~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/include/linux/poll.h

Version: ~ [ linux-5.16 ] ~ [ linux-5.15.13 ] ~ [ linux-5.14.21 ] ~ [ linux-5.13.19 ] ~ [ linux-5.12.19 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.90 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.170 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.224 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.261 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.296 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.298 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.18.140 ] ~ [ linux-3.16.85 ] ~ [ linux-3.14.79 ] ~ [ linux-3.12.74 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 #ifndef _LINUX_POLL_H
  2 #define _LINUX_POLL_H
  3 
  4 
  5 #include <linux/compiler.h>
  6 #include <linux/ktime.h>
  7 #include <linux/wait.h>
  8 #include <linux/string.h>
  9 #include <linux/fs.h>
 10 #include <linux/sysctl.h>
 11 #include <asm/uaccess.h>
 12 #include <uapi/linux/poll.h>
 13 
 14 extern struct ctl_table epoll_table[]; /* for sysctl */
 15 /* ~832 bytes of stack space used max in sys_select/sys_poll before allocating
 16    additional memory. */
 17 #define MAX_STACK_ALLOC 832
 18 #define FRONTEND_STACK_ALLOC    256
 19 #define SELECT_STACK_ALLOC      FRONTEND_STACK_ALLOC
 20 #define POLL_STACK_ALLOC        FRONTEND_STACK_ALLOC
 21 #define WQUEUES_STACK_ALLOC     (MAX_STACK_ALLOC - FRONTEND_STACK_ALLOC)
 22 #define N_INLINE_POLL_ENTRIES   (WQUEUES_STACK_ALLOC / sizeof(struct poll_table_entry))
 23 
 24 #define DEFAULT_POLLMASK (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)
 25 
 26 struct poll_table_struct;
 27 
 28 /* 
 29  * structures and helpers for f_op->poll implementations
 30  */
 31 typedef void (*poll_queue_proc)(struct file *, wait_queue_head_t *, struct poll_table_struct *);
 32 
 33 /*
 34  * Do not touch the structure directly, use the access functions
 35  * poll_does_not_wait() and poll_requested_events() instead.
 36  */
 37 typedef struct poll_table_struct {
 38         poll_queue_proc _qproc;
 39         unsigned long _key;
 40 } poll_table;
 41 
 42 static inline void poll_wait(struct file * filp, wait_queue_head_t * wait_address, poll_table *p)
 43 {
 44         if (p && p->_qproc && wait_address)
 45                 p->_qproc(filp, wait_address, p);
 46 }
 47 
 48 /*
 49  * Return true if it is guaranteed that poll will not wait. This is the case
 50  * if the poll() of another file descriptor in the set got an event, so there
 51  * is no need for waiting.
 52  */
 53 static inline bool poll_does_not_wait(const poll_table *p)
 54 {
 55         return p == NULL || p->_qproc == NULL;
 56 }
 57 
 58 /*
 59  * Return the set of events that the application wants to poll for.
 60  * This is useful for drivers that need to know whether a DMA transfer has
 61  * to be started implicitly on poll(). You typically only want to do that
 62  * if the application is actually polling for POLLIN and/or POLLOUT.
 63  */
 64 static inline unsigned long poll_requested_events(const poll_table *p)
 65 {
 66         return p ? p->_key : ~0UL;
 67 }
 68 
 69 static inline void init_poll_funcptr(poll_table *pt, poll_queue_proc qproc)
 70 {
 71         pt->_qproc = qproc;
 72         pt->_key   = ~0UL; /* all events enabled */
 73 }
 74 
 75 struct poll_table_entry {
 76         struct file *filp;
 77         unsigned long key;
 78         wait_queue_t wait;
 79         wait_queue_head_t *wait_address;
 80 };
 81 
 82 /*
 83  * Structures and helpers for select/poll syscall
 84  */
 85 struct poll_wqueues {
 86         poll_table pt;
 87         struct poll_table_page *table;
 88         struct task_struct *polling_task;
 89         int triggered;
 90         int error;
 91         int inline_index;
 92         struct poll_table_entry inline_entries[N_INLINE_POLL_ENTRIES];
 93 };
 94 
 95 extern void poll_initwait(struct poll_wqueues *pwq);
 96 extern void poll_freewait(struct poll_wqueues *pwq);
 97 extern int poll_schedule_timeout(struct poll_wqueues *pwq, int state,
 98                                  ktime_t *expires, unsigned long slack);
 99 extern long select_estimate_accuracy(struct timespec *tv);
100 
101 
102 static inline int poll_schedule(struct poll_wqueues *pwq, int state)
103 {
104         return poll_schedule_timeout(pwq, state, NULL, 0);
105 }
106 
107 /*
108  * Scalable version of the fd_set.
109  */
110 
111 typedef struct {
112         unsigned long *in, *out, *ex;
113         unsigned long *res_in, *res_out, *res_ex;
114 } fd_set_bits;
115 
116 /*
117  * How many longwords for "nr" bits?
118  */
119 #define FDS_BITPERLONG  (8*sizeof(long))
120 #define FDS_LONGS(nr)   (((nr)+FDS_BITPERLONG-1)/FDS_BITPERLONG)
121 #define FDS_BYTES(nr)   (FDS_LONGS(nr)*sizeof(long))
122 
123 /*
124  * We do a VERIFY_WRITE here even though we are only reading this time:
125  * we'll write to it eventually..
126  *
127  * Use "unsigned long" accesses to let user-mode fd_set's be long-aligned.
128  */
129 static inline
130 int get_fd_set(unsigned long nr, void __user *ufdset, unsigned long *fdset)
131 {
132         nr = FDS_BYTES(nr);
133         if (ufdset)
134                 return copy_from_user(fdset, ufdset, nr) ? -EFAULT : 0;
135 
136         memset(fdset, 0, nr);
137         return 0;
138 }
139 
140 static inline unsigned long __must_check
141 set_fd_set(unsigned long nr, void __user *ufdset, unsigned long *fdset)
142 {
143         if (ufdset)
144                 return __copy_to_user(ufdset, fdset, FDS_BYTES(nr));
145         return 0;
146 }
147 
148 static inline
149 void zero_fd_set(unsigned long nr, unsigned long *fdset)
150 {
151         memset(fdset, 0, FDS_BYTES(nr));
152 }
153 
154 #define MAX_INT64_SECONDS (((s64)(~((u64)0)>>1)/HZ)-1)
155 
156 extern int do_select(int n, fd_set_bits *fds, struct timespec *end_time);
157 extern int do_sys_poll(struct pollfd __user * ufds, unsigned int nfds,
158                        struct timespec *end_time);
159 extern int core_sys_select(int n, fd_set __user *inp, fd_set __user *outp,
160                            fd_set __user *exp, struct timespec *end_time);
161 
162 extern int poll_select_set_timeout(struct timespec *to, long sec, long nsec);
163 
164 #endif /* _LINUX_POLL_H */
165 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp