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 *buf; /* buffer for IPC_STAT & IPC_SET */ 48 unsigned short *array; /* array for GETALL & SETALL */ 49 struct seminfo *__buf; /* buffer for IPC_INFO */ 50 void *__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 81/* One semaphore structure for each semaphore in the system. */ 82struct sem { 83 int semval; /* current value */ 84 int sempid; /* pid of last operation */ 85}; 86 87/* One sem_array data structure for each set of semaphores in the system. */ 88struct sem_array { 89 struct kern_ipc_perm 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 sem_queue *sem_pending; /* pending operations to be processed */ 94 struct sem_queue **sem_pending_last; /* last pending operation */ 95 struct sem_undo *undo; /* undo requests on this array */ 96 unsigned long sem_nsems; /* no. of semaphores in array */ 97}; 98 99/* One queue for each sleeping process in the system. */ 100struct sem_queue { 101 struct sem_queue * next; /* next entry in the queue */ 102 struct sem_queue ** prev; /* previous entry in the queue, *(q->prev) == q */ 103 struct task_struct* sleeper; /* this process */ 104 struct sem_undo * undo; /* undo structure */ 105 int pid; /* process id of requesting process */ 106 int status; /* completion status of operation */ 107 struct sem_array * sma; /* semaphore array for operations */ 108 int id; /* internal sem id */ 109 struct sembuf * sops; /* array of pending operations */ 110 int nsops; /* number of operations */ 111 int alter; /* operation will alter semaphore */ 112}; 113 114/* Each task has a list of undo requests. They are executed automatically 115 * when the process exits. 116 */ 117struct sem_undo { 118 struct sem_undo * proc_next; /* next entry on this process */ 119 struct sem_undo * id_next; /* next entry on this semaphore set */ 120 int semid; /* semaphore set identifier */ 121 short * semadj; /* array of adjustments, one per semaphore */ 122}; 123 124asmlinkage long sys_semget (key_t key, int nsems, int semflg); 125asmlinkage long sys_semop (int semid, struct sembuf *sops, unsigned nsops); 126asmlinkage long sys_semctl (int semid, int semnum, int cmd, union semun arg); 127asmlinkage long sys_semtimedop (int semid, struct sembuf *sops, 128 unsigned nsops, const struct timespec *timeout); 129 130#endif /* __KERNEL__ */ 131 132#endif /* _LINUX_SEM_H */ 133
