/* * pthread_mutexattr_settype.c * * Description: * This translation unit implements mutual exclusion (mutex) primitives. * * -------------------------------------------------------------------------- * * Pthreads-win32 - POSIX Threads Library for Win32 * Copyright(C) 1998 John E. Bossom * Copyright(C) 1999,2005 Pthreads-win32 contributors * * Contact Email: rpj@callisto.canberra.edu.au * * The current list of contributors is contained * in the file CONTRIBUTORS included with the source * code distribution. The list can also be seen at the * following World Wide Web location: * http://sources.redhat.com/pthreads-win32/contributors.html * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * 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 in the file COPYING.LIB; * if not, write to the Free Software Foundation, Inc., * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA */ #include "pthread.h" #include "implement.h" int pthread_mutexattr_settype (pthread_mutexattr_t * attr, int kind) /* * ------------------------------------------------------ * * DOCPUBLIC * The pthread_mutexattr_settype() and * pthread_mutexattr_gettype() functions respectively set and * get the mutex type attribute. This attribute is set in the * type parameter to these functions. * * PARAMETERS * attr * pointer to an instance of pthread_mutexattr_t * * type * must be one of: * * PTHREAD_MUTEX_DEFAULT * * PTHREAD_MUTEX_NORMAL * * PTHREAD_MUTEX_ERRORCHECK * * PTHREAD_MUTEX_RECURSIVE * * DESCRIPTION * The pthread_mutexattr_settype() and * pthread_mutexattr_gettype() functions respectively set and * get the mutex type attribute. This attribute is set in the * type parameter to these functions. The default value of the * type attribute is PTHREAD_MUTEX_DEFAULT. * * The type of mutex is contained in the type attribute of the * mutex attributes. Valid mutex types include: * * PTHREAD_MUTEX_NORMAL * This type of mutex does not detect deadlock. A * thread attempting to relock this mutex without * first unlocking it will deadlock. Attempting to * unlock a mutex locked by a different thread * results in undefined behavior. Attempting to * unlock an unlocked mutex results in undefined * behavior. * * PTHREAD_MUTEX_ERRORCHECK * This type of mutex provides error checking. A * thread attempting to relock this mutex without * first unlocking it will return with an error. A * thread attempting to unlock a mutex which another * thread has locked will return with an error. A * thread attempting to unlock an unlocked mutex will * return with an error. * * PTHREAD_MUTEX_DEFAULT * Same as PTHREAD_MUTEX_NORMAL. * * PTHREAD_MUTEX_RECURSIVE * A thread attempting to relock this mutex without * first unlocking it will succeed in locking the * mutex. The relocking deadlock which can occur with * mutexes of type PTHREAD_MUTEX_NORMAL cannot occur * with this type of mutex. Multiple locks of this * mutex require the same number of unlocks to * release the mutex before another thread can * acquire the mutex. A thread attempting to unlock a * mutex which another thread has locked will return * with an error. A thread attempting to unlock an * unlocked mutex will return with an error. This * type of mutex is only supported for mutexes whose * process shared attribute is * PTHREAD_PROCESS_PRIVATE. * * RESULTS * 0 successfully set attribute, * EINVAL 'attr' or 'type' is invalid, * * ------------------------------------------------------ */ { int result = 0; if ((attr != NULL && *attr != NULL)) { switch (kind) { case PTHREAD_MUTEX_FAST_NP: case PTHREAD_MUTEX_RECURSIVE_NP: case PTHREAD_MUTEX_ERRORCHECK_NP: (*attr)->kind = kind; break; default: result = EINVAL; break; } } else { result = EINVAL; } return (result); } /* pthread_mutexattr_settype */