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1 : #ifndef _LINUX_SEM_H
2 : #define _LINUX_SEM_H
3 :
4 : #include <linux/ipc.h>
5 :
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 */
23 : struct 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. */
38 : struct 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. */
45 : union 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 :
53 : struct 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__
80 : #include <asm/atomic.h>
81 : #include <linux/rcupdate.h>
82 :
83 : struct task_struct;
84 :
85 : /* One semaphore structure for each semaphore in the system. */
86 : struct sem {
87 : int semval; /* current value */
88 : int sempid; /* pid of last operation */
89 : struct list_head sem_pending; /* pending single-sop operations */
90 : };
91 :
92 : /* One sem_array data structure for each set of semaphores in the system. */
93 : struct sem_array {
94 : struct kern_ipc_perm sem_perm; /* permissions .. see ipc.h */
95 : time_t sem_otime; /* last semop time */
96 : time_t sem_ctime; /* last change time */
97 : struct sem *sem_base; /* ptr to first semaphore in array */
98 : struct list_head sem_pending; /* pending operations to be processed */
99 : struct list_head list_id; /* undo requests on this array */
100 : int sem_nsems; /* no. of semaphores in array */
101 : int complex_count; /* pending complex operations */
102 : };
103 :
104 : /* One queue for each sleeping process in the system. */
105 : struct sem_queue {
106 : struct list_head simple_list; /* queue of pending operations */
107 : struct list_head list; /* queue of pending operations */
108 : struct task_struct *sleeper; /* this process */
109 : struct sem_undo *undo; /* undo structure */
110 : int pid; /* process id of requesting process */
111 : int status; /* completion status of operation */
112 : struct sembuf *sops; /* array of pending operations */
113 : int nsops; /* number of operations */
114 : int alter; /* does the operation alter the array? */
115 : };
116 1 :
117 : /* Each task has a list of undo requests. They are executed automatically
118 : * when the process exits.
119 : */
120 : struct sem_undo {
121 : struct list_head list_proc; /* per-process list: all undos from one process. */
122 : /* rcu protected */
123 : struct rcu_head rcu; /* rcu struct for sem_undo() */
124 : struct sem_undo_list *ulp; /* sem_undo_list for the process */
125 : struct list_head list_id; /* per semaphore array list: all undos for one array */
126 : int semid; /* semaphore set identifier */
127 : short * semadj; /* array of adjustments, one per semaphore */
128 : };
129 1 :
130 : /* sem_undo_list controls shared access to the list of sem_undo structures
131 : * that may be shared among all a CLONE_SYSVSEM task group.
132 : */
133 : struct sem_undo_list {
134 : atomic_t refcnt;
135 : spinlock_t lock;
136 : struct list_head list_proc;
137 : };
138 1 :
139 : struct sysv_sem {
140 : struct sem_undo_list *undo_list;
141 : };
142 :
143 : #ifdef CONFIG_SYSVIPC
144 :
145 : extern int copy_semundo(unsigned long clone_flags, struct task_struct *tsk);
146 : extern void exit_sem(struct task_struct *tsk);
147 :
148 : #else
149 : static inline int copy_semundo(unsigned long clone_flags, struct task_struct *tsk)
150 : {
151 : return 0;
152 : }
153 :
154 : static inline void exit_sem(struct task_struct *tsk)
155 : {
156 : return;
157 : }
158 : #endif
159 :
160 : #endif /* __KERNEL__ */
161 :
162 : #endif /* _LINUX_SEM_H */
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