cairo/src/cairo-mutex-impl-private.h

   1 /* cairo - a vector graphics library with display and print output
   2  *
   3  * Copyright © 2002 University of Southern California
   4  * Copyright © 2005,2007 Red Hat, Inc.
   5  * Copyright © 2007 Mathias Hasselmann
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it either under the terms of the GNU Lesser General Public
   9  * License version 2.1 as published by the Free Software Foundation
  10  * (the "LGPL") or, at your option, under the terms of the Mozilla
  11  * Public License Version 1.1 (the "MPL"). If you do not alter this
  12  * notice, a recipient may use your version of this file under either
  13  * the MPL or the LGPL.
  14  *
  15  * You should have received a copy of the LGPL along with this library
  16  * in the file COPYING-LGPL-2.1; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  18  * You should have received a copy of the MPL along with this library
  19  * in the file COPYING-MPL-1.1
  20  *
  21  * The contents of this file are subject to the Mozilla Public License
  22  * Version 1.1 (the "License"); you may not use this file except in
  23  * compliance with the License. You may obtain a copy of the License at
  24  * http://www.mozilla.org/MPL/
  25  *
  26  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
  27  * OF ANY KIND, either express or implied. See the LGPL or the MPL for
  28  * the specific language governing rights and limitations.
  29  *
  30  * The Original Code is the cairo graphics library.
  31  *
  32  * The Initial Developer of the Original Code is University of Southern
  33  * California.
  34  *
  35  * Contributor(s):
  36  *      Carl D. Worth <cworth@cworth.org>
  37  *      Mathias Hasselmann <mathias.hasselmann@gmx.de>
  38  *      Behdad Esfahbod <behdad@behdad.org>
  39  */
  40
  41 #ifndef CAIRO_MUTEX_IMPL_PRIVATE_H
  42 #define CAIRO_MUTEX_IMPL_PRIVATE_H
  43
  44 #include "cairo.h"
  45
  46 #if HAVE_CONFIG_H
  47 #include "config.h"
  48 #endif
  49
  50 #if HAVE_LOCKDEP
  51 #include <lockdep.h>
  52 #endif
  53
  54 /* A fully qualified no-operation statement */
  55 #define CAIRO_MUTEX_IMPL_NOOP   do {/*no-op*/} while (0)
  56 /* And one that evaluates it's argument once */
  57 #define CAIRO_MUTEX_IMPL_NOOP1(expr)        do { if (expr) ; } while (0)
  58
  59
  60 /* Cairo mutex implementation:
  61  *
  62  * Any new mutex implementation needs to do the following:
  63  *
  64  * - Condition on the right header or feature.  Headers are
  65  *   preferred as eg. you still can use win32 mutex implementation
  66  *   on a win32 system even if you do not compile the win32
  67  *   surface/backend.
  68  *
  69  * - typedef #cairo_mutex_impl_t to the proper mutex type on your target
  70  *   system.  Note that you may or may not need to use a pointer,
  71  *   depending on what kinds of initialization your mutex
  72  *   implementation supports.  No trailing semicolon needed.
  73  *   You should be able to compile the following snippet (don't try
  74  *   running it):
  75  *
  76  *   <programlisting>
  77  *      cairo_mutex_impl_t _cairo_some_mutex;
  78  *   </programlisting>
  79  *
  80  * - #define %CAIRO_MUTEX_IMPL_<NAME> 1 with suitable name for your platform.  You
  81  *   can later use this symbol in cairo-system.c.
  82  *
  83  * - #define CAIRO_MUTEX_IMPL_LOCK(mutex) and CAIRO_MUTEX_IMPL_UNLOCK(mutex) to
  84  *   proper statement to lock/unlock the mutex object passed in.
  85  *   You can (and should) assume that the mutex is already
  86  *   initialized, and is-not-already-locked/is-locked,
  87  *   respectively.  Use the "do { ... } while (0)" idiom if necessary.
  88  *   No trailing semicolons are needed (in any macro you define here).
