From owner-svn-src-all@FreeBSD.ORG Thu Feb 12 17:16:55 2015 Return-Path: Delivered-To: svn-src-all@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 401C220E; Thu, 12 Feb 2015 17:16:55 +0000 (UTC) Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:1900:2254:2068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 12040ED2; Thu, 12 Feb 2015 17:16:55 +0000 (UTC) Received: from svn.freebsd.org ([127.0.1.70]) by svn.freebsd.org (8.14.9/8.14.9) with ESMTP id t1CHGsiA092510; Thu, 12 Feb 2015 17:16:54 GMT (envelope-from kib@FreeBSD.org) Received: (from kib@localhost) by svn.freebsd.org (8.14.9/8.14.9/Submit) id t1CHGsbm092509; Thu, 12 Feb 2015 17:16:54 GMT (envelope-from kib@FreeBSD.org) Message-Id: <201502121716.t1CHGsbm092509@svn.freebsd.org> X-Authentication-Warning: svn.freebsd.org: kib set sender to kib@FreeBSD.org using -f From: Konstantin Belousov Date: Thu, 12 Feb 2015 17:16:54 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r278627 - head/lib/libthr X-SVN-Group: head MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 12 Feb 2015 17:16:55 -0000 Author: kib Date: Thu Feb 12 17:16:54 2015 New Revision: 278627 URL: https://svnweb.freebsd.org/changeset/base/278627 Log: Update libthr(3) man page to reflect the work done to support dlopen. Noted and reviewed by: bdrewery Sponsored by: The FreeBSD Foundation MFC after: 1 week Modified: head/lib/libthr/libthr.3 Modified: head/lib/libthr/libthr.3 ============================================================================== --- head/lib/libthr/libthr.3 Thu Feb 12 17:01:54 2015 (r278626) +++ head/lib/libthr/libthr.3 Thu Feb 12 17:16:54 2015 (r278627) @@ -1,5 +1,5 @@ .\" Copyright (c) 2005 Robert N. M. Watson -.\" Copyright (c) 2014 The FreeBSD Foundation, Inc. +.\" Copyright (c) 2014,2015 The FreeBSD Foundation, Inc. .\" All rights reserved. .\" .\" Part of this documentation was written by @@ -29,7 +29,7 @@ .\" .\" $FreeBSD$ .\" -.Dd September 26, 2014 +.Dd February 12, 2015 .Dt LIBTHR 3 .Os .Sh NAME @@ -200,45 +200,25 @@ Bigger values reduce the frequency of th The value must be between 0 and 255. .El .Sh INTERACTION WITH RUN-TIME LINKER -The +On load, .Nm -library must appear before -.Li libc -in the global order of depended objects. -.Pp -Loading -.Nm -with the -.Xr dlopen 3 -call in the process after the program binary is activated -is not supported, and causes miscellaneous and hard-to-diagnose misbehaviour. -This is due to -.Nm -interposing several important -.Li libc -symbols to provide thread-safe services. -In particular, -.Dv errno -and the locking stubs from -.Li libc -are affected. -This requirement is currently not enforced. -.Pp -If the program loads any modules at run-time, and those modules may require -threading services, the main program binary must be linked with -.Li libpthread , -even if it does not require any services from the library. +installs interposing handlers into the hooks exported by +.Li libc . +The interposers provide real locking implementation instead of the +stubs for single-threaded processes in +.Li , +cancellation support and some modifications to the signal operations. .Pp .Nm cannot be unloaded; the .Xr dlclose 3 function does not perform any action when called with a handle for .Nm . -One of the reasons is that the interposing of +One of the reasons is that the internal interposing of .Li libc functions cannot be undone. .Sh SIGNALS -The implementation also interposes the user-installed +The implementation interposes the user-installed .Xr signal 3 handlers. This interposing is done to postpone signal delivery to threads which