diff options
Diffstat (limited to 'sal')
| -rw-r--r-- | sal/inc/osl/doublecheckedlocking.h | 114 | ||||
| -rw-r--r-- | sal/inc/osl/getglobalmutex.hxx | 86 |
2 files changed, 200 insertions, 0 deletions
diff --git a/sal/inc/osl/doublecheckedlocking.h b/sal/inc/osl/doublecheckedlocking.h new file mode 100644 index 000000000000..036b27846a6e --- /dev/null +++ b/sal/inc/osl/doublecheckedlocking.h @@ -0,0 +1,114 @@ +/************************************************************************* + * + * $RCSfile: doublecheckedlocking.h,v $ + * + * $Revision: 1.1 $ + * + * last change: $Author: sb $ $Date: 2002-06-24 08:29:42 $ + * + * The Contents of this file are made available subject to the terms of + * either of the following licenses + * + * - GNU Lesser General Public License Version 2.1 + * - Sun Industry Standards Source License Version 1.1 + * + * Sun Microsystems Inc., October, 2000 + * + * GNU Lesser General Public License Version 2.1 + * ============================================= + * Copyright 2000 by Sun Microsystems, Inc. + * 901 San Antonio Road, Palo Alto, CA 94303, USA + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License version 2.1, as published by the Free Software Foundation. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + * + * + * Sun Industry Standards Source License Version 1.1 + * ================================================= + * The contents of this file are subject to the Sun Industry Standards + * Source License Version 1.1 (the "License"); You may not use this file + * except in compliance with the License. You may obtain a copy of the + * License at http://www.openoffice.org/license.html. + * + * Software provided under this License is provided on an "AS IS" basis, + * WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, + * WITHOUT LIMITATION, WARRANTIES THAT THE SOFTWARE IS FREE OF DEFECTS, + * MERCHANTABLE, FIT FOR A PARTICULAR PURPOSE, OR NON-INFRINGING. + * See the License for the specific provisions governing your rights and + * obligations concerning the Software. + * + * The Initial Developer of the Original Code is: Sun Microsystems, Inc. + * + * Copyright: 2002 by Sun Microsystems, Inc. + * + * All Rights Reserved. + * + * Contributor(s): _______________________________________ + * + * + ************************************************************************/ + +#if !defined INCLUDED_OSL_DOUBLECHECKEDLOCKING_H +#define INCLUDED_OSL_DOUBLECHECKEDLOCKING_H + +#if defined __cplusplus +extern "C" { +#endif /* __cplusplus */ + +/** A platform specific macro needed to make double-checked locking work. + + See + <http://www.cs.umd.edu/~pugh/java/memoryModel/DoubleCheckedLocking.html> + for a description of double-checked locking, why it is broken, and how it + can be fixed. On platforms where it is necessary, this macro will expand + to some memory barrier instruction. On many platforms, double-checked + locking works as it is, though, so on those platforms this macro will be + empty. This is a macro instead of a (C++ inline) function to allow for + maximum performance in both C and C++. + + If possible, use the rtl_Instance template instead of explicitly spelling + out the double-checked locking pattern. There are few cases where you + will have to spell it out explicitly (e.g., the logic of a certain + instance of the pattern is too complex to be mapped to the template, or + some compiler refuses to compile a template instantiation due to internal + compiler errors), though, and you should always call this macro at the + right places then: + + static T * pInstance = 0; + + T * p = pInstance; + OSL_DOUBLE_CHECKED_LOCKING_MEMORY_BARRIER(); + if (!p) + { + Guard aGuard(aMutex); + p = pInstance; + if (!p) + { + p = ...; + OSL_DOUBLE_CHECKED_LOCKING_MEMORY_BARRIER(); + pInstance = p; + } + } + return p; + + One extra advantage of this macro is that it makes it easier to find all + places where double-checked locking is used. + */ +#define OSL_DOUBLE_CHECKED_LOCKING_MEMORY_BARRIER() /* empty */ + +#if defined __cplusplus +} +#endif /* __cplusplus */ + +#endif /* INCLUDED_OSL_DOUBLECHECKEDLOCKING_H */ diff --git a/sal/inc/osl/getglobalmutex.hxx b/sal/inc/osl/getglobalmutex.hxx new file mode 100644 index 000000000000..8dcdee8e6f2a --- /dev/null +++ b/sal/inc/osl/getglobalmutex.hxx @@ -0,0 +1,86 @@ +/************************************************************************* + * + * $RCSfile: getglobalmutex.hxx,v $ + * + * $Revision: 1.1 $ + * + * last change: $Author: sb $ $Date: 2002-06-24 08:29:42 $ + * + * The Contents of this file are made available subject to the terms of + * either of the following licenses + * + * - GNU Lesser General Public License Version 2.1 + * - Sun Industry Standards Source License Version 1.1 + * + * Sun Microsystems Inc., October, 2000 + * + * GNU Lesser General Public License Version 2.1 + * ============================================= + * Copyright 2000 by Sun Microsystems, Inc. + * 901 San Antonio Road, Palo Alto, CA 94303, USA + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License version 2.1, as published by the Free Software Foundation. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + * + * + * Sun Industry Standards Source License Version 1.1 + * ================================================= + * The contents of this file are subject to the Sun Industry Standards + * Source License Version 1.1 (the "License"); You may not use this file + * except in compliance with the License. You may obtain a copy of the + * License at http://www.openoffice.org/license.html. + * + * Software provided under this License is provided on an "AS IS" basis, + * WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, + * WITHOUT LIMITATION, WARRANTIES THAT THE SOFTWARE IS FREE OF DEFECTS, + * MERCHANTABLE, FIT FOR A PARTICULAR PURPOSE, OR NON-INFRINGING. + * See the License for the specific provisions governing your rights and + * obligations concerning the Software. + * + * The Initial Developer of the Original Code is: Sun Microsystems, Inc. + * + * Copyright: 2002 by Sun Microsystems, Inc. + * + * All Rights Reserved. + * + * Contributor(s): _______________________________________ + * + * + ************************************************************************/ + +#if !defined INCLUDED_OSL_GETGLOBALMUTEX_HXX +#define INCLUDED_OSL_GETGLOBALMUTEX_HXX + +#ifndef _OSL_MUTEX_HXX_ +#include "osl/mutex.hxx" +#endif + +namespace osl { + +/** A helper functor for the rtl_Instance template. + + See the rtl_Instance template for examples of how this class is used. + */ +class GetGlobalMutex +{ +public: + ::osl::Mutex * operator()() + { + return ::osl::Mutex::getGlobalMutex(); + } +}; + +} + +#endif // INCLUDED_OSL_GETGLOBALMUTEX_HXX |