  89  *   You should be able to compile the following snippet:
  90  *
  91  *   <programlisting>
  92  *      cairo_mutex_impl_t _cairo_some_mutex;
  93  *
  94  *      if (1)
  95  *          CAIRO_MUTEX_IMPL_LOCK (_cairo_some_mutex);
  96  *      else
  97  *          CAIRO_MUTEX_IMPL_UNLOCK (_cairo_some_mutex);
  98  *   </programlisting>
  99  *
 100  * - #define %CAIRO_MUTEX_IMPL_NIL_INITIALIZER to something that can
 101  *   initialize the #cairo_mutex_impl_t type you defined.  Most of the
 102  *   time one of 0, %NULL, or {} works.  At this point
 103  *   you should be able to compile the following snippet:
 104  *
 105  *   <programlisting>
 106  *      cairo_mutex_impl_t _cairo_some_mutex = CAIRO_MUTEX_IMPL_NIL_INITIALIZER;
 107  *
 108  *      if (1)
 109  *          CAIRO_MUTEX_IMPL_LOCK (_cairo_some_mutex);
 110  *      else
 111  *          CAIRO_MUTEX_IMPL_UNLOCK (_cairo_some_mutex);
 112  *   </programlisting>
 113  *
 114  * - If the above code is not enough to initialize a mutex on
 115  *   your platform, #define CAIRO_MUTEX_IMPL_INIT(mutex) to statement
 116  *   to initialize the mutex (allocate resources, etc).  Such that
 117  *   you should be able to compile AND RUN the following snippet:
 118  *
 119  *   <programlisting>
 120  *      cairo_mutex_impl_t _cairo_some_mutex = CAIRO_MUTEX_IMPL_NIL_INITIALIZER;
 121  *
 122  *      CAIRO_MUTEX_IMPL_INIT (_cairo_some_mutex);
 123  *
 124  *      if (1)
 125  *          CAIRO_MUTEX_IMPL_LOCK (_cairo_some_mutex);
 126  *      else
 127  *          CAIRO_MUTEX_IMPL_UNLOCK (_cairo_some_mutex);
 128  *   </programlisting>
 129  *
 130  * - If you define CAIRO_MUTEX_IMPL_INIT(mutex), cairo will use it to
 131  *   initialize all static mutex'es.  If for any reason that should
 132  *   not happen (eg. %CAIRO_MUTEX_IMPL_INIT is just a faster way than
 133  *   what cairo does using %CAIRO_MUTEX_IMPL_NIL_INITIALIZER), then
 134  *   <programlisting>
 135  *      #define CAIRO_MUTEX_IMPL_INITIALIZE() CAIRO_MUTEX_IMPL_NOOP
 136  *   </programlisting>
 137  *
 138  * - If your system supports freeing a mutex object (deallocating
 139  *   resources, etc), then #define CAIRO_MUTEX_IMPL_FINI(mutex) to do
 140  *   that.
 141  *
 142  * - If you define CAIRO_MUTEX_IMPL_FINI(mutex), cairo will use it to
 143  *   define a finalizer function to finalize all static mutex'es.
 144  *   However, it's up to you to call CAIRO_MUTEX_IMPL_FINALIZE() at
 145  *   proper places, eg. when the system is unloading the cairo library.
 146  *   So, if for any reason finalizing static mutex'es is not needed
 147  *   (eg. you never call CAIRO_MUTEX_IMPL_FINALIZE()), then
 148  *   <programlisting>
 149  *      #define CAIRO_MUTEX_IMPL_FINALIZE() CAIRO_MUTEX_IMPL_NOOP
 150  *   </programlisting>
 151  *
 152  * - That is all.  If for any reason you think the above API is
 153  *   not enough to implement #cairo_mutex_impl_t on your system, please
 154  *   stop and write to the cairo mailing list about it.  DO NOT
 155  *   poke around cairo-mutex-private.h for possible solutions.
