Date: Sun, 12 Apr 2015 06:52:44 +0000 (UTC) From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-10@freebsd.org Subject: svn commit: r281454 - in stable/10: lib/libc/include lib/libc/sys lib/libthr/thread share/man/man3 Message-ID: <201504120652.t3C6qiYV009568@svn.freebsd.org>
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Author: kib Date: Sun Apr 12 06:52:43 2015 New Revision: 281454 URL: https://svnweb.freebsd.org/changeset/base/281454 Log: MFC r280818: Make kevent(2) a cancellation point. Added: stable/10/lib/libc/sys/kevent.c - copied unchanged from r280818, head/lib/libc/sys/kevent.c Modified: stable/10/lib/libc/include/libc_private.h stable/10/lib/libc/sys/Makefile.inc stable/10/lib/libc/sys/interposing_table.c stable/10/lib/libc/sys/kqueue.2 stable/10/lib/libthr/thread/thr_syscalls.c stable/10/share/man/man3/pthread_testcancel.3 Directory Properties: stable/10/ (props changed) Modified: stable/10/lib/libc/include/libc_private.h ============================================================================== --- stable/10/lib/libc/include/libc_private.h Sun Apr 12 06:45:40 2015 (r281453) +++ stable/10/lib/libc/include/libc_private.h Sun Apr 12 06:52:43 2015 (r281454) @@ -221,6 +221,7 @@ enum { INTERPOS__pthread_mutex_init_calloc_cb, INTERPOS_spinlock, INTERPOS_spinunlock, + INTERPOS_kevent, INTERPOS_MAX }; @@ -293,6 +294,7 @@ void * __sys_freebsd6_mmap(void *, __siz struct aiocb; struct fd_set; struct iovec; +struct kevent; struct msghdr; struct pollfd; struct rusage; @@ -315,6 +317,8 @@ int __sys_fsync(int); __pid_t __sys_fork(void); int __sys_ftruncate(int, __off_t); int __sys_gettimeofday(struct timeval *, struct timezone *); +int __sys_kevent(int, const struct kevent *, int, struct kevent *, + int, const struct timespec *); __off_t __sys_lseek(int, __off_t, int); void *__sys_mmap(void *, __size_t, int, int, int, __off_t); int __sys_msync(void *, __size_t, int); Modified: stable/10/lib/libc/sys/Makefile.inc ============================================================================== --- stable/10/lib/libc/sys/Makefile.inc Sun Apr 12 06:45:40 2015 (r281453) +++ stable/10/lib/libc/sys/Makefile.inc Sun Apr 12 06:52:43 2015 (r281454) @@ -47,6 +47,7 @@ INTERPOSED = \ fcntl \ fsync \ fork \ + kevent \ msync \ nanosleep \ open \ Modified: stable/10/lib/libc/sys/interposing_table.c ============================================================================== --- stable/10/lib/libc/sys/interposing_table.c Sun Apr 12 06:45:40 2015 (r281453) +++ stable/10/lib/libc/sys/interposing_table.c Sun Apr 12 06:52:43 2015 (r281454) @@ -75,6 +75,7 @@ interpos_func_t __libc_interposing[INTER SLOT(_pthread_mutex_init_calloc_cb, _pthread_mutex_init_calloc_cb_stub), SLOT(spinlock, __libc_spinlock_stub), SLOT(spinunlock, __libc_spinunlock_stub), + SLOT(kevent, __sys_kevent), }; #undef SLOT Copied: stable/10/lib/libc/sys/kevent.c (from r280818, head/lib/libc/sys/kevent.c) ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ stable/10/lib/libc/sys/kevent.c Sun Apr 12 06:52:43 2015 (r281454, copy of r280818, head/lib/libc/sys/kevent.c) @@ -0,0 +1,53 @@ +/* + * Copyright (c) 2015 The FreeBSD Foundation. + * All rights reserved. + * + * Portions of this software were developed by Konstantin Belousov + * under sponsorship from the FreeBSD Foundation. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice(s), this list of conditions and the following disclaimer as + * the first lines of this file unmodified other than the possible + * addition of one or more copyright notices. + * 2. Redistributions in binary form must reproduce the above copyright + * notice(s), this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY + * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR + * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR + * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, + * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE + * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, + * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include <sys/types.h> +#include <sys/event.h> +#include <sys/time.h> +#include "libc_private.h" + +__weak_reference(__sys_kevent, __kevent); + +#pragma weak kevent +int +kevent(int kq, const struct kevent *changelist, int nchanges, + struct kevent *eventlist, int nevents, const struct timespec *timeout) +{ + + return (((int (*)(int, const struct kevent *, int, + struct kevent *, int, const struct timespec *)) + __libc_interposing[INTERPOS_kevent])(kq, changelist, nchanges, + eventlist, nevents, timeout)); +} Modified: stable/10/lib/libc/sys/kqueue.2 ============================================================================== --- stable/10/lib/libc/sys/kqueue.2 Sun Apr 12 06:45:40 2015 (r281453) +++ stable/10/lib/libc/sys/kqueue.2 Sun Apr 12 06:52:43 2015 (r281454) @@ -24,7 +24,7 @@ .