1 /** 2 * util/locks.h - unbound locking primitives 3 * 4 * Copyright (c) 2007, NLnet Labs. All rights reserved. 5 * 6 * This software is open source. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 12 * Redistributions of source code must retain the above copyright notice, 13 * this list of conditions and the following disclaimer. 14 * 15 * Redistributions in binary form must reproduce the above copyright notice, 16 * this list of conditions and the following disclaimer in the documentation 17 * and/or other materials provided with the distribution. 18 * 19 * Neither the name of the NLNET LABS nor the names of its contributors may 20 * be used to endorse or promote products derived from this software without 21 * specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 24 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 25 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 26 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 27 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 28 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED 29 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 30 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 31 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 32 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 33 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 34 */ 35 36 #ifndef UTIL_LOCKS_H 37 #define UTIL_LOCKS_H 38 39 /** 40 * \file 41 * Locking primitives. 42 * If pthreads is available, these are used. 43 * If no locking exists, they do nothing. 44 * 45 * The idea is to have different sorts of locks for different tasks. 46 * This allows the locking code to be ported more easily. 47 * 48 * Types of locks that are supported. 49 * o lock_rw: lock that has many readers and one writer (to a data entry). 50 * o lock_basic: simple mutex. Blocking, one person has access only. 51 * This lock is meant for non performance sensitive uses. 52 * o lock_quick: speed lock. For performance sensitive locking of critical 53 * sections. Could be implemented by a mutex or a spinlock. 54 * 55 * Also thread creation and deletion functions are defined here. 56 */ 57 58 /* if you define your own LOCKRET before including locks.h, you can get most 59 * locking functions without the dependency on log_err. */ 60 #ifndef LOCKRET 61 #include "util/log.h" 62 /** 63 * The following macro is used to check the return value of the 64 * pthread calls. They return 0 on success and an errno on error. 65 * The errno is logged to the logfile with a descriptive comment. 66 */ 67 #define LOCKRET(func) do {\ 68 int lockret_err; \ 69 if( (lockret_err=(func)) != 0) \ 70 log_err("%s at %d could not " #func ": %s", \ 71 __FILE__, __LINE__, strerror(lockret_err)); \ 72 } while(0) 73 #endif 74 75 /** DEBUG: use thread debug whenever possible */ 76 #if defined(HAVE_PTHREAD) && defined(HAVE_PTHREAD_SPINLOCK_T) && defined(ENABLE_LOCK_CHECKS) 77 # define USE_THREAD_DEBUG 78 #endif 79 80 #ifdef USE_THREAD_DEBUG 81 /******************* THREAD DEBUG ************************/ 82 /* (some) checking; to detect races and deadlocks. */ 83 #include "testcode/checklocks.h" 84 85 #else /* USE_THREAD_DEBUG */ 86 #define lock_protect(lock, area, size) /* nop */ 87 #define lock_unprotect(lock, area) /* nop */ 88 #define lock_get_mem(lock) (0) /* nothing */ 89 #define checklock_start() /* nop */ 90 #define checklock_stop() /* nop */ 91 92 #ifdef HAVE_PTHREAD 93 #include <pthread.h> 94 95 /******************* PTHREAD ************************/ 96 97 /** use pthread mutex for basic lock */ 98 typedef pthread_mutex_t lock_basic_t; 99 /** small front for pthread init func, NULL is default attrs. */ 100 #define lock_basic_init(lock) LOCKRET(pthread_mutex_init(lock, NULL)) 101 #define lock_basic_destroy(lock) LOCKRET(pthread_mutex_destroy(lock)) 102 #define lock_basic_lock(lock) LOCKRET(pthread_mutex_lock(lock)) 103 #define lock_basic_unlock(lock) LOCKRET(pthread_mutex_unlock(lock)) 104 105 #ifndef HAVE_PTHREAD_RWLOCK_T 106 /** in case rwlocks are not supported, use a mutex. */ 107 typedef pthread_mutex_t lock_rw_t; 108 #define lock_rw_init(lock) LOCKRET(pthread_mutex_init(lock, NULL)) 