lock_pthread.lc 1.6 KB

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  1. /* include my_lock_init */
  2. #include "unpthread.h"## 1 ##src/server/lock_pthread.c##
  3. #include <sys/mman.h>## 2 ##src/server/lock_pthread.c##
  4. static pthread_mutex_t *mptr; /* actual mutex will be in shared memory */## 3 ##src/server/lock_pthread.c##
  5. void## 4 ##src/server/lock_pthread.c##
  6. my_lock_init(char *pathname)## 5 ##src/server/lock_pthread.c##
  7. {## 6 ##src/server/lock_pthread.c##
  8. int fd;## 7 ##src/server/lock_pthread.c##
  9. pthread_mutexattr_t mattr;## 8 ##src/server/lock_pthread.c##
  10. fd = Open("/dev/zero", O_RDWR, 0);## 9 ##src/server/lock_pthread.c##
  11. mptr = Mmap(0, sizeof(pthread_mutex_t), PROT_READ | PROT_WRITE,## 10 ##src/server/lock_pthread.c##
  12. MAP_SHARED, fd, 0);## 11 ##src/server/lock_pthread.c##
  13. Close(fd);## 12 ##src/server/lock_pthread.c##
  14. Pthread_mutexattr_init(&mattr);## 13 ##src/server/lock_pthread.c##
  15. Pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED);## 14 ##src/server/lock_pthread.c##
  16. Pthread_mutex_init(mptr, &mattr);## 15 ##src/server/lock_pthread.c##
  17. }## 16 ##src/server/lock_pthread.c##
  18. /* end my_lock_init */
  19. /* include my_lock_wait */
  20. void## 17 ##src/server/lock_pthread.c##
  21. my_lock_wait()## 18 ##src/server/lock_pthread.c##
  22. {## 19 ##src/server/lock_pthread.c##
  23. Pthread_mutex_lock(mptr);## 20 ##src/server/lock_pthread.c##
  24. }## 21 ##src/server/lock_pthread.c##
  25. void## 22 ##src/server/lock_pthread.c##
  26. my_lock_release()## 23 ##src/server/lock_pthread.c##
  27. {## 24 ##src/server/lock_pthread.c##
  28. Pthread_mutex_unlock(mptr);## 25 ##src/server/lock_pthread.c##
  29. }## 26 ##src/server/lock_pthread.c##
  30. /* end my_lock_wait */