 156  */
 157
 158 #if CAIRO_NO_MUTEX
 159
 160 /* No mutexes */
 161
 162   typedef int cairo_mutex_impl_t;
 163
 164 # define CAIRO_MUTEX_IMPL_NO 1
 165 # define CAIRO_MUTEX_IMPL_INITIALIZE() CAIRO_MUTEX_IMPL_NOOP
 166 # define CAIRO_MUTEX_IMPL_LOCK(mutex) CAIRO_MUTEX_IMPL_NOOP1(mutex)
 167 # define CAIRO_MUTEX_IMPL_UNLOCK(mutex) CAIRO_MUTEX_IMPL_NOOP1(mutex)
 168 # define CAIRO_MUTEX_IMPL_NIL_INITIALIZER 0
 169
 170 #elif HAVE_PTHREAD_H /*******************************************************/
 171
 172 # include <pthread.h>
 173
 174   typedef pthread_mutex_t cairo_mutex_impl_t;
 175
 176 # define CAIRO_MUTEX_IMPL_PTHREAD 1
 177 #if HAVE_LOCKDEP
 178 /* expose all mutexes to the validator */
 179 # define CAIRO_MUTEX_IMPL_INIT(mutex) pthread_mutex_init (&(mutex), NULL)
 180 #endif
 181 # define CAIRO_MUTEX_IMPL_LOCK(mutex) pthread_mutex_lock (&(mutex))
 182 # define CAIRO_MUTEX_IMPL_UNLOCK(mutex) pthread_mutex_unlock (&(mutex))
 183 #if HAVE_LOCKDEP
 184 # define CAIRO_MUTEX_IS_LOCKED(mutex) LOCKDEP_IS_LOCKED (&(mutex))
 185 # define CAIRO_MUTEX_IS_UNLOCKED(mutex) LOCKDEP_IS_UNLOCKED (&(mutex))
 186 #endif
 187 # define CAIRO_MUTEX_IMPL_FINI(mutex) pthread_mutex_destroy (&(mutex))
 188 #if ! HAVE_LOCKDEP
 189 # define CAIRO_MUTEX_IMPL_FINALIZE() CAIRO_MUTEX_IMPL_NOOP
 190 #endif
 191 # define CAIRO_MUTEX_IMPL_NIL_INITIALIZER PTHREAD_MUTEX_INITIALIZER
 192
 193 #elif defined(HAVE_WINDOWS_H) || defined(_MSC_VER) /*************************/
 194
 195 # include <windows.h>
 196
 197   typedef CRITICAL_SECTION cairo_mutex_impl_t;
 198
 199 # define CAIRO_MUTEX_IMPL_WIN32 1
 200 # define CAIRO_MUTEX_IMPL_LOCK(mutex) EnterCriticalSection (&(mutex))
 201 # define CAIRO_MUTEX_IMPL_UNLOCK(mutex) LeaveCriticalSection (&(mutex))
 202 # define CAIRO_MUTEX_IMPL_INIT(mutex) InitializeCriticalSection (&(mutex))
 203 # define CAIRO_MUTEX_IMPL_FINI(mutex) DeleteCriticalSection (&(mutex))
 204 # define CAIRO_MUTEX_IMPL_NIL_INITIALIZER { NULL, 0, 0, NULL, NULL, 0 }
 205
 206 #elif defined __OS2__ /******************************************************/
 207
 208 # define INCL_BASE
 209 # define INCL_PM
 210 # include <os2.h>
 211
 212   typedef HMTX cairo_mutex_impl_t;
 213
 214 # define CAIRO_MUTEX_IMPL_OS2 1
 215 # define CAIRO_MUTEX_IMPL_LOCK(mutex) DosRequestMutexSem(mutex, SEM_INDEFINITE_WAIT)
 216 # define CAIRO_MUTEX_IMPL_UNLOCK(mutex) DosReleaseMutexSem(mutex)
 217 # define CAIRO_MUTEX_IMPL_INIT(mutex) DosCreateMutexSem (NULL, &(mutex), 0L, FALSE)
 218 # define CAIRO_MUTEX_IMPL_FINI(mutex) DosCloseMutexSem (mutex)
 219 # define CAIRO_MUTEX_IMPL_NIL_INITIALIZER 0
 220
 221 #elif CAIRO_HAS_BEOS_SURFACE /***********************************************/
 222
 223   typedef BLocker* cairo_mutex_impl_t;
 224
 225 # define CAIRO_MUTEX_IMPL_BEOS 1
 226 # define CAIRO_MUTEX_IMPL_LOCK(mutex) (mutex)->Lock()
 227 # define CAIRO_MUTEX_IMPL_UNLOCK(mutex) (mutex)->Unlock()
 228 # define CAIRO_MUTEX_IMPL_INIT(mutex) (mutex) = new BLocker()
 229 # define CAIRO_MUTEX_IMPL_FINI(mutex) delete (mutex)
 230 # define CAIRO_MUTEX_IMPL_NIL_INITIALIZER NULL
 231
 232 #else /**********************************************************************/
 233
 234 # error "XXX: No mutex implementation found.  Cairo will not work with multiple threads.  Define CAIRO_NO_MUTEX to 1 to acknowledge and accept this limitation and compile cairo without thread-safety support."
 235
 236
 237 #endif
 238
 239 #endif