mutex.c

   1 #include <stdio.h>
   2 #include <string.h>
   3 #include <unistd.h>
   4 #include <stdlib.h>
   5 #include <fcntl.h>
   6 #include <time.h>
   7 #include <errno.h>
   8 #include <pthread.h>
   9 #include <sys/mman.h>
  10 #include <assert.h>
  11
  12 #include "fio.h"
  13 #include "log.h"
  14 #include "mutex.h"
  15 #include "arch/arch.h"
  16 #include "os/os.h"
  17 #include "helpers.h"
  18 #include "fio_time.h"
  19 #include "gettime.h"
  20
  21 void __fio_mutex_remove(struct fio_mutex *mutex)
  22 {
  23         assert(mutex->magic == FIO_MUTEX_MAGIC);
  24         pthread_cond_destroy(&mutex->cond);
  25 }
  26
  27 void fio_mutex_remove(struct fio_mutex *mutex)
  28 {
  29         __fio_mutex_remove(mutex);
  30         munmap((void *) mutex, sizeof(*mutex));
  31 }
  32
  33 int __fio_mutex_init(struct fio_mutex *mutex, int value)
  34 {
  35         pthread_mutexattr_t attr;
  36         pthread_condattr_t cond;
  37         int ret;
  38
  39         mutex->value = value;
  40         mutex->magic = FIO_MUTEX_MAGIC;
  41
  42         ret = pthread_mutexattr_init(&attr);
  43         if (ret) {
  44                 log_err("pthread_mutexattr_init: %s\n", strerror(ret));
  45                 return ret;
  46         }
  47
  48         /*
  49          * Not all platforms support process shared mutexes (FreeBSD)
  50          */
  51 #ifdef FIO_HAVE_PSHARED_MUTEX
  52         ret = pthread_mutexattr_setpshared(&attr, PTHREAD_PROCESS_SHARED);
  53         if (ret) {
  54                 log_err("pthread_mutexattr_setpshared: %s\n", strerror(ret));
  55                 return ret;
  56         }
  57 #endif
  58
  59         pthread_condattr_init(&cond);
  60 #ifdef FIO_HAVE_PSHARED_MUTEX
  61         pthread_condattr_setpshared(&cond, PTHREAD_PROCESS_SHARED);
  62 #endif
  63         pthread_cond_init(&mutex->cond, &cond);
  64
  65         ret = pthread_mutex_init(&mutex->lock, &attr);
  66         if (ret) {
  67                 log_err("pthread_mutex_init: %s\n", strerror(ret));
  68                 return ret;
  69         }
  70
  71         pthread_condattr_destroy(&cond);
  72         pthread_mutexattr_destroy(&attr);
  73         return 0;
  74 }
  75
  76 struct fio_mutex *fio_mutex_init(int value)
  77 {
  78         struct fio_mutex *mutex = NULL;
  79
  80         mutex = (void *) mmap(NULL, sizeof(struct fio_mutex),
  81                                 PROT_READ | PROT_WRITE,
  82                                 OS_MAP_ANON | MAP_SHARED, -1, 0);
  83         if (mutex == MAP_FAILED) {
  84                 perror("mmap mutex");
  85                 return NULL;
  86         }
  87
  88         if (!__fio_mutex_init(mutex, value))
  89                 return mutex;
  90
  91         fio_mutex_remove(mutex);
  92         return NULL;
  93 }
  94
  95 static bool mutex_timed_out(struct timeval *t, unsigned int msecs)
  96 {
  97         struct timeval now;
  98
  99         gettimeofday(&now, NULL);
 100         return mtime_since(t, &now) >= msecs;
 101 }
 102
 103 int fio_mutex_down_timeout(struct fio_mutex *mutex, unsigned int msecs)
 104 {
 105         struct timeval tv_s;
 106         struct timespec t;
 107         int ret = 0;
 108
 109         assert(mutex->magic == FIO_MUTEX_MAGIC);
 110
 111         gettimeofday(&tv_s, NULL);
 112         t.tv_sec = tv_s.tv_sec;
 113         t.tv_nsec = tv_s.tv_usec * 1000;
 114
 115         t.tv_sec += msecs / 1000;
 116         t.tv_nsec += ((msecs * 1000000) % 1000000000);
 117         if (t.tv_nsec >= 1000000000) {
 118                 t.tv_nsec -= 1000000000;
 119                 t.tv_sec++;
 120         }
 121
 122         pthread_mutex_lock(&mutex->lock);
 123
 124         mutex->waiters++;
 125         while (!mutex->value && !ret) {
 126                 /*
 127                  * Some platforms (FreeBSD 9?) seems to return timed out
 128                  * way too early, double check.
