diff options
Diffstat (limited to 'nptl/descr.h')
| -rw-r--r-- | nptl/descr.h | 45 |
1 files changed, 36 insertions, 9 deletions
diff --git a/nptl/descr.h b/nptl/descr.h index 80251b920b..f89d3240da 100644 --- a/nptl/descr.h +++ b/nptl/descr.h @@ -102,6 +102,15 @@ struct xid_command }; +/* Data structure used by the kernel to find robust futexes. */ +struct robust_list_head +{ + void *list; + long int futex_offset; + void *list_op_pending; +}; + + /* Thread descriptor data structure. */ struct pthread { @@ -136,25 +145,43 @@ struct pthread /* List of robust mutexes the thread is holding. */ #ifdef __PTHREAD_MUTEX_HAVE_PREV - __pthread_list_t robust_list; + void *robust_prev; + struct robust_list_head robust_head; + + /* The list above is strange. It is basically a double linked list + but the pointer to the next/previous element of the list points + in the middle of the object, the __next element. Whenever + casting to __pthread_list_t we need to adjust the pointer + first. */ +# define QUEUE_PTR_ADJUST (offsetof (__pthread_list_t, __next)) # define ENQUEUE_MUTEX(mutex) \ do { \ - __pthread_list_t *next = THREAD_GETMEM (THREAD_SELF, robust_list.__next); \ - next->__prev = &mutex->__data.__list; \ - mutex->__data.__list.__next = next; \ - mutex->__data.__list.__prev = &THREAD_SELF->robust_list; \ - THREAD_SETMEM (THREAD_SELF, robust_list.__next, &mutex->__data.__list); \ + __pthread_list_t *next = (THREAD_GETMEM (THREAD_SELF, robust_head.list) \ + - QUEUE_PTR_ADJUST); \ + next->__prev = (void *) &mutex->__data.__list.__next; \ + mutex->__data.__list.__next = (void *) &next->__next; \ + mutex->__data.__list.__prev = (void *) &THREAD_SELF->robust_head; \ + THREAD_SETMEM (THREAD_SELF, robust_head.list, \ + &mutex->__data.__list.__next); \ } while (0) # define DEQUEUE_MUTEX(mutex) \ do { \ - mutex->__data.__list.__next->__prev = mutex->__data.__list.__prev; \ - mutex->__data.__list.__prev->__next = mutex->__data.__list.__next; \ + __pthread_list_t *next = (__pthread_list_t *) \ + ((char *) mutex->__data.__list.__next - QUEUE_PTR_ADJUST); \ + next->__prev = mutex->__data.__list.__prev; \ + __pthread_list_t *prev = (__pthread_list_t *) \ + ((char *) mutex->__data.__list.__prev - QUEUE_PTR_ADJUST); \ + prev->__next = mutex->__data.__list.__next; \ mutex->__data.__list.__prev = NULL; \ mutex->__data.__list.__next = NULL; \ } while (0) #else - __pthread_slist_t robust_list; + union + { + __pthread_slist_t robust_list; + struct robust_list_head robust_head; + }; # define ENQUEUE_MUTEX(mutex) \ do { \ |