svn commit: r306625 - stable/11/lib/libc/sys

Mon Oct 3 09:30:27 UTC 2016

Author: kib
Date: Mon Oct  3 09:30:25 2016
New Revision: 306625
URL: https://svnweb.freebsd.org/changeset/base/306625

Log:
  MFC r306334:
  Document thr_suspend(2) and thr_wake(2).
  
  MFC r306506:
  Reword the statement.

Added:
  stable/11/lib/libc/sys/thr_suspend.2
     - copied, changed from r306334, head/lib/libc/sys/thr_suspend.2
  stable/11/lib/libc/sys/thr_wake.2
     - copied unchanged from r306334, head/lib/libc/sys/thr_wake.2
Modified:
  stable/11/lib/libc/sys/Makefile.inc
Directory Properties:
  stable/11/   (props changed)

Modified: stable/11/lib/libc/sys/Makefile.inc
==============================================================================

--- stable/11/lib/libc/sys/Makefile.inc	Mon Oct  3 09:28:06 2016	(r306624)
+++ stable/11/lib/libc/sys/Makefile.inc	Mon Oct  3 09:30:25 2016	(r306625)
@@ -311,6 +311,8 @@ MAN+=	sctp_generic_recvmsg.2 \
 	thr_new.2 \
 	thr_self.2 \
 	thr_set_name.2 \
+	thr_suspend.2 \
+	thr_wake.2 \
 	timer_create.2 \
 	timer_delete.2 \
 	timer_settime.2 \

Copied and modified: stable/11/lib/libc/sys/thr_suspend.2 (from r306334, head/lib/libc/sys/thr_suspend.2)
==============================================================================
--- head/lib/libc/sys/thr_suspend.2	Mon Sep 26 08:18:34 2016	(r306334, copy source)
+++ stable/11/lib/libc/sys/thr_suspend.2	Mon Oct  3 09:30:25 2016	(r306625)
@@ -61,9 +61,9 @@ system call puts the calling thread in a
 not eligible for CPU time.
 This state is exited by another thread calling
 .Xr thr_wake 2 ,
-by expiration of the timeout specified in the
+when the time interval specified by
 .Fa timeout
-argument,
+has elapsed,
 or by the delivery of a signal to the suspended thread.
 .Pp
 If the

Copied: stable/11/lib/libc/sys/thr_wake.2 (from r306334, head/lib/libc/sys/thr_wake.2)
==============================================================================
--- /dev/null	00:00:00 1970	(empty, because file is newly added)
+++ stable/11/lib/libc/sys/thr_wake.2	Mon Oct  3 09:30:25 2016	(r306625, copy of r306334, head/lib/libc/sys/thr_wake.2)
@@ -0,0 +1,112 @@
+.\" Copyright (c) 2016 The FreeBSD Foundation, Inc.
+.\" All rights reserved.
+.\"
+.\" This documentation was written by
+.\" Konstantin Belousov <kib at FreeBSD.org> 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, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, 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 AUTHORS AND CONTRIBUTORS ``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 AUTHORS OR CONTRIBUTORS 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.
+.\"
+.\" $FreeBSD$
+.\"
+.Dd September 23, 2016
+.Dt THR_WAKE 2
+.Os
+.Sh NAME
+.Nm thr_wake
+.Nd wake up the suspended thread
+.Sh LIBRARY
+.Lb libc
+.Sh SYNOPSIS
+.In sys/thr.h
+.Ft int
+.Fn thr_wake "long id"
+.Sh DESCRIPTION
+.Bf -symbolic
+This function is intended for implementing threading.
+Normal applications should use
+.Xr pthread_cond_timedwait 3
+together with
+.Xr pthread_cond_broadcast 3
+for typical safe suspension with cooperation of the thread
+being suspended, or
+.Xr pthread_suspend_np 3
+and
+.Xr pthread_resume_np 3
+in some specific situations, instead.
+.Ef
+.Pp
+Passing the thread identifier of the calling thread
+.Po
+see
+.Xr thr_self 2
+.Pc
+to
+.Fn thr_wake
+sets a thread's flag to cause the next signal-interruptible sleep
+of that thread in the kernel to fail immediately with the
+.Er EINTR
+error.
+The flag is cleared by an interruptible sleep attempt or by a call to
+.Xr thr_suspend 2.
+This is used by the system threading library to implement cancellation.
+.Pp
+If
+.Fa id
+is not equal to the current thread identifier, the specified thread is
+woken up if suspended by the
+.Xr thr_suspend
+system call.
+If the thread is not suspended at the time of the
+.Nm
+call, the wake is remembered and the next attempt of the thread to
+suspend itself with the
+.Xr thr_suspend 2
+results in immediate return with success.
+Only one wake is remembered.
+.Sh RETURN VALUES
+.Rv -std thr_wake
+.Sh ERRORS
+The
+.Fn thr_wake
+operation returns these errors:
+.Bl -tag -width Er
+.It Bq Er ESRCH
+The specified thread was not found or does not belong to the process
+of the calling thread.
+.El
+.Sh SEE ALSO
+.Xr ps 1 ,
+.Xr thr_self 2
+.Xr thr_suspend 2 ,
+.Xr pthread_cancel 3 ,
+.Xr pthread_resume_np 3 ,
+.Xr pthread_suspend_np 3
+.Sh STANDARDS
+The
+.Fn thr_suspend
+system call is non-standard and is used by
+.Lb libthr
+to implement
+.St -p1003.1-2001
+.Xr pthread 3
+functionality.
