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_type; 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_type; 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_type; 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_type; 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_type; 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_type; 152 /** On alpine linux default thread stack size is 80 Kb. See 153 http://wiki.musl-libc.org/wiki/Functional_differences_from_glibc#Thread_stack_size 154 This is not enough and cause segfault. Other linux distros have 2 Mb at least. 155 Wrapper for set up thread stack size */ 156 #define PTHREADSTACKSIZE 2*1024*1024 157 #define PTHREADCREATE(thr, stackrequired, func, arg) do {\ 158 pthread_attr_t attr; \ 159 size_t stacksize; \ 160 LOCKRET(pthread_attr_init(&attr)); \ 161 LOCKRET(pthread_attr_getstacksize(&attr, &stacksize)); \ 162 if (stacksize < stackrequired) { \ 163 LOCKRET(pthread_attr_setstacksize(&attr, stackrequired)); \ 164 LOCKRET(pthread_create(thr, &attr, func, arg)); \ 165 LOCKRET(pthread_attr_getstacksize(&attr, &stacksize)); \ 166 verbose(VERB_ALGO, "Thread stack size set to %u", (unsigned)stacksize); \ 167 } else {LOCKRET(pthread_create(thr, NULL, func, arg));} \ 168 } while(0) 169 /** Use wrapper for set thread stack size on attributes. */ 170 #define ub_thread_create(thr, func, arg) PTHREADCREATE(thr, PTHREADSTACKSIZE, func, arg) 171 /** get self id. */ 172 #define ub_thread_self() pthread_self() 173 /** wait for another thread to terminate */ 174 #define ub_thread_join(thread) LOCKRET(pthread_join(thread, NULL)) 175 typedef pthread_key_t ub_thread_key_type; 176 #define ub_thread_key_create(key, f) LOCKRET(pthread_key_create(key, f)) 177 #define ub_thread_key_set(key, v) LOCKRET(pthread_setspecific(key, v)) 178 #define ub_thread_key_get(key) pthread_getspecific(key) 179 180 #else /* we do not HAVE_PTHREAD */ 181 #ifdef HAVE_SOLARIS_THREADS 182 183 /******************* SOLARIS THREADS ************************/ 184 #include <synch.h> 185 #include <thread.h> 186 187 typedef rwlock_t lock_rw_type; 188 #define lock_rw_init(lock) LOCKRET(rwlock_init(lock, USYNC_THREAD, NULL)) 189 #define lock_rw_destroy(lock) LOCKRET(rwlock_destroy(lock)) 190 #define lock_rw_rdlock(lock) LOCKRET(rw_rdlock(lock)) 191 #define lock_rw_wrlock(lock) LOCKRET(rw_wrlock(lock)) 192 #define lock_rw_unlock(lock) LOCKRET(rw_unlock(lock)) 193 194 /** use basic mutex */ 195 typedef mutex_t lock_basic_type; 196 #define lock_basic_init(lock) LOCKRET(mutex_init(lock, USYNC_THREAD, NULL)) 197 #define lock_basic_destroy(lock) LOCKRET(mutex_destroy(lock)) 198 #define lock_basic_lock(lock) LOCKRET(mutex_lock(lock)) 199 #define lock_basic_unlock(lock) LOCKRET(mutex_unlock(lock)) 200 201 /** No spinlocks in solaris threads API. Use a mutex. */ 202 typedef mutex_t lock_quick_type; 203 #define lock_quick_init(lock) LOCKRET(mutex_init(lock, USYNC_THREAD, NULL)) 204 #define lock_quick_destroy(lock) LOCKRET(mutex_destroy(lock)) 205 #define lock_quick_lock(lock) LOCKRET(mutex_lock(lock)) 206 #define lock_quick_unlock(lock) LOCKRET(mutex_unlock(lock)) 207 208 /** Thread creation, create a default thread. */ 209 typedef thread_t ub_thread_type; 210 #define ub_thread_create(thr, func, arg) LOCKRET(thr_create(NULL, NULL, func, arg, NULL, thr)) 211 #define ub_thread_self() thr_self() 212 #define ub_thread_join(thread) LOCKRET(thr_join(thread, NULL, NULL)) 213 typedef thread_key_t ub_thread_key_type; 214 #define ub_thread_key_create(key, f) LOCKRET(thr_keycreate(key, f)) 215 #define ub_thread_key_set(key, v) LOCKRET(thr_setspecific(key, v)) 216 void* ub_thread_key_get(ub_thread_key_type key); 217 218 219 #else /* we do not