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a0439711 DB |
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 | ||
27db7830 DB |
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 | ||
0fb298cf DB |
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 | ||
a0439711 | 71 | #endif /* _FUTEX_H */ |