109 #define lock_rw_destroy(lock) LOCKRET(pthread_mutex_destroy(lock)) 110 #define lock_rw_rdlock(lock) LOCKRET(pthread_mutex_lock(lock)) 111 #define lock_rw_wrlock(lock) LOCKRET(pthread_mutex_lock(lock)) 112 #define lock_rw_unlock(lock) LOCKRET(pthread_mutex_unlock(lock)) 113 #else /* HAVE_PTHREAD_RWLOCK_T */ 114 /** we use the pthread rwlock */ 115 typedef pthread_rwlock_t lock_rw_t; 116 /** small front for pthread init func, NULL is default attrs. */ 117 #define lock_rw_init(lock) LOCKRET(pthread_rwlock_init(lock, NULL)) 118 #define lock_rw_destroy(lock) LOCKRET(pthread_rwlock_destroy(lock)) 119 #define lock_rw_rdlock(lock) LOCKRET(pthread_rwlock_rdlock(lock)) 120 #define lock_rw_wrlock(lock) LOCKRET(pthread_rwlock_wrlock(lock)) 121 #define lock_rw_unlock(lock) LOCKRET(pthread_rwlock_unlock(lock)) 122 #endif /* HAVE_PTHREAD_RWLOCK_T */ 123 124 #ifndef HAVE_PTHREAD_SPINLOCK_T 125 /** in case spinlocks are not supported, use a mutex. */ 126 typedef pthread_mutex_t lock_quick_t; 127 /** small front for pthread init func, NULL is default attrs. */ 128 #define lock_quick_init(lock) LOCKRET(pthread_mutex_init(lock, NULL)) 129 #define lock_quick_destroy(lock) LOCKRET(pthread_mutex_destroy(lock)) 130 #define lock_quick_lock(lock) LOCKRET(pthread_mutex_lock(lock)) 131 #define lock_quick_unlock(lock) LOCKRET(pthread_mutex_unlock(lock)) 132 133 #else /* HAVE_PTHREAD_SPINLOCK_T */ 134 /** use pthread spinlock for the quick lock */ 135 typedef pthread_spinlock_t lock_quick_t; 136 /** 137 * allocate process private since this is available whether 138 * Thread Process-Shared Synchronization is supported or not. 139 * This means only threads inside this process may access the lock. 140 * (not threads from another process that shares memory). 141 * spinlocks are not supported on all pthread platforms. 142 */ 143 #define lock_quick_init(lock) LOCKRET(pthread_spin_init(lock, PTHREAD_PROCESS_PRIVATE)) 144 #define lock_quick_destroy(lock) LOCKRET(pthread_spin_destroy(lock)) 145 #define lock_quick_lock(lock) LOCKRET(pthread_spin_lock(lock)) 146 #define lock_quick_unlock(lock) LOCKRET(pthread_spin_unlock(lock)) 147 148 #endif /* HAVE SPINLOCK */ 149 150 /** Thread creation */ 151 typedef pthread_t ub_thread_t; 152 /** Pass where to store tread_t in thr. Use default NULL attributes. */ 153 #define ub_thread_create(thr, func, arg) LOCKRET(pthread_create(thr, NULL, func, arg)) 154 /** get self id. */ 155 #define ub_thread_self() pthread_self() 156 /** wait for another thread to terminate */ 157 #define ub_thread_join(thread) LOCKRET(pthread_join(thread, NULL)) 158 typedef pthread_key_t ub_thread_key_t; 159 #define ub_thread_key_create(key, f) LOCKRET(pthread_key_create(key, f)) 160 #define ub_thread_key_set(key, v) LOCKRET(pthread_setspecific(key, v)) 161 #define ub_thread_key_get(key) pthread_getspecific(key) 162 163 #else /* we do not HAVE_PTHREAD */ 164 #ifdef HAVE_SOLARIS_THREADS 165 166 /******************* SOLARIS THREADS ************************/ 167 #include <synch.h> 168 #include <thread.h> 169 170 typedef rwlock_t lock_rw_t; 171 #define lock_rw_init(lock) LOCKRET(rwlock_init(lock, USYNC_THREAD, NULL)) 172 #define lock_rw_destroy(lock) LOCKRET(rwlock_destroy(lock)) 173 #define lock_rw_rdlock(lock) LOCKRET(rw_rdlock(lock)) 174 #define lock_rw_wrlock(lock) LOCKRET(rw_wrlock(lock)) 175 #define lock_rw_unlock(lock) LOCKRET(rw_unlock(lock)) 176 177 /** use basic mutex */ 178 typedef mutex_t lock_basic_t; 179 #define lock_basic_init(lock) LOCKRET(mutex_init(lock, USYNC_THREAD, NULL)) 180 #define lock_basic_destroy(lock) LOCKRET(mutex_destroy(lock)) 181 #define lock_basic_lock(lock) LOCKRET(mutex_lock(lock)) 182 #define lock_basic_unlock(lock) LOCKRET(mutex_unlock(lock)) 183 184 /** No spinlocks in solaris threads API. Use a mutex. */ 185 typedef mutex_t lock_quick_t; 186 #define lock_quick_init(lock) LOCKRET(mutex_init(lock, USYNC_THREAD, NULL)) 187 #define lock_quick_destroy(lock) LOCKRET(mutex_destroy(lock)) 188 #define lock_quick_lock(lock) LOCKRET(mutex_lock(lock)) 189 #define lock_quick_unlock(lock) LOCKRET(mutex_unlock(lock)) 190 191 /** Thread creation, create a default thread. */ 192 typedef