Author: vangyzen Date: Thu Feb 23 19:36:38 2017 New Revision: 314179 URL: https://svnweb.freebsd.org/changeset/base/314179
Log: Add sem_clockwait_np() This function allows the caller to specify the reference clock and choose between absolute and relative mode. In relative mode, the remaining time can be returned. The API is similar to clock_nanosleep(3). Thanks to Ed Schouten for that suggestion. While I'm here, reduce the sleep time in the semaphore "child" test to greatly reduce its runtime. Also add a reasonable timeout. Reviewed by: ed (userland) MFC after: 2 weeks Relnotes: yes Sponsored by: Dell EMC Differential Revision: https://reviews.freebsd.org/D9656 Modified: head/contrib/netbsd-tests/lib/librt/t_sem.c head/include/semaphore.h head/lib/libc/gen/Makefile.inc head/lib/libc/gen/Symbol.map head/lib/libc/gen/sem_new.c head/lib/libc/gen/sem_timedwait.3 head/lib/libc/include/namespace.h head/lib/libc/include/un-namespace.h head/share/man/man3/pthread_testcancel.3 head/sys/kern/kern_umtx.c Modified: head/contrib/netbsd-tests/lib/librt/t_sem.c ============================================================================== --- head/contrib/netbsd-tests/lib/librt/t_sem.c Thu Feb 23 19:32:25 2017 (r314178) +++ head/contrib/netbsd-tests/lib/librt/t_sem.c Thu Feb 23 19:36:38 2017 (r314179) @@ -60,18 +60,24 @@ __COPYRIGHT("@(#) Copyright (c) 2008, 20 The NetBSD Foundation, inc. All rights reserved."); __RCSID("$NetBSD: t_sem.c,v 1.3 2017/01/14 20:58:20 christos Exp $"); +#include <sys/time.h> #include <sys/wait.h> #include <errno.h> #include <fcntl.h> #include <semaphore.h> +#include <signal.h> #include <stdio.h> +#include <time.h> #include <unistd.h> #include <atf-c.h> #define NCHILDREN 10 +#define SEM_REQUIRE(x) \ + ATF_REQUIRE_EQ_MSG(x, 0, "%s", strerror(errno)) + ATF_TC_WITH_CLEANUP(basic); ATF_TC_HEAD(basic, tc) { @@ -118,6 +124,7 @@ ATF_TC_HEAD(child, tc) { atf_tc_set_md_var(tc, "descr", "Checks using semaphores to synchronize " "parent with multiple child processes"); + atf_tc_set_md_var(tc, "timeout", "5"); } ATF_TC_BODY(child, tc) { @@ -153,7 +160,7 @@ ATF_TC_BODY(child, tc) } for (i = 0; i < NCHILDREN; i++) { - sleep(1); + usleep(100000); printf("main loop %d: posting...\n", j); ATF_REQUIRE_EQ(sem_post(sem_a), 0); } @@ -173,11 +180,151 @@ ATF_TC_CLEANUP(child, tc) (void)sem_unlink("/sem_a"); } +static inline void +timespec_add_ms(struct timespec *ts, int ms) +{ + ts->tv_nsec += ms * 1000*1000; + if (ts->tv_nsec > 1000*1000*1000) { + ts->tv_sec++; + ts->tv_nsec -= 1000*1000*1000; + } +} + +volatile sig_atomic_t got_sigalrm = 0; + +static void +sigalrm_handler(int sig __unused) +{ + got_sigalrm = 1; +} + +ATF_TC(timedwait); +ATF_TC_HEAD(timedwait, tc) +{ + atf_tc_set_md_var(tc, "descr", "Tests sem_timedwait(3)" +#ifdef __FreeBSD__ + " and sem_clockwait_np(3)" +#endif + ); + atf_tc_set_md_var(tc, "timeout", "20"); +} +ATF_TC_BODY(timedwait, tc) +{ + struct timespec ts; + sem_t sem; + int result; + + SEM_REQUIRE(sem_init(&sem, 0, 0)); + SEM_REQUIRE(sem_post(&sem)); + ATF_REQUIRE_MSG(clock_gettime(CLOCK_REALTIME, &ts) == 