1 /* Basic platform-independent macro definitions for mutexes, 2 thread-specific data and parameters for malloc. 3 Copyright (C) 2003 Free Software Foundation, Inc. 4 This file is part of the GNU C Library. 5 6 The GNU C Library is free software; you can redistribute it and/or 7 modify it under the terms of the GNU Lesser General Public 8 License as published by the Free Software Foundation; either 9 version 2.1 of the License, or (at your option) any later version. 10 11 The GNU C Library is distributed in the hope that it will be useful, 12 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 Lesser General Public License for more details. 15 16 You should have received a copy of the GNU Lesser General Public 17 License along with the GNU C Library; if not, write to the Free 18 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 19 02111-1307 USA. */ 20 21 #ifndef _GENERIC_MALLOC_MACHINE_H 22 #define _GENERIC_MALLOC_MACHINE_H 23 24 #include <atomic.h> 25 26 #ifndef mutex_init /* No threads, provide dummy macros */ 27 28 # define NO_THREADS 29 30 /* The mutex functions used to do absolutely nothing, i.e. lock, 31 trylock and unlock would always just return 0. However, even 32 without any concurrently active threads, a mutex can be used 33 legitimately as an `in use' flag. To make the code that is 34 protected by a mutex async-signal safe, these macros would have to 35 be based on atomic test-and-set operations, for example. */ 36 typedef int mutex_t; 37 38 # define mutex_init(m) (*(m) = 0) 39 # define mutex_lock(m) ((*(m) = 1), 0) 40 # define mutex_trylock(m) (*(m) ? 1 : ((*(m) = 1), 0)) 41 # define mutex_unlock(m) (*(m) = 0) 42 43 typedef void *tsd_key_t; 44 # define tsd_key_create(key, destr) do {} while(0) 45 # define tsd_setspecific(key, data) ((key) = (data)) 46 # define tsd_getspecific(key, vptr) (vptr = (key)) 47 48 # define thread_atfork(prepare, parent, child) do {} while(0) 49 50 #endif /* !defined mutex_init */ 51 52 #ifndef atomic_full_barrier 53 # define atomic_full_barrier() __asm ("" ::: "memory") 54 #endif 55 56 #ifndef atomic_read_barrier 57 # define atomic_read_barrier() atomic_full_barrier () 58 #endif 59 60 #ifndef atomic_write_barrier 61 # define atomic_write_barrier() atomic_full_barrier () 62 #endif 63 64 #ifndef DEFAULT_TOP_PAD 65 # define DEFAULT_TOP_PAD 131072 66 #endif 67 68 #endif /* !defined(_GENERIC_MALLOC_MACHINE_H) */ 69