LXR linux/tools/perf/bench/futex.h

   1/*
   2 * Glibc independent futex library for testing kernel functionality.
   3 * Shamelessly stolen from Darren Hart <dvhltc@us.ibm.com>
   4 *    http://git.kernel.org/cgit/linux/kernel/git/dvhart/futextest.git/
   5 */
   6
   7#ifndef _FUTEX_H
   8#define _FUTEX_H
   9
  10#include <unistd.h>
  11#include <sys/syscall.h>
  12#include <sys/types.h>
  13#include <linux/futex.h>
  14
  15/**
  16 * futex() - SYS_futex syscall wrapper
  17 * @uaddr:      address of first futex
  18 * @op:         futex op code
  19 * @val:        typically expected value of uaddr, but varies by op
  20 * @timeout:    typically an absolute struct timespec (except where noted
  21 *              otherwise). Overloaded by some ops
  22 * @uaddr2:     address of second futex for some ops\
  23 * @val3:       varies by op
  24 * @opflags:    flags to be bitwise OR'd with op, such as FUTEX_PRIVATE_FLAG
  25 *
  26 * futex() is used by all the following futex op wrappers. It can also be
  27 * used for misuse and abuse testing. Generally, the specific op wrappers
  28 * should be used instead. It is a macro instead of an static inline function as
  29 * some of the types over overloaded (timeout is used for nr_requeue for
  30 * example).
  31 *
  32 * These argument descriptions are the defaults for all
  33 * like-named arguments in the following wrappers except where noted below.
  34 */
  35#define futex(uaddr, op, val, timeout, uaddr2, val3, opflags) \
  36        syscall(SYS_futex, uaddr, op | opflags, val, timeout, uaddr2, val3)
  37
  38/**
  39 * futex_wait() - block on uaddr with optional timeout
  40 * @timeout:    relative timeout
  41 */
  42static inline int
  43futex_wait(u_int32_t *uaddr, u_int32_t val, struct timespec *timeout, int opflags)
  44{
  45        return futex(uaddr, FUTEX_WAIT, val, timeout, NULL, 0, opflags);
  46}
  47
  48/**
  49 * futex_wake() - wake one or more tasks blocked on uaddr
  50 * @nr_wake:    wake up to this many tasks
  51 */
  52static inline int
  53futex_wake(u_int32_t *uaddr, int nr_wake, int opflags)
  54{
  55        return futex(uaddr, FUTEX_WAKE, nr_wake, NULL, NULL, 0, opflags);
  56}
  57
  58/**
  59 * futex_lock_pi() - block on uaddr as a PI mutex
  60 */
  61static inline int
  62futex_lock_pi(u_int32_t *uaddr, struct timespec *timeout, int opflags)
  63{
  64        return futex(uaddr, FUTEX_LOCK_PI, 0, timeout, NULL, 0, opflags);
  65}
  66
  67/**
  68 * futex_unlock_pi() - release uaddr as a PI mutex, waking the top waiter
  69 */
  70static inline int
  71futex_unlock_pi(u_int32_t *uaddr, int opflags)
  72{
  73        return futex(uaddr, FUTEX_UNLOCK_PI, 0, NULL, NULL, 0, opflags);
  74}
  75
  76/**
  77* futex_cmp_requeue() - requeue tasks from uaddr to uaddr2
  78* @nr_wake:        wake up to this many tasks
  79* @nr_requeue:        requeue up to this many tasks
  80*/
  81static inline int
  82futex_cmp_requeue(u_int32_t *uaddr, u_int32_t val, u_int32_t *uaddr2, int nr_wake,
  83                 int nr_requeue, int opflags)
  84{
  85        return futex(uaddr, FUTEX_CMP_REQUEUE, nr_wake, nr_requeue, uaddr2,
  86                 val, opflags);
  87}
  88
  89#ifndef HAVE_PTHREAD_ATTR_SETAFFINITY_NP
  90#include <pthread.h>
  91static inline int pthread_attr_setaffinity_np(pthread_attr_t *attr,
  92                                              size_t cpusetsize,
  93                                              cpu_set_t *cpuset)
  94{
  95        attr = attr;
  96        cpusetsize = cpusetsize;
  97        cpuset = cpuset;
  98        return 0;
  99}
 100#endif
 101
 102#endif /* _FUTEX_H */
 103