Include/linux/sem.h
16904 #ifndef _LINUX_SEM_H 16905 #define _LINUX_SEM_H 16906 16907 #include <linux/ipc.h> 16908 16909 /* semop flags */ 16910 #define SEM_UNDO 0x1000 /* undo the operation on exit */ 16911 16912 /* semctl Command Definitions. */ 16913 #define GETPID 11 /* get sempid */ 16914 #define GETVAL 12 /* get semval */ 16915 #define GETALL 13 /* get all semval's */ 16916 #define GETNCNT 14 /* get semncnt */ 16917 #define GETZCNT 15 /* get semzcnt */ 16918 #define SETVAL 16 /* set semval */ 16919 #define SETALL 17 /* set all semval's */ 16920 16921 /* ipcs ctl cmds */ 16922 #define SEM_STAT 18 16923 #define SEM_INFO 19 16924 16925 /* One semid data structure for each set of semaphores in 16926 the system. */
16927 struct semid_ds { 16928 struct ipc_perm sem_perm; /* permissions; see ipc.h */ 16929 __kernel_time_t sem_otime; /* last semop time */ 16930 __kernel_time_t sem_ctime; /* last change time */ 16931 struct sem *sem_base; /* ptr to 1st sem in arr */ 16932 struct sem_queue *sem_pending; /* op to be processed */ 16933 struct sem_queue **sem_pending_last; /* last op */ 16934 struct sem_undo *undo; /* undo reqs on this arr */ 16935 unsigned short sem_nsems; /* # sems in array */ 16936 }; 16937 16938 /* semop system calls takes an array of these. */
16939 struct sembuf { 16940 unsigned short sem_num; /* sem index in array */ 16941 short sem_op; /* semaphore operation */ 16942 short sem_flg; /* operation flags */ 16943 }; 16944 16945 /* arg for semctl system calls. */ 16946 union semun { 16947 int val; /* value for SETVAL */ 16948 struct semid_ds *buf; /* buf for IPC_STAT&IPC_SET */ 16949 unsigned short *array; /* array for GETALL & SETALL */ 16950 struct seminfo *__buf; /* buffer for IPC_INFO */ 16951 void *__pad; 16952 }; 16953 16954 struct seminfo { 16955 int semmap; 16956 int semmni; 16957 int semmns; 16958 int semmnu; 16959 int semmsl; 16960 int semopm; 16961 int semume; 16962 int semusz; 16963 int semvmx; 16964 int semaem; 16965 }; 16966 16967 #define SEMMNI 128 /* ? max # of sem identifiers */ 16968 #define SEMMSL 32 /* <= 512 max semaphores per id */ 16969 #define SEMMNS (SEMMNI*SEMMSL) /* ? max sems in system*/ 16970 #define SEMOPM 32 /* ~ 100 max ops per semop call */ 16971 #define SEMVMX 32767 /* semaphore maximum value */ 16972 16973 /* unused */ 16974 #define SEMUME SEMOPM /* max undo entries per process */ 16975 #define SEMMNU SEMMNS /* # undo structures sys-wide */ 16976 #define SEMAEM (SEMVMX >> 1) /* adjust on exit max val*/ 16977 #define SEMMAP SEMMNS /* # of entries in sem map */ 16978 #define SEMUSZ 20 /* sizeof struct sem_undo */ 16979 16980 #ifdef __KERNEL__ 16981 16982 /* One sem structure for each sem in the system. */
16983 struct sem { 16984 int semval; /* current value */ 16985 int sempid; /* pid of last operation */ 16986 }; 16987 16988 /* One queue for each semaphore set in the system. */
16989 struct sem_queue { 16990 /* next entry in the queue */ 16991 struct sem_queue * next; 16992 /* previous entry in the queue, *(q->prev) == q */ 16993 struct sem_queue ** prev; 16994 /* sleeping process */ 16995 struct wait_queue * sleeper; 16996 /* undo structure */ 16997 struct sem_undo * undo; 16998 /* process id of requesting process */ 16999 int pid; 17000 /* completion status of operation */ 17001 int status; 17002 /* semaphore array for operations */ 17003 struct semid_ds * sma; 17004 /* array of pending operations */ 17005 struct sembuf * sops; 17006 /* number of operations */ 17007 int nsops; 17008 /* operation will alter semaphore */ 17009 int alter; 17010 }; 17011 17012 /* Each task has a list of undo requests. They are 17013 * executed automatically when the process exits. */
17014 struct sem_undo { 17015 /* next entry on this process */ 17016 struct sem_undo * proc_next; 17017 /* next entry on this semaphore set */ 17018 struct sem_undo * id_next; 17019 /* semaphore set identifier */ 17020 int semid; 17021 /* array of adjustments, one per semaphore */ 17022 short * semadj; 17023 }; 17024 17025 asmlinkage int sys_semget (key_t key, int nsems, 17026 int semflg); 17027 asmlinkage int sys_semop (int semid, struct sembuf *sops, 17028 unsigned nsops); 17029 asmlinkage int sys_semctl (int semid, int semnum, 17030 int cmd, union semun arg); 17031 17032 #endif /* __KERNEL__ */ 17033 17034 #endif /* _LINUX_SEM_H */