0, + "%s", strerror(errno)); + timespec_add_ms(&ts, 100); + SEM_REQUIRE(sem_timedwait(&sem, &ts)); + ATF_REQUIRE_ERRNO(ETIMEDOUT, sem_timedwait(&sem, &ts)); + ts.tv_sec--; + ATF_REQUIRE_ERRNO(ETIMEDOUT, sem_timedwait(&sem, &ts)); + SEM_REQUIRE(sem_post(&sem)); + SEM_REQUIRE(sem_timedwait(&sem, &ts)); + + /* timespec validation, in the past */ + ts.tv_nsec += 1000*1000*1000; + ATF_REQUIRE_ERRNO(EINVAL, sem_timedwait(&sem, &ts)); + ts.tv_nsec = -1; + ATF_REQUIRE_ERRNO(EINVAL, sem_timedwait(&sem, &ts)); + /* timespec validation, in the future */ + ATF_REQUIRE_MSG(clock_gettime(CLOCK_REALTIME, &ts) == 0, + "%s", strerror(errno)); + ts.tv_sec++; + ts.tv_nsec = 1000*1000*1000; + ATF_REQUIRE_ERRNO(EINVAL, sem_timedwait(&sem, &ts)); + ts.tv_nsec = -1; + ATF_REQUIRE_ERRNO(EINVAL, sem_timedwait(&sem, &ts)); + + /* EINTR */ + struct sigaction act = { + .sa_handler = sigalrm_handler, + .sa_flags = 0 /* not SA_RESTART */ + }; + ATF_REQUIRE_MSG(sigemptyset(&act.sa_mask) == 0, + "%s", strerror(errno)); + ATF_REQUIRE_MSG(sigaction(SIGALRM, &act, NULL) == 0, + "%s", strerror(errno)); + struct itimerval it = { + .it_value.tv_usec = 50*1000 + }; + ATF_REQUIRE_MSG(setitimer(ITIMER_REAL, &it, NULL) == 0, + "%s", strerror(errno)); + ATF_REQUIRE_MSG(clock_gettime(CLOCK_REALTIME, &ts) == 0, + "%s", strerror(errno)); + timespec_add_ms(&ts, 100); + ATF_REQUIRE_ERRNO(EINTR, sem_timedwait(&sem, &ts)); + ATF_REQUIRE_MSG(got_sigalrm, "did not get SIGALRM"); + +#ifdef __FreeBSD__ + /* CLOCK_MONOTONIC, absolute */ + SEM_REQUIRE(sem_post(&sem)); + ATF_REQUIRE_MSG(clock_gettime(CLOCK_MONOTONIC, &ts) == 0, + "%s", strerror(errno)); + timespec_add_ms(&ts, 100); + SEM_REQUIRE(sem_clockwait_np(&sem, CLOCK_MONOTONIC, TIMER_ABSTIME, + &ts, NULL)); + ATF_REQUIRE_ERRNO(ETIMEDOUT, + sem_clockwait_np(&sem, CLOCK_MONOTONIC, TIMER_ABSTIME, &ts, NULL)); + + /* CLOCK_MONOTONIC, relative */ + SEM_REQUIRE(sem_post(&sem)); + ts.tv_sec = 0; + ts.tv_nsec = 100*1000*1000; + SEM_REQUIRE(sem_clockwait_np(&sem, CLOCK_MONOTONIC, 0, + &ts, NULL)); + ATF_REQUIRE_ERRNO(ETIMEDOUT, + sem_clockwait_np(&sem, CLOCK_MONOTONIC, 0, &ts, NULL)); + + /* absolute does not update remaining time on EINTR */ + struct timespec remain = {42, 1000*1000*1000}; + got_sigalrm = 0; + it.it_value.tv_usec = 50*1000; + ATF_REQUIRE_MSG(setitimer(ITIMER_REAL, &it, NULL) == 0, + "%s", strerror(errno)); + ATF_REQUIRE_MSG(clock_gettime(CLOCK_MONOTONIC, &ts) == 0, + "%s", strerror(errno)); + timespec_add_ms(&ts, 100); + ATF_REQUIRE_ERRNO(EINTR, sem_clockwait_np(&sem, CLOCK_MONOTONIC, + TIMER_ABSTIME, &ts, &remain)); + ATF_REQUIRE_MSG(got_sigalrm, "did not get SIGALRM"); + ATF_REQUIRE_MSG(remain.tv_sec == 42 && remain.tv_nsec == 1000*1000*1000, + "an absolute clockwait modified the remaining time on EINTR"); + + /* relative updates remaining time on EINTR */ + remain.tv_sec = 42; + remain.tv_nsec = 1000*1000*1000; + got_sigalrm = 0; + it.it_value.tv_usec = 50*1000; + ATF_REQUIRE_MSG(setitimer(ITIMER_REAL, &it, NULL) == 0, + "%s", strerror(errno)); + ts.tv_sec = 0; + ts.tv_nsec = 100*1000*1000; + ATF_REQUIRE_ERRNO(EINTR, sem_clockwait_np(&sem, CLOCK_MONOTONIC, 