xref: /linux/tools/perf/bench/futex.h (revision c0e297dc61f8d4453e07afbea1fa8d0e67cd4a34)
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
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
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_cmp_requeue() - requeue tasks from uaddr to uaddr2
60 * @nr_wake:        wake up to this many tasks
61 * @nr_requeue:        requeue up to this many tasks
62 */
63 static inline int
64 futex_cmp_requeue(u_int32_t *uaddr, u_int32_t val, u_int32_t *uaddr2, int nr_wake,
65 		 int nr_requeue, int opflags)
66 {
67 	return futex(uaddr, FUTEX_CMP_REQUEUE, nr_wake, nr_requeue, uaddr2,
68 		 val, opflags);
69 }
70 
71 #ifndef HAVE_PTHREAD_ATTR_SETAFFINITY_NP
72 #include <pthread.h>
73 static inline int pthread_attr_setaffinity_np(pthread_attr_t *attr,
74 					      size_t cpusetsize,
75 					      cpu_set_t *cpuset)
76 {
77 	attr = attr;
78 	cpusetsize = cpusetsize;
79 	cpuset = cpuset;
80 	return 0;
81 }
82 #endif
83 
84 #endif /* _FUTEX_H */
85