HAVE_SOLARIS_THREADS and no PTHREADS */ 220 /******************* WINDOWS THREADS ************************/ 221 #ifdef HAVE_WINDOWS_THREADS 222 #include <windows.h> 223 224 /* Use a mutex */ 225 typedef LONG lock_rw_type; 226 #define lock_rw_init(lock) lock_basic_init(lock) 227 #define lock_rw_destroy(lock) lock_basic_destroy(lock) 228 #define lock_rw_rdlock(lock) lock_basic_lock(lock) 229 #define lock_rw_wrlock(lock) lock_basic_lock(lock) 230 #define lock_rw_unlock(lock) lock_basic_unlock(lock) 231 232 /** the basic lock is a mutex, implemented opaquely, for error handling. */ 233 typedef LONG lock_basic_type; 234 void lock_basic_init(lock_basic_type* lock); 235 void lock_basic_destroy(lock_basic_type* lock); 236 void lock_basic_lock(lock_basic_type* lock); 237 void lock_basic_unlock(lock_basic_type* lock); 238 239 /** on windows no spinlock, use mutex too. */ 240 typedef LONG lock_quick_type; 241 #define lock_quick_init(lock) lock_basic_init(lock) 242 #define lock_quick_destroy(lock) lock_basic_destroy(lock) 243 #define lock_quick_lock(lock) lock_basic_lock(lock) 244 #define lock_quick_unlock(lock) lock_basic_unlock(lock) 245 246 /** Thread creation, create a default thread. */ 247 typedef HANDLE ub_thread_type; 248 void ub_thread_create(ub_thread_type* thr, void* (*func)(void*), void* arg); 249 ub_thread_type ub_thread_self(void); 250 void ub_thread_join(ub_thread_type thr); 251 typedef DWORD ub_thread_key_type; 252 void ub_thread_key_create(ub_thread_key_type* key, void* f); 253 void ub_thread_key_set(ub_thread_key_type key, void* v); 254 void* ub_thread_key_get(ub_thread_key_type key); 255 256 #else /* we do not HAVE_SOLARIS_THREADS, PTHREADS or WINDOWS_THREADS */ 257 258 /******************* NO THREADS ************************/ 259 #define THREADS_DISABLED 1 260 /** In case there is no thread support, define locks to do nothing */ 261 typedef int lock_rw_type; 262 #define lock_rw_init(lock) /* nop */ 263 #define lock_rw_destroy(lock) /* nop */ 264 #define lock_rw_rdlock(lock) /* nop */ 265 #define lock_rw_wrlock(lock) /* nop */ 266 #define lock_rw_unlock(lock) /* nop */ 267 268 /** define locks to do nothing */ 269 typedef int lock_basic_type; 270 #define lock_basic_init(lock) /* nop */ 271 #define lock_basic_destroy(lock) /* nop */ 272 #define lock_basic_lock(lock) /* nop */ 273 #define lock_basic_unlock(lock) /* nop */ 274 275 /** define locks to do nothing */ 276 typedef int lock_quick_type; 277 #define lock_quick_init(lock) /* nop */ 278 #define lock_quick_destroy(lock) /* nop */ 279 #define lock_quick_lock(lock) /* nop */ 280 #define lock_quick_unlock(lock) /* nop */ 281 282 /** Thread creation, threads do not exist */ 283 typedef pid_t ub_thread_type; 284 /** ub_thread_create is simulated with fork (extremely heavy threads, 285 * with no shared memory). */ 286 #define ub_thread_create(thr, func, arg) \ 287 ub_thr_fork_create(thr, func, arg) 288 #define ub_thread_self() getpid() 289 #define ub_thread_join(thread) ub_thr_fork_wait(thread) 290 void ub_thr_fork_wait(ub_thread_type thread); 291 void ub_thr_fork_create(ub_thread_type* thr, void* (*func)(void*), void* arg); 292 typedef void* ub_thread_key_type; 293 #define ub_thread_key_create(key, f) (*(key)) = NULL 294 #define ub_thread_key_set(key, v) (key) = (v) 295 #define ub_thread_key_get(key) (key) 296 297 #endif /* HAVE_WINDOWS_THREADS */ 298 #endif /* HAVE_SOLARIS_THREADS */ 299 #endif /* HAVE_PTHREAD */ 300 #endif /* USE_THREAD_DEBUG */ 301 302 /** 303 * Block all signals for this thread. 304 * fatal exit on error. 305 */ 306 void ub_thread_blocksigs(void); 307 308 /** 309 * unblock one signal for this thread. 310 */ 311 void ub_thread_sig_unblock(int sig); 312 313 #endif /* UTIL_LOCKS_H */ 314