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

   1/* SPDX-License-Identifier: GPL-2.0 */
   2/*
   3 * Glibc independent futex library for testing kernel functionality.
   4 * Shamelessly stolen from Darren Hart <dvhltc@us.ibm.com>
   5 *    http://git.kernel.org/cgit/linux/kernel/git/dvhart/futextest.git/
   6 */
   7
   8#ifndef _FUTEX_H
   9#define _FUTEX_H
  10
  11#include <unistd.h>
  12#include <sys/syscall.h>
  13#include <sys/types.h>
  14#include <linux/futex.h>
  15
  16struct bench_futex_parameters {
  17        bool silent;
  18        bool fshared;
  19        bool mlockall;
  20        bool multi; /* lock-pi */
  21        bool pi; /* requeue-pi */
  22        bool broadcast; /* requeue */
  23        unsigned int runtime; /* seconds*/
  24        unsigned int nthreads;
  25        unsigned int nfutexes;
  26        unsigned int nwakes;
  27        unsigned int nrequeue;
  28};
  29
  30/**
  31 * futex() - SYS_futex syscall wrapper
  32 * @uaddr:      address of first futex
  33 * @op:         futex op code
  34 * @val:        typically expected value of uaddr, but varies by op
  35 * @timeout:    typically an absolute struct timespec (except where noted
  36 *              otherwise). Overloaded by some ops
  37 * @uaddr2:     address of second futex for some ops
  38 * @val3:       varies by op
  39 * @opflags:    flags to be bitwise OR'd with op, such as FUTEX_PRIVATE_FLAG
  40 *
  41 * futex() is used by all the following futex op wrappers. It can also be
  42 * used for misuse and abuse testing. Generally, the specific op wrappers
  43 * should be used instead. It is a macro instead of an static inline function as
  44 * some of the types over overloaded (timeout is used for nr_requeue for
  45 * example).
  46 *
  47 * These argument descriptions are the defaults for all
  48 * like-named arguments in the following wrappers except where noted below.
  49 */
  50#define futex(uaddr, op, val, timeout, uaddr2, val3, opflags) \
  51        syscall(SYS_futex, uaddr, op | opflags, val, timeout, uaddr2, val3)
  52
  53/**
  54 * futex_wait() - block on uaddr with optional timeout
  55 * @timeout:    relative timeout
  56 */
  57static inline int
  58futex_wait(u_int32_t *uaddr, u_int32_t val, struct timespec *timeout, int opflags)
  59{
  60        return futex(uaddr, FUTEX_WAIT, val, timeout, NULL, 0, opflags);
  61}
  62
  63/**
  64 * futex_wake() - wake one or more tasks blocked on uaddr
  65 * @nr_wake:    wake up to this many tasks
  66 */
  67static inline int
  68futex_wake(u_int32_t *uaddr, int nr_wake, int opflags)
  69{
  70        return futex(uaddr, FUTEX_WAKE, nr_wake, NULL, NULL, 0, opflags);
  71}
  72
  73/**
  74 * futex_lock_pi() - block on uaddr as a PI mutex
  75 */
  76static inline int
  77futex_lock_pi(u_int32_t *uaddr, struct timespec *timeout, int opflags)
  78{
  79        return futex(uaddr, FUTEX_LOCK_PI, 0, timeout, NULL, 0, opflags);
  80}
  81
  82/**
  83 * futex_unlock_pi() - release uaddr as a PI mutex, waking the top waiter
  84 */
  85static inline int
  86futex_unlock_pi(u_int32_t *uaddr, int opflags)
  87{
  88        return futex(uaddr, FUTEX_UNLOCK_PI, 0, NULL, NULL, 0, opflags);
  89}
  90
  91/**
  92* futex_cmp_requeue() - requeue tasks from uaddr to uaddr2
  93* @nr_wake:        wake up to this many tasks
  94* @nr_requeue:     requeue up to this many tasks
  95*/
  96static inline int
  97futex_cmp_requeue(u_int32_t *uaddr, u_int32_t val, u_int32_t *uaddr2, int nr_wake,
  98                 int nr_requeue, int opflags)
  99{
 100        return futex(uaddr, FUTEX_CMP_REQUEUE, nr_wake, nr_requeue, uaddr2,
 101                 val, opflags);
 102}
 103
 104/**
 105 * futex_wait_requeue_pi() - block on uaddr and prepare to requeue to uaddr2
 106 * @uaddr:      non-PI futex source
 107 * @uaddr2:     PI futex target
 108 *
 109 * This is the first half of the requeue_pi mechanism. It shall always be
 110 * paired with futex_cmp_requeue_pi().
 111 */
 112static inline int
 113futex_wait_requeue_pi(u_int32_t *uaddr, u_int32_t val, u_int32_t *uaddr2,
 114                      struct timespec *timeout, int opflags)
 115{
 116        return futex(uaddr, FUTEX_WAIT_REQUEUE_PI, val, timeout, uaddr2, 0,
 117                     opflags);
 118}
 119
 120/**
 121 * futex_cmp_requeue_pi() - requeue tasks from uaddr to uaddr2
 122 * @uaddr:      non-PI futex source
 123 * @uaddr2:     PI futex target
 124 * @nr_requeue: requeue up to this many tasks
 125 *
 126 * This is the second half of the requeue_pi mechanism. It shall always be
 127 * paired with futex_wait_requeue_pi(). The first waker is always awoken.
 128 */
 129static inline int
 130futex_cmp_requeue_pi(u_int32_t *uaddr, u_int32_t val, u_int32_t *uaddr2,
 131                     int nr_requeue, int opflags)
 132{
 133        return futex(uaddr, FUTEX_CMP_REQUEUE_PI, 1, nr_requeue, uaddr2,
 134                     val, opflags);
 135}
 136
 137#endif /* _FUTEX_H */
 138