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         }
 140
 141         pthread_mutex_unlock(&mutex->lock);
 142         return ret;
 143 }
 144
 145 bool fio_mutex_down_trylock(struct fio_mutex *mutex)
 146 {
 147         bool ret = true;
 148
 149         assert(mutex->magic == FIO_MUTEX_MAGIC);
 150
 151         pthread_mutex_lock(&mutex->lock);
 152         if (mutex->value) {
 153                 mutex->value--;
 154                 ret = false;
 155         }
 156         pthread_mutex_unlock(&mutex->lock);
 157
 158         return ret;
 159 }
 160
 161 void fio_mutex_down(struct fio_mutex *mutex)
 162 {
 163         assert(mutex->magic == FIO_MUTEX_MAGIC);
 164
 165         pthread_mutex_lock(&mutex->lock);
 166
 167         while (!mutex->value) {
 168                 mutex->waiters++;
 169                 pthread_cond_wait(&mutex->cond, &mutex->lock);
 170                 mutex->waiters--;
 171         }
 172
 173         mutex->value--;
 174         pthread_mutex_unlock(&mutex->lock);
 175 }
 176
 177 void fio_mutex_up(struct fio_mutex *mutex)
 178 {
 179         int do_wake = 0;
 180
 181         assert(mutex->magic == FIO_MUTEX_MAGIC);
 182
 183         pthread_mutex_lock(&mutex->lock);
 184         read_barrier();
 185         if (!mutex->value && mutex->waiters)
 186                 do_wake = 1;
 187         mutex->value++;
 188         pthread_mutex_unlock(&mutex->lock);
 189
 190         if (do_wake)
 191                 pthread_cond_signal(&mutex->cond);
 192 }
 193
 194 void fio_rwlock_write(struct fio_rwlock *lock)
 195 {
 196         assert(lock->magic == FIO_RWLOCK_MAGIC);
 197         pthread_rwlock_wrlock(&lock->lock);
 198 }
 199
 200 void fio_rwlock_read(struct fio_rwlock *lock)
 201 {
 202         assert(lock->magic == FIO_RWLOCK_MAGIC);
 203         pthread_rwlock_rdlock(&lock->lock);
 204 }
 205
 206 void fio_rwlock_unlock(struct fio_rwlock *lock)
 207 {
 208         assert(lock->magic == FIO_RWLOCK_MAGIC);
 209         pthread_rwlock_unlock(&lock->lock);
 210 }
 211
 212 void fio_rwlock_remove(struct fio_rwlock *lock)
 213 {
 214         assert(lock->magic == FIO_RWLOCK_MAGIC);
 215         munmap((void *) lock, sizeof(*lock));
 216 }
 217
 218 struct fio_rwlock *fio_rwlock_init(void)
 219 {
 220         struct fio_rwlock *lock;
 221         pthread_rwlockattr_t attr;
 222         int ret;
 223
 224         lock = (void *) mmap(NULL, sizeof(struct fio_rwlock),
 225                                 PROT_READ | PROT_WRITE,
 226                                 OS_MAP_ANON | MAP_SHARED, -1, 0);
 227         if (lock == MAP_FAILED) {
 228                 perror("mmap rwlock");
 229                 lock = NULL;
 230                 goto err;
 231         }
 232
 233         lock->magic = FIO_RWLOCK_MAGIC;
 234
 235         ret = pthread_rwlockattr_init(&attr);
 236         if (ret) {
 237                 log_err("pthread_rwlockattr_init: %s\n", strerror(ret));
 238                 goto err;
 239         }
 240 #ifdef FIO_HAVE_PSHARED_MUTEX
 241         ret = pthread_rwlockattr_setpshared(&attr, PTHREAD_PROCESS_SHARED);
 242         if (ret) {
 243                 log_err("pthread_rwlockattr_setpshared: %s\n", strerror(ret));
 244                 goto destroy_attr;
 245         }
 246
 247         ret = pthread_rwlock_init(&lock->lock, &attr);
 248 #else
 249         ret = pthread_rwlock_init(&lock->lock, NULL);
 250 #endif
 251
 252         if (ret) {
 253                 log_err("pthread_rwlock_init: %s\n", strerror(ret));
 254                 goto destroy_attr;
 255         }
 256
 257         pthread_rwlockattr_destroy(&attr);
 258
 259         return lock;
 260 destroy_attr:
 261         pthread_rwlockattr_destroy(&attr);
 262 err:
 263         if (lock)
 264                 fio_rwlock_remove(lock);
 265         return NULL;
 266 }