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         pthread_rwlock_destroy(&lock->lock);
  32         munmap((void *) lock, sizeof(*lock));
  33 }
  34
  35 struct fio_rwlock *fio_rwlock_init(void)
  36 {
  37         struct fio_rwlock *lock;
  38         pthread_rwlockattr_t attr;
  39         int ret;
  40
  41         lock = (void *) mmap(NULL, sizeof(struct fio_rwlock),
  42                                 PROT_READ | PROT_WRITE,
  43                                 OS_MAP_ANON | MAP_SHARED, -1, 0);
  44         if (lock == MAP_FAILED) {
  45                 perror("mmap rwlock");
  46                 lock = NULL;
  47                 goto err;
  48         }
  49
  50         lock->magic = FIO_RWLOCK_MAGIC;
  51
  52         ret = pthread_rwlockattr_init(&attr);
  53         if (ret) {
  54                 log_err("pthread_rwlockattr_init: %s\n", strerror(ret));
  55                 goto err;
  56         }
  57 #ifdef CONFIG_PSHARED
  58         ret = pthread_rwlockattr_setpshared(&attr, PTHREAD_PROCESS_SHARED);
  59         if (ret) {
  60                 log_err("pthread_rwlockattr_setpshared: %s\n", strerror(ret));
  61                 goto destroy_attr;
  62         }
  63
  64         ret = pthread_rwlock_init(&lock->lock, &attr);
  65 #else
  66         ret = pthread_rwlock_init(&lock->lock, NULL);
  67 #endif
  68
  69         if (ret) {
  70                 log_err("pthread_rwlock_init: %s\n", strerror(ret));
  71                 goto destroy_attr;
  72         }
  73
  74         pthread_rwlockattr_destroy(&attr);
  75
  76         return lock;
  77 destroy_attr:
  78         pthread_rwlockattr_destroy(&attr);
  79 err:
  80         if (lock)
  81                 fio_rwlock_remove(lock);
  82         return NULL;
  83 }