linux/include/linux/sem.h
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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 */
  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__
  80#include <linux/atomic.h>
  81#include <linux/rcupdate.h>
  82#include <linux/cache.h>
  83
  84struct task_struct;
  85
  86/* One sem_array data structure for each set of semaphores in the system. */
  87struct sem_array {
  88        struct kern_ipc_perm    ____cacheline_aligned_in_smp
  89                                sem_perm;       /* permissions .. see ipc.h */
  90        time_t                  sem_otime;      /* last semop time */
  91        time_t                  sem_ctime;      /* last change time */
  92        struct sem              *sem_base;      /* ptr to first semaphore in array */
  93        struct list_head        sem_pending;    /* pending operations to be processed */
  94        struct list_head        list_id;        /* undo requests on this array */
  95        int                     sem_nsems;      /* no. of semaphores in array */
  96        int                     complex_count;  /* pending complex operations */
  97};
  98
  99#ifdef CONFIG_SYSVIPC
 100
 101struct sysv_sem {
 102        struct sem_undo_list *undo_list;
 103};
 104
 105extern int copy_semundo(unsigned long clone_flags, struct task_struct *tsk);
 106extern void exit_sem(struct task_struct *tsk);
 107
 108#else
 109
 110struct sysv_sem {
 111        /* empty */
 112};
 113
 114static inline int copy_semundo(unsigned long clone_flags, struct task_struct *tsk)
 115{
 116        return 0;
 117}
 118
 119static inline void exit_sem(struct task_struct *tsk)
 120{
 121        return;
 122}
 123#endif
 124
 125#endif /* __KERNEL__ */
 126
 127#endif /* _LINUX_SEM_H */
 128
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