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glibc  2.9
malloc-machine.h
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00001 /* Basic platform-independent macro definitions for mutexes,
00002    thread-specific data and parameters for malloc.
00003    Copyright (C) 2003 Free Software Foundation, Inc.
00004    This file is part of the GNU C Library.
00005 
00006    The GNU C Library is free software; you can redistribute it and/or
00007    modify it under the terms of the GNU Lesser General Public
00008    License as published by the Free Software Foundation; either
00009    version 2.1 of the License, or (at your option) any later version.
00010 
00011    The GNU C Library is distributed in the hope that it will be useful,
00012    but WITHOUT ANY WARRANTY; without even the implied warranty of
00013    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00014    Lesser General Public License for more details.
00015 
00016    You should have received a copy of the GNU Lesser General Public
00017    License along with the GNU C Library; if not, write to the Free
00018    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
00019    02111-1307 USA.  */
00020 
00021 #ifndef _GENERIC_MALLOC_MACHINE_H
00022 #define _GENERIC_MALLOC_MACHINE_H
00023 
00024 #include <atomic.h>
00025 
00026 #ifndef mutex_init /* No threads, provide dummy macros */
00027 
00028 # define NO_THREADS
00029 
00030 /* The mutex functions used to do absolutely nothing, i.e. lock,
00031    trylock and unlock would always just return 0.  However, even
00032    without any concurrently active threads, a mutex can be used
00033    legitimately as an `in use' flag.  To make the code that is
00034    protected by a mutex async-signal safe, these macros would have to
00035    be based on atomic test-and-set operations, for example. */
00036 typedef int mutex_t;
00037 
00038 # define mutex_init(m)              (*(m) = 0)
00039 # define mutex_lock(m)              ((*(m) = 1), 0)
00040 # define mutex_trylock(m)           (*(m) ? 1 : ((*(m) = 1), 0))
00041 # define mutex_unlock(m)            (*(m) = 0)
00042 
00043 typedef void *tsd_key_t;
00044 # define tsd_key_create(key, destr) do {} while(0)
00045 # define tsd_setspecific(key, data) ((key) = (data))
00046 # define tsd_getspecific(key, vptr) (vptr = (key))
00047 
00048 # define thread_atfork(prepare, parent, child) do {} while(0)
00049 
00050 #endif /* !defined mutex_init */
00051 
00052 #ifndef atomic_full_barrier
00053 # define atomic_full_barrier() __asm ("" ::: "memory")
00054 #endif
00055 
00056 #ifndef atomic_read_barrier
00057 # define atomic_read_barrier() atomic_full_barrier ()
00058 #endif
00059 
00060 #ifndef atomic_write_barrier
00061 # define atomic_write_barrier() atomic_full_barrier ()
00062 #endif
00063 
00064 #ifndef DEFAULT_TOP_PAD
00065 # define DEFAULT_TOP_PAD 131072
00066 #endif
00067 
00068 #endif /* !defined(_GENERIC_MALLOC_MACHINE_H) */