0, &ts, + &remain)); + ATF_REQUIRE_MSG(got_sigalrm, "did not get SIGALRM"); + /* + * If this nsec comparison turns out to be unreliable due to timing, + * it could simply check that nsec < 100 ms. + */ + ATF_REQUIRE_MSG(remain.tv_sec == 0 && + remain.tv_nsec >= 25*1000*1000 && + remain.tv_nsec <= 75*1000*1000, + "the remaining time was not as expected when a relative clockwait" + " got EINTR" ); +#endif +} + ATF_TP_ADD_TCS(tp) { ATF_TP_ADD_TC(tp, basic); ATF_TP_ADD_TC(tp, child); + ATF_TP_ADD_TC(tp, timedwait); return atf_no_error(); } Modified: head/include/semaphore.h ============================================================================== --- head/include/semaphore.h Thu Feb 23 19:32:25 2017 (r314178) +++ head/include/semaphore.h Thu Feb 23 19:36:38 2017 (r314179) @@ -59,6 +59,8 @@ int sem_init(sem_t *, int, unsigned int sem_t *sem_open(const char *, int, ...); int sem_post(sem_t *); int sem_timedwait(sem_t * __restrict, const struct timespec * __restrict); +int sem_clockwait_np(sem_t * __restrict, __clockid_t, int, + const struct timespec *, struct timespec *); int sem_trywait(sem_t *); int sem_unlink(const char *); int sem_wait(sem_t *); Modified: head/lib/libc/gen/Makefile.inc ============================================================================== --- head/lib/libc/gen/Makefile.inc Thu Feb 23 19:32:25 2017 (r314178) +++ head/lib/libc/gen/Makefile.inc Thu Feb 23 19:36:38 2017 (r314179) @@ -463,6 +463,7 @@ MLINKS+=scandir.3 alphasort.3 MLINKS+=sem_open.3 sem_close.3 \ sem_open.3 sem_unlink.3 MLINKS+=sem_wait.3 sem_trywait.3 +MLINKS+=sem_timedwait.3 sem_clockwait_np.3 MLINKS+=send.2 sendmmsg.2 MLINKS+=setjmp.3 _longjmp.3 \ setjmp.3 _setjmp.3 \ Modified: head/lib/libc/gen/Symbol.map ============================================================================== --- head/lib/libc/gen/Symbol.map Thu Feb 23 19:32:25 2017 (r314178) +++ head/lib/libc/gen/Symbol.map Thu Feb 23 19:36:38 2017 (r314179) @@ -415,6 +415,7 @@ FBSD_1.4 { FBSD_1.5 { basename; dirname; + sem_clockwait_np; }; FBSDprivate_1.0 { Modified: head/lib/libc/gen/sem_new.c ============================================================================== --- head/lib/libc/gen/sem_new.c Thu Feb 23 19:32:25 2017 (r314178) +++ head/lib/libc/gen/sem_new.c Thu Feb 23 19:36:38 2017 (r314179) @@ -56,6 +56,7 @@ __weak_reference(_sem_init, sem_init); __weak_reference(_sem_open, sem_open); __weak_reference(_sem_post, sem_post); __weak_reference(_sem_timedwait, sem_timedwait); +__weak_reference(_sem_clockwait_np, sem_clockwait_np); __weak_reference(_sem_trywait, sem_trywait); __weak_reference(_sem_unlink, sem_unlink); __weak_reference(_sem_wait, sem_wait); @@ -345,23 +346,34 @@ usem_wake(struct _usem2 *sem) } static __inline int -usem_wait(struct _usem2 *sem, const struct timespec *abstime) +usem_wait(struct _usem2 *sem, clockid_t clock_id, int flags, + const struct timespec *rqtp, struct timespec *rmtp) { - struct _umtx_time *tm_p, timeout; + struct { + struct _umtx_time timeout; + struct timespec remain; + } tms; + void *tm_p; size_t tm_size; + int retval; - if (abstime == NULL) { + if (rqtp == NULL) { tm_p = NULL; tm_size = 0; } else { - timeout._clockid = CLOCK_REALTIME; - timeout._flags = UMTX_ABSTIME; - timeout._timeout = *abstime; - tm_p = &timeout; - tm_size = sizeof(timeout); + tms.timeout._clockid = clock_id; + tms.timeout._flags = (flags & TIMER_ABSTIME) ? UMTX_ABSTIME : 0; + tms.timeout._timeout = *rqtp; + tm_p = &tms; + tm_size = sizeof(tms); + } + retval = _umtx_op(sem, UMTX_OP_SEM2_WAIT, 0, (void *)tm_size, tm_p); + if (retval == -1 && errno == EINTR && (flags & TIMER_ABSTIME) == 0 && + rqtp != NULL && rmtp != NULL) { + *rmtp = tms.remain; } - return _umtx_op(sem, UMTX_OP_SEM2_WAIT, 0, - (void *)tm_size, __DECONST(void*, tm_p)); + + return (retval); } int @@ -381,8 +393,8 @@ _sem_trywait(sem_t *sem) } int -_sem_timedwait(sem_t * __restrict sem, - const struct timespec * __restrict abstime) +_sem_clockwait_np(sem_t * __restrict sem, clockid_t clock_id, int flags, + const struct timespec *rqtp, struct timespec *rmtp) { int val, retval; @@ -393,7 +405,8 @@ _sem_timedwait(sem_t * __restrict sem, _pthread_testcancel(); for (;;) { while (USEM_COUNT(val = sem->_kern._count) > 0) { - if (atomic_cmpset_acq_int(&sem->_kern._count, val, val - 1)) + if (atomic_cmpset_acq_int(&sem->_kern._count, val, + val - 1)) return (0); } @@ -406,20 +419,28 @@ _sem_timedwait(sem_t * __restrict sem, * The timeout argument is only supposed to * be checked if the thread would have blocked. */ - if (abstime != NULL) { - if (abstime->tv_nsec >= 1000000000 || abstime->tv_nsec < 0) { + if (rqtp != NULL) { + if (rqtp->tv_nsec >= 1000000000 || rqtp->tv_nsec < 0) { errno = EINVAL; return (-1); } } _pthread_cancel_enter(1); - retval = usem_wait(&sem->_kern, abstime); + retval = usem_wait(&sem->_kern, clock_id, flags, rqtp, rmtp); _pthread_cancel_leave(0); } return (retval); } int +_sem_timedwait(sem_t * __restrict sem, + const struct timespec * __restrict abstime) +{ + return (_sem_clockwait_np(sem, CLOCK_REALTIME, TIMER_ABSTIME, abstime, + NULL)); +}; + +int _sem_wait(sem_t *sem) { return _sem_timedwait(sem, NULL); Modified: head/lib/libc/gen/sem_timedwait.3 ============================================================================== --- head/lib/libc/gen/sem_timedwait.3 Thu Feb 23 19:32:25 2017 (r314178) +++ head/lib/libc/gen/sem_timedwait.3 Thu Feb 23 19:36:38 2017 (r314179) @@ -34,11 +34,12 @@ .\" .\" $FreeBSD$ .\" -.Dd August 17, 2016 +.Dd February 23, 2017 .Dt SEM_TIMEDWAIT 3 .Os .Sh NAME -.Nm sem_timedwait +.Nm sem_timedwait , +.Nm sem_clockwait_np .Nd "lock a semaphore" .Sh LIBRARY .Lb libc @@ -46,6 +47,8 @@ .In semaphore.h .Ft int .Fn sem_timedwait "sem_t * restrict sem" "const struct timespec * restrict abs_timeout" +.Ft int +.Fn sem_clockwait_np "sem_t * restrict sem" "clockid_t clock_id" "int flags" "const struct timespec * rqtp" "struct timespec * rmtp" .Sh DESCRIPTION The .Fn sem_timedwait @@ -77,10 +80,40 @@ clock. The validity of the .Fa abs_timeout is not checked if the semaphore can be locked immediately. -.Sh RETURN VALUES +.Pp The -.Fn sem_timedwait -function returns zero if the calling process successfully performed the +.Fn