 129                  */
 130                 ret = pthread_cond_timedwait(&mutex->cond, &mutex->lock, &t);
 131                 if (ret == ETIMEDOUT && !mutex_timed_out(&tv_s, msecs))
 132                         ret = 0;
 133         }
 134         mutex->waiters--;
 135
 136         if (!ret) {
 137                 mutex->value--;
 138                 pthread_mutex_unlock(&mutex->lock);
 139                 return 0;
 140         }
 141
 142         pthread_mutex_unlock(&mutex->lock);
 143         return ret;
 144 }
 145
 146 bool fio_mutex_down_trylock(struct fio_mutex *mutex)
 147 {
 148         bool ret = true;
 149
 150         assert(mutex->magic == FIO_MUTEX_MAGIC);
 151
 152         pthread_mutex_lock(&mutex->lock);
 153         if (mutex->value) {
 154                 mutex->value--;
 155                 ret = false;
 156         }
 157         pthread_mutex_unlock(&mutex->lock);
 158
 159         return ret;
 160 }
 161
 162 void fio_mutex_down(struct fio_mutex *mutex)
 163 {
 164         assert(mutex->magic == FIO_MUTEX_MAGIC);
 165
 166         pthread_mutex_lock(&mutex->lock);
 167
 168         while (!mutex->value) {
 169                 mutex->waiters++;
 170                 pthread_cond_wait(&mutex->cond, &mutex->lock);
 171                 mutex->waiters--;
 172         }
 173
 174         mutex->value--;
 175         pthread_mutex_unlock(&mutex->lock);
 176 }
 177
 178 void fio_mutex_up(struct fio_mutex *mutex)
 179 {
 180         int do_wake = 0;
 181
 182         assert(mutex->magic == FIO_MUTEX_MAGIC);
 183
 184         pthread_mutex_lock(&mutex->lock);
 185         read_barrier();
 186         if (!mutex->value && mutex->waiters)
 187                 do_wake = 1;
 188         mutex->value++;
 189         pthread_mutex_unlock(&mutex->lock);
 190
 191         if (do_wake)
 192                 pthread_cond_signal(&mutex->cond);
 193 }
 194
 195 void fio_rwlock_write(struct fio_rwlock *lock)
 196 {
 197         assert(lock->magic == FIO_RWLOCK_MAGIC);
 198         pthread_rwlock_wrlock(&lock->lock);
 199 }
 200
 201 void fio_rwlock_read(struct fio_rwlock *lock)
 202 {
 203         assert(lock->magic == FIO_RWLOCK_MAGIC);
 204         pthread_rwlock_rdlock(&lock->lock);
 205 }
 206
 207 void fio_rwlock_unlock(struct fio_rwlock *lock)
 208 {
 209         assert(lock->magic == FIO_RWLOCK_MAGIC);
 210         pthread_rwlock_unlock(&lock->lock);
 211 }
 212
 213 void fio_rwlock_remove(struct fio_rwlock *lock)
 214 {
 215         assert(lock->magic == FIO_RWLOCK_MAGIC);
 216         munmap((void *) lock, sizeof(*lock));
 217 }
 218
 219 struct fio_rwlock *fio_rwlock_init(void)
 220 {
 221         struct fio_rwlock *lock;
 222         pthread_rwlockattr_t attr;
 223         int ret;
 224
 225         lock = (void *) mmap(NULL, sizeof(struct fio_rwlock),
 226                                 PROT_READ | PROT_WRITE,
 227                                 OS_MAP_ANON | MAP_SHARED, -1, 0);
 228         if (lock == MAP_FAILED) {
 229                 perror("mmap rwlock");
 230                 lock = NULL;
 231                 goto err;
 232         }
 233
 234         lock->magic = FIO_RWLOCK_MAGIC;
 235
 236         ret = pthread_rwlockattr_init(&attr);
 237         if (ret) {
 238                 log_err("pthread_rwlockattr_init: %s\n", strerror(ret));
 239                 goto err;
 240         }
 241 #ifdef FIO_HAVE_PSHARED_MUTEX
 242         ret = pthread_rwlockattr_setpshared(&attr, PTHREAD_PROCESS_SHARED);
 243         if (ret) {
 244                 log_err("pthread_rwlockattr_setpshared: %s\n", strerror(ret));
 245                 goto destroy_attr;
 246         }
 247
 248         ret = pthread_rwlock_init(&lock->lock, &attr);
 249 #else
 250         ret = pthread_rwlock_init(&lock->lock, NULL);
 251 #endif
 252
 253         if (ret) {
 254                 log_err("pthread_rwlock_init: %s\n", strerror(ret));
 255                 goto destroy_attr;
 256         }
 257
 258         pthread_rwlockattr_destroy(&attr);
 259
 260         return lock;
 261 destroy_attr:
 262         pthread_rwlockattr_destroy(&attr);
 263 err:
 264         if (lock)
 265                 fio_rwlock_remove(lock);
 266         return NULL;
 267 }