thread_t ub_thread_t; 193 #define ub_thread_create(thr, func, arg) LOCKRET(thr_create(NULL, NULL, func, arg, NULL, thr)) 194 #define ub_thread_self() thr_self() 195 #define ub_thread_join(thread) LOCKRET(thr_join(thread, NULL, NULL)) 196 typedef thread_key_t ub_thread_key_t; 197 #define ub_thread_key_create(key, f) LOCKRET(thr_keycreate(key, f)) 198 #define ub_thread_key_set(key, v) LOCKRET(thr_setspecific(key, v)) 199 void* ub_thread_key_get(ub_thread_key_t key); 200 201 202 #else /* we do not HAVE_SOLARIS_THREADS and no PTHREADS */ 203 /******************* WINDOWS THREADS ************************/ 204 #ifdef HAVE_WINDOWS_THREADS 205 #include <windows.h> 206 207 /* Use a mutex */ 208 typedef LONG lock_rw_t; 209 #define lock_rw_init(lock) lock_basic_init(lock) 210 #define lock_rw_destroy(lock) lock_basic_destroy(lock) 211 #define lock_rw_rdlock(lock) lock_basic_lock(lock) 212 #define lock_rw_wrlock(lock) lock_basic_lock(lock) 213 #define lock_rw_unlock(lock) lock_basic_unlock(lock) 214 215 /** the basic lock is a mutex, implemented opaquely, for error handling. */ 216 typedef LONG lock_basic_t; 217 void lock_basic_init(lock_basic_t* lock); 218 void lock_basic_destroy(lock_basic_t* lock); 219 void lock_basic_lock(lock_basic_t* lock); 220 void lock_basic_unlock(lock_basic_t* lock); 221 222 /** on windows no spinlock, use mutex too. */ 223 typedef LONG lock_quick_t; 224 #define lock_quick_init(lock) lock_basic_init(lock) 225 #define lock_quick_destroy(lock) lock_basic_destroy(lock) 226 #define lock_quick_lock(lock) lock_basic_lock(lock) 227 #define lock_quick_unlock(lock) lock_basic_unlock(lock) 228 229 /** Thread creation, create a default thread. */ 230 typedef HANDLE ub_thread_t; 231 void ub_thread_create(ub_thread_t* thr, void* (*func)(void*), void* arg); 232 ub_thread_t ub_thread_self(void); 233 void ub_thread_join(ub_thread_t thr); 234 typedef DWORD ub_thread_key_t; 235 void ub_thread_key_create(ub_thread_key_t* key, void* f); 236 void ub_thread_key_set(ub_thread_key_t key, void* v); 237 void* ub_thread_key_get(ub_thread_key_t key); 238 239 #else /* we do not HAVE_SOLARIS_THREADS, PTHREADS or WINDOWS_THREADS */ 240 241 /******************* NO THREADS ************************/ 242 #define THREADS_DISABLED 1 243 /** In case there is no thread support, define locks to do nothing */ 244 typedef int lock_rw_t; 245 #define lock_rw_init(lock) /* nop */ 246 #define lock_rw_destroy(lock) /* nop */ 247 #define lock_rw_rdlock(lock) /* nop */ 248 #define lock_rw_wrlock(lock) /* nop */ 249 #define lock_rw_unlock(lock) /* nop */ 250 251 /** define locks to do nothing */ 252 typedef int lock_basic_t; 253 #define lock_basic_init(lock) /* nop */ 254 #define lock_basic_destroy(lock) /* nop */ 255 #define lock_basic_lock(lock) /* nop */ 256 #define lock_basic_unlock(lock) /* nop */ 257 258 /** define locks to do nothing */ 259 typedef int lock_quick_t; 260 #define lock_quick_init(lock) /* nop */ 261 #define lock_quick_destroy(lock) /* nop */ 262 #define lock_quick_lock(lock) /* nop */ 263 #define lock_quick_unlock(lock) /* nop */ 264 265 /** Thread creation, threads do not exist */ 266 typedef pid_t ub_thread_t; 267 /** ub_thread_create is simulated with fork (extremely heavy threads, 268 * with no shared memory). */ 269 #define ub_thread_create(thr, func, arg) \ 270 ub_thr_fork_create(thr, func, arg) 271 #define ub_thread_self() getpid() 272 #define ub_thread_join(thread) ub_thr_fork_wait(thread) 273 void ub_thr_fork_wait(ub_thread_t thread); 274 void ub_thr_fork_create(ub_thread_t* thr, void* (*func)(void*), void* arg); 275 typedef void* ub_thread_key_t; 276 #define ub_thread_key_create(key, f) (*(key)) = NULL 277 #define ub_thread_key_set(key, v) (key) = (v) 278 #define ub_thread_key_get(key) (key) 279 280 #endif /* HAVE_WINDOWS_THREADS */ 281 #endif /* HAVE_SOLARIS_THREADS */ 282 #endif /* HAVE_PTHREAD */ 283 #endif /* USE_THREAD_DEBUG */ 284 285 /** 286 * Block all signals for this thread. 287 * fatal exit on error. 288 */ 289 void ub_thread_blocksigs(void); 290 291 /** 292 * unblock one signal for this thread. 293 */ 294 void ub_thread_sig_unblock(int sig); 295 296 #endif /* UTIL_LOCKS_H */ 297