sem_clockwait_np +function is a more flexible variant of +.Fn sem_timedwait . +The +.Fa clock_id +parameter specifies the reference clock. +If the +.Fa flags +parameter contains +.Dv TIMER_ABSTIME , +then the requested timeout +.Pq Fa rqtp +is an absolute timeout; otherwise, +the timeout is relative. +If this function fails with +.Er EINTR +and the timeout is relative, +a non-NULL +.Fa rmtp +will be updated to contain the amount of time remaining in the interval +.Po +the requested time minus the time actually slept +.Pc . +An absolute timeout has no effect on +.Fa rmtp . +A single structure can be used for both +.Fa rqtp +and +.Fa rmtp . +.Sh RETURN VALUES +These +functions return zero if the calling process successfully performed the semaphore lock operation on the semaphore designated by .Fa sem . If the call was unsuccessful, the state of the semaphore is unchanged, @@ -88,9 +121,7 @@ and the function returns a value of \-1 .Va errno to indicate the error. .Sh ERRORS -The -.Fn sem_timedwait -function will fail if: +These functions will fail if: .Bl -tag -width Er .It Bq Er EINVAL The @@ -114,6 +145,18 @@ The .Fn sem_timedwait function conforms to .St -p1003.1-2004 . +The +.Fn sem_clockwait_np +function is not specified by any standard; +it exists only on +.Fx +at the time of this writing. .Sh HISTORY -The function first appeared in +The +.Fn sem_timedwait +function first appeared in .Fx 5.0 . +The +.Fn sem_clockwait_np +function first appeared in +.Fx 12.0 . Modified: head/lib/libc/include/namespace.h ============================================================================== --- head/lib/libc/include/namespace.h Thu Feb 23 19:32:25 2017 (r314178) +++ head/lib/libc/include/namespace.h Thu Feb 23 19:36:38 2017 (r314179) @@ -217,6 +217,7 @@ #define sem_open _sem_open #define sem_post _sem_post #define sem_timedwait _sem_timedwait +#define sem_clockwait_np _sem_clockwait_np #define sem_trywait _sem_trywait #define sem_unlink _sem_unlink #define sem_wait _sem_wait Modified: head/lib/libc/include/un-namespace.h ============================================================================== --- head/lib/libc/include/un-namespace.h Thu Feb 23 19:32:25 2017 (r314178) +++ head/lib/libc/include/un-namespace.h Thu Feb 23 19:36:38 2017 (r314179) @@ -198,6 +198,7 @@ #undef sem_open #undef sem_post #undef sem_timedwait +#undef sem_clockwait_np #undef sem_trywait #undef sem_unlink #undef sem_wait Modified: head/share/man/man3/pthread_testcancel.3 ============================================================================== --- head/share/man/man3/pthread_testcancel.3 Thu Feb 23 19:32:25 2017 (r314178) +++ head/share/man/man3/pthread_testcancel.3 Thu Feb 23 19:36:38 2017 (r314179) @@ -1,5 +1,5 @@ .