#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 /* 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__ #include <asm/atomic.h> #include <linux/rcupdate.h> struct task_struct; /* 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 list_head sem_pending; /* pending operations to be processed */ struct list_head list_id; /* 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 list_head list; /* queue of pending operations */ 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 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 list_head list_proc; /* per-process list: all undos from one process. */ /* rcu protected */ struct rcu_head rcu; /* rcu struct for sem_undo() */ struct sem_undo_list *ulp; /* sem_undo_list for the process */ struct list_head list_id; /* per semaphore array list: all undos for one array */ 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 list_head list_proc; }; 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 */