| Davidlohr Bueso | a043971 | 2013-12-14 20:31:55 -0800 | [diff] [blame] | 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 | |
| Davidlohr Bueso | 27db783 | 2013-12-14 20:31:56 -0800 | [diff] [blame] | 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 | |
| Davidlohr Bueso | 0fb298c | 2013-12-14 20:31:57 -0800 | [diff] [blame] | 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 | |
| Davidlohr Bueso | a043971 | 2013-12-14 20:31:55 -0800 | [diff] [blame] | 71 | #endif /* _FUTEX_H */ |