/* * Copyright (c) 2010 Apple Inc. All rights reserved. * Copyright (c) 2008 Likewise Software, Inc. All rights reserved. * * @APPLE_LICENSE_HEADER_START@ * * 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. Neither the name of Apple Inc. 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IN NO EVENT SHALL APPLE OR ITS 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. * * Portions of this software have been released under the following terms: * * (c) Copyright 1989-1993 OPEN SOFTWARE FOUNDATION, INC. * (c) Copyright 1989-1993 HEWLETT-PACKARD COMPANY * (c) Copyright 1989-1993 DIGITAL EQUIPMENT CORPORATION * * To anyone who acknowledges that this file is provided "AS IS" * without any express or implied warranty: * permission to use, copy, modify, and distribute this file for any * purpose is hereby granted without fee, provided that the above * copyright notices and this notice appears in all source code copies, * and that none of the names of Open Software Foundation, Inc., Hewlett- * Packard Company or Digital Equipment Corporation be used * in advertising or publicity pertaining to distribution of the software * without specific, written prior permission. Neither Open Software * Foundation, Inc., Hewlett-Packard Company nor Digital * Equipment Corporation makes any representations about the suitability * of this software for any purpose. * * Copyright (c) 2007, Novell, Inc. 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. Neither the name of Novell Inc. nor the names of its contributors * may be used to endorse or promote products derived from this * this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT HOLDERS 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. * * @APPLE_LICENSE_HEADER_END@ */ #include <dce/dcethread.h> #include <signal.h> #include <errno.h> #include <config.h> #include "dcethread-private.h" #include "dcethread-util.h" #include "dcethread-debug.h" static void *async_signal_handler (void *dummy); /* FIXME: do we need to retain thread? */ static dcethread* thread_to_interrupt; static sigset_t async_sigset; static pthread_t helper_thread = (pthread_t)0; /* -------------------------------------------------------------------- */ /* * A S Y N C _ S I G N A L _ H A N D L E R * * This async signal handler is already running on the correct thread * stack. ALL async signals map to a "cancel". A cancel unwind happens * only at well defined points, so we can't RAISE the exception; just * post the cancel. */ static void *async_signal_handler(void *dummy ATTRIBUTE_UNUSED) { /* * Wait for and handle asynchronous signals. */ while (1) { int sig; sigwait(&async_sigset, &sig); dcethread__lock(thread_to_interrupt); dcethread__interrupt(thread_to_interrupt); dcethread__unlock(thread_to_interrupt); } return NULL; } /* * P T H R E A D _ S I G N A L _ T O _ C A N C E L _ N P * * Async signal handling consists of creating an exception package helper * thread. This helper thread will sigwait() on all async signals of * interest and will convert specific asynchronous signals (defined in the * async signal handler) to exceptions. The helper thread then posts the * cancel to the thread that initialized the exception package for * 'handling'. */ void dcethread_signal_to_interrupt(sigset_t *asigset, dcethread* thread) { /* * The helper thread will need the thread id of the first thread * to initialize the exception package. The thread that initialized * the exception package will receive a cancel when an asynchronous * signal is received. */ thread_to_interrupt = thread; async_sigset = *asigset; dcethread_lock_global(); if (helper_thread != (pthread_t)0) { pthread_cancel(helper_thread); pthread_detach(helper_thread); } /* * Create a 'helper thread' to catch aynchronous signals. */ pthread_create(&helper_thread, NULL, async_signal_handler, 0); /* * The 'helper thread' will never be joined so toss any pthread package * internal record of the thread away to conserve resources. */ pthread_detach(helper_thread); dcethread_unlock_global(); }