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 seconds)
  96 {
  97         return mtime_since_now(t) >= seconds * 1000;
  98 }
  99
 100 int fio_mutex_down_timeout(struct fio_mutex *mutex, unsigned int seconds)
 101 {
 102         struct timeval tv_s;
 103         struct timespec t;
 104         int ret = 0;
 105
 106         assert(mutex->magic == FIO_MUTEX_MAGIC);
 107
 108         gettimeofday(&tv_s, NULL);
 109         t.tv_sec = tv_s.tv_sec + seconds;
 110         t.tv_nsec = tv_s.tv_usec * 1000;
 111
 112         pthread_mutex_lock(&mutex->lock);
 113
 114         while (!mutex->value && !ret) {
 115                 mutex->waiters++;
 116
 117                 /*
 118                  * Some platforms (FreeBSD 9?) seems to return timed out
 119                  * way too early, double check.
 120                  */
 121                 ret = pthread_cond_timedwait(&mutex->cond, &mutex->lock, &t);
 122                 if (ret == ETIMEDOUT && !mutex_timed_out(&tv_s, seconds))
 123                         ret = 0;
 124
 125                 mutex->waiters--;
 126         }
 127
 128         if (!ret) {
 129                 mutex->value--;
 130                 pthread_mutex_unlock(&mutex->lock);
 131         }
 132
 133         return ret;
 134 }
 135
 136 bool fio_mutex_down_trylock(struct fio_mutex *mutex)
 137 {
 138         bool ret = true;
 139
 140         assert(mutex->magic == FIO_MUTEX_MAGIC);
 141
 142         pthread_mutex_lock(&mutex->lock);
 143         if (mutex->value) {
 144                 mutex->value--;
 145                 ret = false;
 146         }
 147         pthread_mutex_unlock(&mutex->lock);
 148
 149         return ret;
 150 }
 151
 152 void fio_mutex_down(struct fio_mutex *mutex)
 153 {
 154         assert(mutex->magic == FIO_MUTEX_MAGIC);
 155
 156         pthread_mutex_lock(&mutex->lock);
 157
 158         while (!mutex->value) {
 159                 mutex->waiters++;
 160                 pthread_cond_wait(&mutex->cond, &mutex->lock);
 161                 mutex->waiters--;
 162         }
 163
 164         mutex->value--;
 165         pthread_mutex_unlock(&mutex->lock);
 166 }
 167
 168 void fio_mutex_up(struct fio_mutex *mutex)
 169 {
 170         int do_wake = 0;
 171
 172         assert(mutex->magic == FIO_MUTEX_MAGIC);
 173
 174         pthread_mutex_lock(&mutex->lock);
 175         read_barrier();
 176         if (!mutex->value && mutex->waiters)
 177                 do_wake = 1;
 178         mutex->value++;
 179         pthread_mutex_unlock(&mutex->lock);
 180
 181         if (do_wake)
 182                 pthread_cond_signal(&mutex->cond);
 183 }
 184
 185 void fio_rwlock_write(struct fio_rwlock *lock)
 186 {
 187         assert(lock->magic == FIO_RWLOCK_MAGIC);
 188         pthread_rwlock_wrlock(&lock->lock);
 189 }
 190
 191 void fio_rwlock_read(struct fio_rwlock *lock)
 192 {
 193         assert(lock->magic == FIO_RWLOCK_MAGIC);
 194         pthread_rwlock_rdlock(&lock->lock);
 195 }
 196
 197 void fio_rwlock_unlock(struct fio_rwlock *lock)
 198 {
 199         assert(lock->magic == FIO_RWLOCK_MAGIC);
 200         pthread_rwlock_unlock(&lock->lock);
 201 }
 202
 203 void fio_rwlock_remove(struct fio_rwlock *lock)
 204 {
 205         assert(lock->magic == FIO_RWLOCK_MAGIC);
 206         munmap((void *) lock, sizeof(*lock));
 207 }
 208
 209 struct fio_rwlock *fio_rwlock_init(void)
 210 {
 211         struct fio_rwlock *lock;
 212         pthread_rwlockattr_t attr;
 213         int ret;
 214
 215         lock = (void *) mmap(NULL, sizeof(struct fio_rwlock),
 216                                 PROT_READ | PROT_WRITE,
 217                                 OS_MAP_ANON | MAP_SHARED, -1, 0);
 218         if (lock == MAP_FAILED) {
 219                 perror("mmap rwlock");
 220                 lock = NULL;
 221                 goto err;
 222         }
 223
 224         lock->magic = FIO_RWLOCK_MAGIC;
 225
 226         ret = pthread_rwlockattr_init(&attr);
 227         if (ret) {
 228                 log_err("pthread_rwlockattr_init: %s\n", strerror(ret));
 229                 goto err;
 230         }
 231 #ifdef FIO_HAVE_PSHARED_MUTEX
 232         ret = pthread_rwlockattr_setpshared(&attr, PTHREAD_PROCESS_SHARED);
 233         if (ret) {
 234                 log_err("pthread_rwlockattr_setpshared: %s\n", strerror(ret));
 235                 goto destroy_attr;
 236         }
 237
 238         ret = pthread_rwlock_init(&lock->lock, &attr);
 239 #else
 240         ret = pthread_rwlock_init(&lock->lock, NULL);
 241 #endif
 242
 243         if (ret) {
 244                 log_err("pthread_rwlock_init: %s\n", strerror(ret));
 245                 goto destroy_attr;
 246         }
 247
 248         pthread_rwlockattr_destroy(&attr);
 249
 250         return lock;
 251 destroy_attr:
 252         pthread_rwlockattr_destroy(&attr);
 253 err:
 254         if (lock)
 255                 fio_rwlock_remove(lock);
 256         return NULL;
 257 }