diff options
Diffstat (limited to 'include/linux/sem.h')
| -rw-r--r-- | include/linux/sem.h | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/include/linux/sem.h b/include/linux/sem.h new file mode 100644 index 00000000000..2d8516be9fd --- /dev/null +++ b/include/linux/sem.h @@ -0,0 +1,157 @@ +#ifndef _LINUX_SEM_H +#define _LINUX_SEM_H + +#include <linux/ipc.h> +#include <asm/atomic.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 + +/* Obsolete, used only for backwards compatibility and libc5 compiles */ +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 */ +}; + +/* Include the definition of semid64_ds */ +#include <asm/sembuf.h> + +/* 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 __user *buf; /* buffer for IPC_STAT & IPC_SET */ + unsigned short __user *array; /* array for GETALL & SETALL */ + struct seminfo __user *__buf; /* buffer for IPC_INFO */ + void __user *__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 /* <= IPCMNI max # of semaphore identifiers */ +#define SEMMSL 250 /* <= 8 000 max num of semaphores per id */ +#define SEMMNS (SEMMNI*SEMMSL) /* <= INT_MAX max # of semaphores in system */ +#define SEMOPM 32 /* <= 1 000 max num of ops per semop call */ +#define SEMVMX 32767 /* <= 32767 semaphore maximum value */ +#define SEMAEM SEMVMX /* adjust on exit max value */ + +/* unused */ +#define SEMUME SEMOPM /* max num of undo entries per process */ +#define SEMMNU SEMMNS /* num of undo structures system wide */ +#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 sem_array data structure for each set of semaphores in the system. */ +struct sem_array { + struct kern_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 */ + unsigned long sem_nsems; /* no. of semaphores in array */ +}; + +/* One queue for each sleeping process 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 task_struct* sleeper; /* this process */ + struct sem_undo * undo; /* undo structure */ + int pid; /* process id of requesting process */ + int status; /* completion status of operation */ + struct sem_array * sma; /* semaphore array for operations */ + int id; /* internal sem id */ + struct sembuf * sops; /* array of pending operations */ + int nsops; /* number of operations */ + int alter; /* does the operation alter the array? */ +}; + +/* 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 */ +}; + +/* sem_undo_list controls shared access to the list of sem_undo structures + * that may be shared among all a CLONE_SYSVSEM task group. + */ +struct sem_undo_list { + atomic_t refcnt; + spinlock_t lock; + struct sem_undo *proc_list; +}; + +struct sysv_sem { + struct sem_undo_list *undo_list; +}; + +#ifdef CONFIG_SYSVIPC + +extern int copy_semundo(unsigned long clone_flags, struct task_struct *tsk); +extern void exit_sem(struct task_struct *tsk); + +#else +static inline int copy_semundo(unsigned long clone_flags, struct task_struct *tsk) +{ + return 0; +} + +static inline void exit_sem(struct task_struct *tsk) +{ + return; +} +#endif + +#endif /* __KERNEL__ */ + +#endif /* _LINUX_SEM_H */ |