLOC (MAX_STACK_ALLOC - FRONTEND_STACK_ALLOC)
#define N_INLINE_POLL_ENTRIES (WQUEUES_STACK_ALLOC / sizeof(struct poll_table_entry))
#define DEFAULT_POLLMASK (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)
struct poll_table_struct;
/*
* structures and helpers for f_op->poll implementations
*/
typedef void (*poll_queue_proc)(struct file *, wait_queue_head_t *, struct poll_table_struct *);
typedef struct poll_table_struct {
poll_queue_proc qproc;
} poll_table;
static inline void poll_wait(struct file * filp, wait_queue_head_t * wait_address, poll_table *p)
{
if (p && wait_address)
p->qproc(filp, wait_address, p);
}
static inline void init_poll_funcptr(poll_table *pt, poll_queue_proc qproc)
{
pt->qproc = qproc;
}
struct poll_table_entry {
struct file * filp;
wait_queue_t wait;
wait_queue_head_t * wait_address;
};
/*
* Structures and helpers for sys_poll/sys_poll
*/
struct poll_wqueues {
poll_table pt;
struct poll_table_page * table;
int error;
int inline_index;
struct poll_table_entry inline_entries[N_INLINE_POLL_ENTRIES];
};
extern void poll_initwait(struct poll_wqueues *pwq);
extern void poll_freewait(struct poll_wqueues *pwq);
/*
* Scaleable version of the fd_set.
*/
typedef struct {
unsigned long *in, *out, *ex;
unsigned long *res_in, *res_out, *res_ex;
} fd_set_bits;
/*
* How many longwords for "nr" bits?
*/
#define FDS_BITPERLONG (8*sizeof(long))
#define FDS_LONGS(nr) (((nr)+FDS_BITPERLONG-1)/FDS_BITPERLONG)
#define FDS_BYTES(nr) (FDS_LONGS(nr)*sizeof(long))
/*
* We do a VERIFY_WRITE here even though we are only reading this time:
* we'll write to it eventually..
*
* Use "unsigned long" accesses to let user-mode fd_set's be long-aligned.
*/
static inline
int get_fd_set(unsigned long nr, void __user *ufdset, unsigned long *fdset)
{
nr = FDS_BYTES(nr);
if (ufdset)
return copy_from_user(fdset, ufdset, nr) ? -EFAULT : 0;
memset(fdset, 0, nr);
return 0;
}
static inline unsigned long __must_check
set_fd_set(unsigned long nr, void __user *ufdset, unsigned long *fdset)
{
if (ufdset)
return __copy_to_user(ufdset, fdset, FDS_BYTES(nr));
return 0;
}
static inline
void zero_fd_set(unsigned long nr, unsigned long *fdset)
{
memset(fdset, 0, FDS_BYTES(nr));
}
#define MAX_INT64_SECONDS (((s64)(~((u64)0)>>1)/HZ)-1)
extern int do_select(int n, fd_set_bits *fds, struct timespec *end_time);
extern int do_sys_poll(struct pollfd __user * ufds, unsigned int nfds,
struct timespec *end_time);
extern int core_sys_select(int n, fd_set __user *inp, fd_set __user *outp,
fd_set __user *exp, struct timespec *end_time);
extern int poll_select_set_timeout(struct timespec *to, long sec, long nsec);
#endif /* KERNEL */
#endif /* _LINUX_POLL_H */