include/linux/sem.h

   1 #ifndef _LINUX_SEM_H
   2 #define _LINUX_SEM_H
   3
   4 #include <linux/atomic.h>
   5 #include <linux/rcupdate.h>
   6 #include <linux/cache.h>
   7 #include <uapi/linux/sem.h>
   8
   9 struct task_struct;
  10
  11 /* One sem_array data structure for each set of semaphores in the system. */
  12 struct sem_array {
  13         struct kern_ipc_perm    ____cacheline_aligned_in_smp
  14                                 sem_perm;       /* permissions .. see ipc.h */
  15         time_t                  sem_ctime;      /* last change time */
  16         struct sem              *sem_base;      /* ptr to first semaphore in array */
  17         struct list_head        pending_alter;  /* pending operations */
  18                                                 /* that alter the array */
  19         struct list_head        pending_const;  /* pending complex operations */
  20                                                 /* that do not alter semvals */
  21         struct list_head        list_id;        /* undo requests on this array */
  22         int                     sem_nsems;      /* no. of semaphores in array */
  23         int                     complex_count;  /* pending complex operations */
  24 };
  25
  26 #ifdef CONFIG_SYSVIPC
  27
  28 struct sysv_sem {
  29         struct sem_undo_list *undo_list;
  30 };
  31
  32 extern int copy_semundo(unsigned long clone_flags, struct task_struct *tsk);
  33 extern void exit_sem(struct task_struct *tsk);
  34
  35 #else
  36
  37 struct sysv_sem {
  38         /* empty */
  39 };
  40
  41 static inline int copy_semundo(unsigned long clone_flags, struct task_struct *tsk)
  42 {
  43         return 0;
  44 }
  45
  46 static inline void exit_sem(struct task_struct *tsk)
  47 {
  48         return;
  49 }
  50 #endif
  51
  52 #endif /* _LINUX_SEM_H */