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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef _LINUX_SEM_H
2#define _LINUX_SEM_H
3
4#include <linux/ipc.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07005
6/* semop flags */
7#define SEM_UNDO 0x1000 /* undo the operation on exit */
8
9/* semctl Command Definitions. */
10#define GETPID 11 /* get sempid */
11#define GETVAL 12 /* get semval */
12#define GETALL 13 /* get all semval's */
13#define GETNCNT 14 /* get semncnt */
14#define GETZCNT 15 /* get semzcnt */
15#define SETVAL 16 /* set semval */
16#define SETALL 17 /* set all semval's */
17
18/* ipcs ctl cmds */
19#define SEM_STAT 18
20#define SEM_INFO 19
21
22/* Obsolete, used only for backwards compatibility and libc5 compiles */
23struct semid_ds {
24 struct ipc_perm sem_perm; /* permissions .. see ipc.h */
25 __kernel_time_t sem_otime; /* last semop time */
26 __kernel_time_t sem_ctime; /* last change time */
27 struct sem *sem_base; /* ptr to first semaphore in array */
28 struct sem_queue *sem_pending; /* pending operations to be processed */
29 struct sem_queue **sem_pending_last; /* last pending operation */
30 struct sem_undo *undo; /* undo requests on this array */
31 unsigned short sem_nsems; /* no. of semaphores in array */
32};
33
34/* Include the definition of semid64_ds */
35#include <asm/sembuf.h>
36
37/* semop system calls takes an array of these. */
38struct sembuf {
39 unsigned short sem_num; /* semaphore index in array */
40 short sem_op; /* semaphore operation */
41 short sem_flg; /* operation flags */
42};
43
44/* arg for semctl system calls. */
45union semun {
46 int val; /* value for SETVAL */
47 struct semid_ds __user *buf; /* buffer for IPC_STAT & IPC_SET */
48 unsigned short __user *array; /* array for GETALL & SETALL */
49 struct seminfo __user *__buf; /* buffer for IPC_INFO */
50 void __user *__pad;
51};
52
53struct seminfo {
54 int semmap;
55 int semmni;
56 int semmns;
57 int semmnu;
58 int semmsl;
59 int semopm;
60 int semume;
61 int semusz;
62 int semvmx;
63 int semaem;
64};
65
66#define SEMMNI 128 /* <= IPCMNI max # of semaphore identifiers */
67#define SEMMSL 250 /* <= 8 000 max num of semaphores per id */
68#define SEMMNS (SEMMNI*SEMMSL) /* <= INT_MAX max # of semaphores in system */
69#define SEMOPM 32 /* <= 1 000 max num of ops per semop call */
70#define SEMVMX 32767 /* <= 32767 semaphore maximum value */
71#define SEMAEM SEMVMX /* adjust on exit max value */
72
73/* unused */
74#define SEMUME SEMOPM /* max num of undo entries per process */
75#define SEMMNU SEMMNS /* num of undo structures system wide */
76#define SEMMAP SEMMNS /* # of entries in semaphore map */
77#define SEMUSZ 20 /* sizeof struct sem_undo */
78
79#ifdef __KERNEL__
David Woodhouse8ffbc752006-04-25 14:55:13 +010080#include <asm/atomic.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070081
Tim Schmielau8c65b4a2005-11-07 00:59:43 -080082struct task_struct;
83
Linus Torvalds1da177e2005-04-16 15:20:36 -070084/* One semaphore structure for each semaphore in the system. */
85struct sem {
86 int semval; /* current value */
87 int sempid; /* pid of last operation */
88};
89
90/* One sem_array data structure for each set of semaphores in the system. */
91struct sem_array {
92 struct kern_ipc_perm sem_perm; /* permissions .. see ipc.h */
Mike Waychison19b49462005-09-06 15:17:10 -070093 int sem_id;
Linus Torvalds1da177e2005-04-16 15:20:36 -070094 time_t sem_otime; /* last semop time */
95 time_t sem_ctime; /* last change time */
96 struct sem *sem_base; /* ptr to first semaphore in array */
97 struct sem_queue *sem_pending; /* pending operations to be processed */
98 struct sem_queue **sem_pending_last; /* last pending operation */
99 struct sem_undo *undo; /* undo requests on this array */
100 unsigned long sem_nsems; /* no. of semaphores in array */
101};
102
103/* One queue for each sleeping process in the system. */
104struct sem_queue {
105 struct sem_queue * next; /* next entry in the queue */
106 struct sem_queue ** prev; /* previous entry in the queue, *(q->prev) == q */
107 struct task_struct* sleeper; /* this process */
108 struct sem_undo * undo; /* undo structure */
109 int pid; /* process id of requesting process */
110 int status; /* completion status of operation */
111 struct sem_array * sma; /* semaphore array for operations */
112 int id; /* internal sem id */
113 struct sembuf * sops; /* array of pending operations */
114 int nsops; /* number of operations */
115 int alter; /* does the operation alter the array? */
116};
117
118/* Each task has a list of undo requests. They are executed automatically
119 * when the process exits.
120 */
121struct sem_undo {
122 struct sem_undo * proc_next; /* next entry on this process */
123 struct sem_undo * id_next; /* next entry on this semaphore set */
124 int semid; /* semaphore set identifier */
125 short * semadj; /* array of adjustments, one per semaphore */
126};
127
128/* sem_undo_list controls shared access to the list of sem_undo structures
129 * that may be shared among all a CLONE_SYSVSEM task group.
130 */
131struct sem_undo_list {
132 atomic_t refcnt;
133 spinlock_t lock;
134 struct sem_undo *proc_list;
135};
136
137struct sysv_sem {
138 struct sem_undo_list *undo_list;
139};
140
141#ifdef CONFIG_SYSVIPC
142
143extern int copy_semundo(unsigned long clone_flags, struct task_struct *tsk);
144extern void exit_sem(struct task_struct *tsk);
145
146#else
147static inline int copy_semundo(unsigned long clone_flags, struct task_struct *tsk)
148{
149 return 0;
150}
151
152static inline void exit_sem(struct task_struct *tsk)
153{
154 return;
155}
156#endif
157
158#endif /* __KERNEL__ */
159
160#endif /* _LINUX_SEM_H */