| #ifndef _LINUX_SEM_H |
| #define _LINUX_SEM_H |
| |
| #include <linux/atomic.h> |
| #include <linux/rcupdate.h> |
| #include <linux/cache.h> |
| #include <linux/time64.h> |
| #include <uapi/linux/sem.h> |
| |
| struct task_struct; |
| |
| /* One semaphore structure for each semaphore in the system. */ |
| struct sem { |
| int semval; /* current value */ |
| /* |
| * PID of the process that last modified the semaphore. For |
| * Linux, specifically these are: |
| * - semop |
| * - semctl, via SETVAL and SETALL. |
| * - at task exit when performing undo adjustments (see exit_sem). |
| */ |
| int sempid; |
| spinlock_t lock; /* spinlock for fine-grained semtimedop */ |
| struct list_head pending_alter; /* pending single-sop operations */ |
| /* that alter the semaphore */ |
| struct list_head pending_const; /* pending single-sop operations */ |
| /* that do not alter the semaphore*/ |
| time_t sem_otime; /* candidate for sem_otime */ |
| } ____cacheline_aligned_in_smp; |
| |
| /* One sem_array data structure for each set of semaphores in the system. */ |
| struct sem_array { |
| struct kern_ipc_perm sem_perm; /* permissions .. see ipc.h */ |
| time64_t sem_ctime; /* create/last semctl() time */ |
| struct list_head pending_alter; /* pending operations */ |
| /* that alter the array */ |
| struct list_head pending_const; /* pending complex operations */ |
| /* that do not alter semvals */ |
| struct list_head list_id; /* undo requests on this array */ |
| int sem_nsems; /* no. of semaphores in array */ |
| int complex_count; /* pending complex operations */ |
| unsigned int use_global_lock;/* >0: global lock required */ |
| |
| struct sem sems[]; |
| }; |
| |
| #ifdef CONFIG_SYSVIPC |
| |
| struct sysv_sem { |
| struct sem_undo_list *undo_list; |
| }; |
| |
| extern int copy_semundo(unsigned long clone_flags, struct task_struct *tsk); |
| extern void exit_sem(struct task_struct *tsk); |
| |
| #else |
| |
| struct sysv_sem { |
| /* empty */ |
| }; |
| |
| static inline int copy_semundo(unsigned long clone_flags, struct task_struct *tsk) |
| { |
| return 0; |
| } |
| |
| static inline void exit_sem(struct task_struct *tsk) |
| { |
| return; |
| } |
| #endif |
| |
| #endif /* _LINUX_SEM_H */ |