1 /** 2 * \file 3 * \brief Atomic template 4 */ 5 /* 6 * (c) 2004-2009 Adam Lackorzynski <adam@os.inf.tu-dresden.de>, 7 * Alexander Warg <warg@os.inf.tu-dresden.de> 8 * economic rights: Technische Universität Dresden (Germany) 9 * 10 * This file is part of TUD:OS and distributed under the terms of the 11 * GNU General Public License 2. 12 * Please see the COPYING-GPL-2 file for details. 13 * 14 * As a special exception, you may use this file as part of a free software 15 * library without restriction. Specifically, if other files instantiate 16 * templates or use macros or inline functions from this file, or you compile 17 * this file and link it with other files to produce an executable, this 18 * file does not by itself cause the resulting executable to be covered by 19 * the GNU General Public License. This exception does not however 20 * invalidate any other reasons why the executable file might be covered by 21 * the GNU General Public License. 22 */ 23 #pragma once 24 25 #include <l4/util/atomic.h> 26 27 extern "C" void ____error_compare_and_swap_does_not_support_3_bytes____(); 28 extern "C" void ____error_compare_and_swap_does_not_support_more_than_4_bytes____(); 29 30 namespace L4 31 { 32 template< typename X > compare_and_swap(X volatile * dst,X old_val,X new_val)33 inline int compare_and_swap(X volatile *dst, X old_val, X new_val) 34 { 35 switch (sizeof(X)) 36 { 37 case 1: 38 return l4util_cmpxchg8((l4_uint8_t volatile*)dst, old_val, new_val); 39 case 2: 40 return l4util_cmpxchg16((l4_uint16_t volatile *)dst, old_val, new_val); 41 case 3: ____error_compare_and_swap_does_not_support_3_bytes____(); 42 case 4: 43 return l4util_cmpxchg32((l4_uint32_t volatile*)dst, old_val, new_val); 44 default: 45 ____error_compare_and_swap_does_not_support_more_than_4_bytes____(); 46 } 47 return 0; 48 } 49 } 50