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 */
42 static inline int
futex_wait(u_int32_t * uaddr,u_int32_t val,struct timespec * timeout,int opflags)43 futex_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 */
52 static inline int
futex_wake(u_int32_t * uaddr,int nr_wake,int opflags)53 futex_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 */
61 static inline int
futex_lock_pi(u_int32_t * uaddr,struct timespec * timeout,int opflags)62 futex_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 */
70 static inline int
futex_unlock_pi(u_int32_t * uaddr,int opflags)71 futex_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 */
81 static inline int
futex_cmp_requeue(u_int32_t * uaddr,u_int32_t val,u_int32_t * uaddr2,int nr_wake,int nr_requeue,int opflags)82 futex_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>
pthread_attr_setaffinity_np(pthread_attr_t * attr,size_t cpusetsize,cpu_set_t * cpuset)91 static 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