1 /* 2 * Copyright (c) 1988 University of Utah. 3 * Copyright (c) 1990, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * the Systems Programming Group of the University of Utah Computer 8 * Science Department. 9 * 10 * %sccs.include.proprietary.c% 11 * 12 * @(#)shm.h 8.2 (Berkeley) 09/22/93 13 */ 14 15 /* 16 * SVID compatible shm.h file 17 */ 18 #ifndef _SHM_H_ 19 #define _SHM_H_ 20 21 #ifdef KERNEL 22 #include "ipc.h" 23 #else 24 #include <sys/ipc.h> 25 #endif 26 27 struct shmid_ds { 28 struct ipc_perm shm_perm; /* operation perms */ 29 int shm_segsz; /* size of segment (bytes) */ 30 ushort shm_cpid; /* pid, creator */ 31 ushort shm_lpid; /* pid, last operation */ 32 short shm_nattch; /* no. of current attaches */ 33 time_t shm_atime; /* last attach time */ 34 time_t shm_dtime; /* last detach time */ 35 time_t shm_ctime; /* last change time */ 36 void *shm_handle; /* internal handle for shm segment */ 37 }; 38 39 /* 40 * System 5 style catch-all structure for shared memory constants that 41 * might be of interest to user programs. Do we really want/need this? 42 */ 43 struct shminfo { 44 int shmmax; /* max shared memory segment size (bytes) */ 45 int shmmin; /* min shared memory segment size (bytes) */ 46 int shmmni; /* max number of shared memory identifiers */ 47 int shmseg; /* max shared memory segments per process */ 48 int shmall; /* max amount of shared memory (pages) */ 49 }; 50 51 /* internal "mode" bits */ 52 #define SHM_ALLOC 01000 /* segment is allocated */ 53 #define SHM_DEST 02000 /* segment will be destroyed on last detach */ 54 55 /* SVID required constants (same values as system 5) */ 56 #define SHM_RDONLY 010000 /* read-only access */ 57 #define SHM_RND 020000 /* round attach address to SHMLBA boundary */ 58 59 /* implementation constants */ 60 #define SHMLBA CLBYTES /* segment low boundary address multiple */ 61 #define SHMMMNI 512 /* maximum value for shminfo.shmmni */ 62 63 #ifdef KERNEL 64 struct shmid_ds *shmsegs; 65 struct shminfo shminfo; 66 #endif 67 68 #endif /* !_SHM_H_ */ 69