\" .\" $FreeBSD$ .\" -.Dd July 18, 2014 +.Dd March 29, 2015 .Dt KQUEUE 2 .Os .Sh NAME @@ -41,7 +41,7 @@ .Fn kqueue "void" .Ft int .Fn kevent "int kq" "const struct kevent *changelist" "int nchanges" "struct kevent *eventlist" "int nevents" "const struct timespec *timeout" -.Fn EV_SET "&kev" ident filter flags fflags data udata +.Fn EV_SET "kev" ident filter flags fflags data udata .Sh DESCRIPTION The .Fn kqueue @@ -532,6 +532,16 @@ On return, .Va fflags contains the users defined flags in the lower 24 bits. .El +.Sh CANCELLATION BEHAVIOUR +If +.Fa nevents +is non-zero, i.e. the function is potentially blocking, the call +is a cancellation point. +Otherwise, i.e. if +.Fa nevents +is zero, the call is not cancellable. +Cancellation can only occur before any changes are made to the kqueue, +or when the call was blocked and no changes to the queue were requested. .Sh RETURN VALUES The .Fn kqueue @@ -595,6 +605,8 @@ The specified descriptor is invalid. .It Bq Er EINTR A signal was delivered before the timeout expired and before any events were placed on the kqueue for return. +.It Bq Er EINTR +A cancellation request was delivered to the thread, but not yet handled. .It Bq Er EINVAL The specified time limit or filter is invalid. .It Bq Er ENOENT @@ -609,6 +621,14 @@ sysctl. .It Bq Er ESRCH The specified process to attach to does not exist. .El +.Pp +When +.Fn kevent +call fails with +.Er EINTR +error, all changes in the +.Fa changelist +have been applied. .Sh SEE ALSO .Xr aio_error 2 , .Xr aio_read 2 , @@ -618,6 +638,7 @@ The specified process to attach to does .Xr select 2 , .Xr sigaction 2 , .Xr write 2 , +.Xr pthread_setcancelstate 3 , .Xr signal 3 .Sh HISTORY The Modified: stable/10/lib/libthr/thread/thr_syscalls.c ============================================================================== --- stable/10/lib/libthr/thread/thr_syscalls.c Sun Apr 12 06:45:40 2015 (r281453) +++ stable/10/lib/libthr/thread/thr_syscalls.c Sun Apr 12 06:52:43 2015 (r281454) @@ -341,6 +341,29 @@ __thr_pselect(int count, fd_set *rfds, f return (ret); } +static int +__thr_kevent(int kq, const struct kevent *changelist, int nchanges, + struct kevent *eventlist, int nevents, const struct timespec *timeout) +{ + struct pthread *curthread; + int ret; + + if (nevents == 0) { + /* + * No blocking, do not make the call cancellable. + */ + return (__sys_kevent(kq, changelist, nchanges, eventlist, + nevents, timeout)); + } + curthread = _get_curthread(); + _thr_cancel_enter(curthread); + ret = __sys_kevent(kq, changelist, nchanges, eventlist, nevents, + timeout); + _thr_cancel_leave(curthread, ret == -1 && nchanges == 0); + + return (ret); +} + /* * Cancellation behavior: * Thread may be canceled at start, but if the system call got some data, @@ -599,6 +622,7 @@ __thr_interpose_libc(void) SLOT(writev); SLOT(spinlock); SLOT(spinunlock); + SLOT(kevent); #undef SLOT *(__libc_interposing_slot( INTERPOS__pthread_mutex_init_calloc_cb)) = Modified: stable/10/share/man/man3/pthread_testcancel.3 ============================================================================== --- stable/10/share/man/man3/pthread_testcancel.3 Sun Apr 12 06:45:40 2015 (r281453) +++ stable/10/share/man/man3/pthread_testcancel.3 Sun Apr 12 06:52:43 2015 (r281454) @@ -1,5 +1,5 @@ .\" $FreeBSD$ -.Dd June 11, 2013 +.Dd March 29, 2015 .Dt PTHREAD_TESTCANCEL 3 .Os .Sh NAME @@ -107,6 +107,7 @@ functions: .Fn close , .Fn creat , .Fn fsync , +.Fn kevent , .Fn mq_receive , .Fn mq_send , .Fn mq_timedreceive , @@ -147,12 +148,20 @@ functions: .Fn waitpid , .Fn write , .Fn writev . +.Pp The .Fn fcntl function is a cancellation point if .Fa cmd is .Dv F_SETLKW . +.Pp +The +.Fn kevent +function is a cancellation point if it is potentially blocking, +i.e. when the +.Fa nevents +argument is non-zero. .Sh RETURN VALUES If successful, the .Fn pthread_setcancelstate
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