diff options
Diffstat (limited to 'linux/src/include/linux/sem.h')
| -rw-r--r-- | linux/src/include/linux/sem.h | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/linux/src/include/linux/sem.h b/linux/src/include/linux/sem.h new file mode 100644 index 0000000..0eb1d02 --- /dev/null +++ b/linux/src/include/linux/sem.h @@ -0,0 +1,112 @@ +#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 */ + +/* One semid data structure for each set of semaphores in the system. */ +struct semid_ds { + struct ipc_perm sem_perm; /* permissions .. see ipc.h */ + time_t sem_otime; /* last semop time */ + 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 */ + ushort sem_nsems; /* no. of semaphores in array */ +}; + +/* semop system calls takes an array of these. */ +struct sembuf { + ushort 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 */ + ushort *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 { + short semval; /* current value */ + short sempid; /* pid of last operation */ +}; + +/* ipcs ctl cmds */ +#define SEM_STAT 18 +#define SEM_INFO 19 + +/* 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 */ |