/* * Copyright (c) 1995 John Birrell . * All rights reserved. * * 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. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by John Birrell. * 4. Neither the name of the author nor the names of any co-contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL 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 AUTHOR 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. * * $FreeBSD$ */ /* * This module uses the magic of C++ static constructors to initialize the * threads package at program start-up time. * * Note: Because of a bug in certain versions of "/usr/lib/c++rt0.o", you * should _not_ enclose the body of this module in an "#ifdef _THREAD_SAFE" * conditional. */ extern "C" void _thread_init(void); /* * First, we declare a class with a constructor. */ class _thread_init_invoker { public: _thread_init_invoker(); /* Constructor declaration. */ }; /* * Here is the definition of the constructor. All it does is call the * threads initialization function, "_thread_init". */ _thread_init_invoker::_thread_init_invoker() { _thread_init(); } /* * Here is a single, static instance of our "_thread_init_invoker" class. * The mere existance of this instance will result in its constructor * being called, automatically, at program start-up time. */ static _thread_init_invoker the_thread_init_invoker; /* * For the shared version of the threads library, the above is sufficient. * But for the archive version of the library, we need a little bit more. * Namely, we must arrange for this particular module to be pulled in from * the archive library at link time. To accomplish that, we define and * initialize a variable, "_thread_autoinit_dummy_decl". This variable is * referenced (as an extern) from libc/stdlib/exit.c. This will always * create a need for this module, ensuring that it is present in the * executable. * * We know that, if the user does _anything_ at all with threads, then the * "uthread_init.c" module will be linked in. That is the case because * "uthread_init.c" is the module that defines all of the global variables * used by the threads library. The presence of "uthread_init.c" will, in * turn, force this module to be linked in. And the presence of this module * in the executable will result in the constructor being invoked, and * "_thread_init" being called. */ extern "C" int _thread_autoinit_dummy_decl; /* Declare with "C" linkage */ int _thread_autoinit_dummy_decl = 0;