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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 | #ifndef _LINUX_SEM_H #define _LINUX_SEM_H #include <linux/ipc.h> /* semop flags */ #define SEM_UNDO 0x1000 /* undo the operation on exit */ /* semctl Command Definitions. */ #define GETPID 11 /* get sempid */ #define GETVAL 12 /* get semval */ #define GETALL 13 /* get all semval's */ #define GETNCNT 14 /* get semncnt */ #define GETZCNT 15 /* get semzcnt */ #define SETVAL 16 /* set semval */ #define SETALL 17 /* set all semval's */ /* ipcs ctl cmds */ #define SEM_STAT 18 #define SEM_INFO 19 /* One semid data structure for each set of semaphores in the system. */ struct semid_ds { struct ipc_perm sem_perm; /* permissions .. see ipc.h */ __kernel_time_t sem_otime; /* last semop time */ __kernel_time_t sem_ctime; /* last change time */ struct sem *sem_base; /* ptr to first semaphore in array */ struct sem_queue *sem_pending; /* pending operations to be processed */ struct sem_queue **sem_pending_last; /* last pending operation */ struct sem_undo *undo; /* undo requests on this array */ unsigned short sem_nsems; /* no. of semaphores in array */ }; /* semop system calls takes an array of these. */ struct sembuf { unsigned short sem_num; /* semaphore index in array */ short sem_op; /* semaphore operation */ short sem_flg; /* operation flags */ }; /* arg for semctl system calls. */ union semun { int val; /* value for SETVAL */ struct semid_ds *buf; /* buffer for IPC_STAT & IPC_SET */ unsigned short *array; /* array for GETALL & SETALL */ struct seminfo *__buf; /* buffer for IPC_INFO */ void *__pad; }; struct seminfo { int semmap; int semmni; int semmns; int semmnu; int semmsl; int semopm; int semume; int semusz; int semvmx; int semaem; }; #define SEMMNI 128 /* ? max # of semaphore identifiers */ #define SEMMSL 32 /* <= 512 max num of semaphores per id */ #define SEMMNS (SEMMNI*SEMMSL) /* ? max # of semaphores in system */ #define SEMOPM 32 /* ~ 100 max num of ops per semop call */ #define SEMVMX 32767 /* semaphore maximum value */ /* unused */ #define SEMUME SEMOPM /* max num of undo entries per process */ #define SEMMNU SEMMNS /* num of undo structures system wide */ #define SEMAEM (SEMVMX >> 1) /* adjust on exit max value */ #define SEMMAP SEMMNS /* # of entries in semaphore map */ #define SEMUSZ 20 /* sizeof struct sem_undo */ #ifdef __KERNEL__ /* One semaphore structure for each semaphore in the system. */ struct sem { int semval; /* current value */ int sempid; /* pid of last operation */ }; /* One queue for each semaphore set in the system. */ struct sem_queue { struct sem_queue * next; /* next entry in the queue */ struct sem_queue ** prev; /* previous entry in the queue, *(q->prev) == q */ struct wait_queue * sleeper; /* sleeping process */ struct sem_undo * undo; /* undo structure */ int pid; /* process id of requesting process */ int status; /* completion status of operation */ struct semid_ds * sma; /* semaphore array for operations */ struct sembuf * sops; /* array of pending operations */ int nsops; /* number of operations */ }; /* Each task has a list of undo requests. They are executed automatically * when the process exits. */ struct sem_undo { struct sem_undo * proc_next; /* next entry on this process */ struct sem_undo * id_next; /* next entry on this semaphore set */ int semid; /* semaphore set identifier */ short * semadj; /* array of adjustments, one per semaphore */ }; asmlinkage int sys_semget (key_t key, int nsems, int semflg); asmlinkage int sys_semop (int semid, struct sembuf *sops, unsigned nsops); asmlinkage int sys_semctl (int semid, int semnum, int cmd, union semun arg); #endif /* __KERNEL__ */ #endif /* _LINUX_SEM_H */ |