ac6424b981
Rename: wait_queue_t => wait_queue_entry_t 'wait_queue_t' was always a slight misnomer: its name implies that it's a "queue", but in reality it's a queue *entry*. The 'real' queue is the wait queue head, which had to carry the name. Start sorting this out by renaming it to 'wait_queue_entry_t'. This also allows the real structure name 'struct __wait_queue' to lose its double underscore and become 'struct wait_queue_entry', which is the more canonical nomenclature for such data types. Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
110 lines
3.1 KiB
C
110 lines
3.1 KiB
C
#ifndef _LINUX_POLL_H
|
|
#define _LINUX_POLL_H
|
|
|
|
|
|
#include <linux/compiler.h>
|
|
#include <linux/ktime.h>
|
|
#include <linux/wait.h>
|
|
#include <linux/string.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/sysctl.h>
|
|
#include <linux/uaccess.h>
|
|
#include <uapi/linux/poll.h>
|
|
|
|
extern struct ctl_table epoll_table[]; /* for sysctl */
|
|
/* ~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 *);
|
|
|
|
/*
|
|
* Do not touch the structure directly, use the access functions
|
|
* poll_does_not_wait() and poll_requested_events() instead.
|
|
*/
|
|
typedef struct poll_table_struct {
|
|
poll_queue_proc _qproc;
|
|
unsigned long _key;
|
|
} poll_table;
|
|
|
|
static inline void poll_wait(struct file * filp, wait_queue_head_t * wait_address, poll_table *p)
|
|
{
|
|
if (p && p->_qproc && wait_address)
|
|
p->_qproc(filp, wait_address, p);
|
|
}
|
|
|
|
/*
|
|
* Return true if it is guaranteed that poll will not wait. This is the case
|
|
* if the poll() of another file descriptor in the set got an event, so there
|
|
* is no need for waiting.
|
|
*/
|
|
static inline bool poll_does_not_wait(const poll_table *p)
|
|
{
|
|
return p == NULL || p->_qproc == NULL;
|
|
}
|
|
|
|
/*
|
|
* Return the set of events that the application wants to poll for.
|
|
* This is useful for drivers that need to know whether a DMA transfer has
|
|
* to be started implicitly on poll(). You typically only want to do that
|
|
* if the application is actually polling for POLLIN and/or POLLOUT.
|
|
*/
|
|
static inline unsigned long poll_requested_events(const poll_table *p)
|
|
{
|
|
return p ? p->_key : ~0UL;
|
|
}
|
|
|
|
static inline void init_poll_funcptr(poll_table *pt, poll_queue_proc qproc)
|
|
{
|
|
pt->_qproc = qproc;
|
|
pt->_key = ~0UL; /* all events enabled */
|
|
}
|
|
|
|
struct poll_table_entry {
|
|
struct file *filp;
|
|
unsigned long key;
|
|
wait_queue_entry_t wait;
|
|
wait_queue_head_t *wait_address;
|
|
};
|
|
|
|
/*
|
|
* Structures and helpers for select/poll syscall
|
|
*/
|
|
struct poll_wqueues {
|
|
poll_table pt;
|
|
struct poll_table_page *table;
|
|
struct task_struct *polling_task;
|
|
int triggered;
|
|
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);
|
|
extern int poll_schedule_timeout(struct poll_wqueues *pwq, int state,
|
|
ktime_t *expires, unsigned long slack);
|
|
extern u64 select_estimate_accuracy(struct timespec64 *tv);
|
|
|
|
#define MAX_INT64_SECONDS (((s64)(~((u64)0)>>1)/HZ)-1)
|
|
|
|
extern int core_sys_select(int n, fd_set __user *inp, fd_set __user *outp,
|
|
fd_set __user *exp, struct timespec64 *end_time);
|
|
|
|
extern int poll_select_set_timeout(struct timespec64 *to, time64_t sec,
|
|
long nsec);
|
|
|
|
#endif /* _LINUX_POLL_H */
|