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_lock_pi() - block on uaddr as a PI mutex 60 */ 61 static inline int 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 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 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> 91 #include <linux/compiler.h> 92 static inline int pthread_attr_setaffinity_np(pthread_attr_t *attr __maybe_unused, 93 size_t cpusetsize __maybe_unused, 94 cpu_set_t *cpuset __maybe_unused) 95 { 96 return 0; 97 } 98 #endif 99 100 #endif /* _FUTEX_H */ 101