\" $FreeBSD$ -.Dd August 16, 2016 +.Dd February 17, 2017 .Dt PTHREAD_TESTCANCEL 3 .Os .Sh NAME @@ -120,9 +120,9 @@ is The .Fn kevent function is a cancellation point if it is potentially blocking, -i.e. when the +such as when the .Fa nevents -argument is non-zero. +argument is non-zero. .It Fn mq_receive .It Fn mq_send .It Fn mq_timedreceive @@ -146,6 +146,7 @@ argument is non-zero. .It Fn recvmsg .It Fn select .It Fn sem_timedwait +.It Fn sem_clockwait_np .It Fn sem_wait .It Fn send .It Fn sendmsg Modified: head/sys/kern/kern_umtx.c ============================================================================== --- head/sys/kern/kern_umtx.c Thu Feb 23 19:32:25 2017 (r314178) +++ head/sys/kern/kern_umtx.c Thu Feb 23 19:36:38 2017 (r314179) @@ -3219,10 +3219,16 @@ do_sem2_wait(struct thread *td, struct _ error = 0; else { umtxq_remove(uq); - /* A relative timeout cannot be restarted. */ - if (error == ERESTART && timeout != NULL && - (timeout->_flags & UMTX_ABSTIME) == 0) - error = EINTR; + if (timeout != NULL && (timeout->_flags & UMTX_ABSTIME) == 0) { + /* A relative timeout cannot be restarted. */ + if (error == ERESTART) + error = EINTR; + if (error == EINTR) { + abs_timeout_update(&timo); + timeout->_timeout = timo.end; + timespecsub(&timeout->_timeout, &timo.cur); + } + } } umtxq_unlock(&uq->uq_key); umtx_key_release(&uq->uq_key); @@ -3585,19 +3591,33 @@ static int __umtx_op_sem2_wait(struct thread *td, struct _umtx_op_args *uap) { struct _umtx_time *tm_p, timeout; + size_t uasize; int error; /* Allow a null timespec (wait forever). */ - if (uap->uaddr2 == NULL) + if (uap->uaddr2 == NULL) { + uasize = 0; tm_p = NULL; - else { - error = umtx_copyin_umtx_time( - uap->uaddr2, (size_t)uap->uaddr1, &timeout); + } else { + uasize = (size_t)uap->uaddr1; + error = umtx_copyin_umtx_time(uap->uaddr2, uasize, &timeout); if (error != 0) return (error); tm_p = &timeout; } - return (do_sem2_wait(td, uap->obj, tm_p)); + error = do_sem2_wait(td, uap->obj, tm_p); + if (error == EINTR && uap->uaddr2 != NULL && + (timeout._flags & UMTX_ABSTIME) == 0 && + uasize >= sizeof(struct _umtx_time) + sizeof(struct timespec)) { + error = copyout(&timeout._timeout, + (struct _umtx_time *)uap->uaddr2 + 1, + sizeof(struct timespec)); + if (error == 0) { + error = EINTR; + } + } + + return (error); } static int @@ -4194,19 +4214,37 @@ static int __umtx_op_sem2_wait_compat32(struct thread *td, struct _umtx_op_args *uap) { struct _umtx_time *tm_p, timeout; + size_t uasize; int error; /* Allow a null timespec (wait forever). */ - if (uap->uaddr2 == NULL) + if (uap->uaddr2 == NULL) { + uasize = 0; tm_p = NULL; - else { - error = umtx_copyin_umtx_time32(uap->uaddr2, - (size_t)uap->uaddr1, &timeout); + } else { + uasize = (size_t)uap->uaddr1; + error = umtx_copyin_umtx_time32(uap->uaddr2, uasize, &timeout); if (error != 0) return (error); tm_p = &timeout; } - return (do_sem2_wait(td, uap->obj, tm_p)); + error = do_sem2_wait(td, uap->obj, tm_p); + if (error == EINTR && uap->uaddr2 != NULL && + (timeout._flags & UMTX_ABSTIME) == 0 && + uasize >= sizeof(struct umtx_time32) + sizeof(struct timespec32)) { + struct timespec32 remain32 = { + .tv_sec = timeout._timeout.tv_sec, + .tv_nsec = timeout._timeout.tv_nsec + }; + error = copyout(&remain32, + (struct umtx_time32 *)uap->uaddr2 + 1, + sizeof(struct timespec32)); + if (error == 0) { + error = EINTR; + } + } + + return (error); } static int _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
