rwlock.c

   1 #include <stdio.h>
   2 #include <string.h>
   3 #include <sys/mman.h>
   4 #include <assert.h>
   5
   6 #include "log.h"
   7 #include "rwlock.h"
   8 #include "os/os.h"
   9
  10 void fio_rwlock_write(struct fio_rwlock *lock)
  11 {
  12         assert(lock->magic == FIO_RWLOCK_MAGIC);
  13         pthread_rwlock_wrlock(&lock->lock);
  14 }
  15
  16 void fio_rwlock_read(struct fio_rwlock *lock)
  17 {
  18         assert(lock->magic == FIO_RWLOCK_MAGIC);
  19         pthread_rwlock_rdlock(&lock->lock);
  20 }
  21
  22 void fio_rwlock_unlock(struct fio_rwlock *lock)
  23 {
  24         assert(lock->magic == FIO_RWLOCK_MAGIC);
  25         pthread_rwlock_unlock(&lock->lock);
  26 }
  27
  28 void fio_rwlock_remove(struct fio_rwlock *lock)
  29 {
  30         assert(lock->magic == FIO_RWLOCK_MAGIC);
  31         munmap((void *) lock, sizeof(*lock));
  32 }
  33
  34 struct fio_rwlock *fio_rwlock_init(void)
  35 {
  36         struct fio_rwlock *lock;
  37         pthread_rwlockattr_t attr;
  38         int ret;
  39
  40         lock = (void *) mmap(NULL, sizeof(struct fio_rwlock),
  41                                 PROT_READ | PROT_WRITE,
  42                                 OS_MAP_ANON | MAP_SHARED, -1, 0);
  43         if (lock == MAP_FAILED) {
  44                 perror("mmap rwlock");
  45                 lock = NULL;
  46                 goto err;
  47         }
  48
  49         lock->magic = FIO_RWLOCK_MAGIC;
  50
  51         ret = pthread_rwlockattr_init(&attr);
  52         if (ret) {
  53                 log_err("pthread_rwlockattr_init: %s\n", strerror(ret));
  54                 goto err;
  55         }
  56 #ifdef CONFIG_PSHARED
  57         ret = pthread_rwlockattr_setpshared(&attr, PTHREAD_PROCESS_SHARED);
  58         if (ret) {
  59                 log_err("pthread_rwlockattr_setpshared: %s\n", strerror(ret));
  60                 goto destroy_attr;
  61         }
  62
  63         ret = pthread_rwlock_init(&lock->lock, &attr);
  64 #else
  65         ret = pthread_rwlock_init(&lock->lock, NULL);
  66 #endif
  67
  68         if (ret) {
  69                 log_err("pthread_rwlock_init: %s\n", strerror(ret));
  70                 goto destroy_attr;
  71         }
  72
  73         pthread_rwlockattr_destroy(&attr);
  74
  75         return lock;
  76 destroy_attr:
  77         pthread_rwlockattr_destroy(&attr);
  78 err:
  79         if (lock)
  80                 fio_rwlock_remove(lock);
  81         return NULL;
  82 }