sysdeps/unix/sysv/linux/bits/shm.h

   1 /* Copyright (C) 1995-2019 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #ifndef _SYS_SHM_H
  19 # error "Never include <bits/shm.h> directly; use <sys/shm.h> instead."
  20 #endif
  21
  22 #include <bits/types.h>
  23 #include <bits/wordsize.h>
  24 #include <bits/shmlba.h>
  25 #include <bits/shm-pad.h>
  26
  27 /* Permission flag for shmget.  */
  28 #define SHM_R           0400            /* or S_IRUGO from <linux/stat.h> */
  29 #define SHM_W           0200            /* or S_IWUGO from <linux/stat.h> */
  30
  31 /* Flags for `shmat'.  */
  32 #define SHM_RDONLY      010000          /* attach read-only else read-write */
  33 #define SHM_RND         020000          /* round attach address to SHMLBA */
  34 #define SHM_REMAP       040000          /* take-over region on attach */
  35 #define SHM_EXEC        0100000         /* execution access */
  36
  37 /* Commands for `shmctl'.  */
  38 #define SHM_LOCK        11              /* lock segment (root only) */
  39 #define SHM_UNLOCK      12              /* unlock segment (root only) */
  40
  41 __BEGIN_DECLS
  42
  43 /* Type to count number of attaches.  */
  44 typedef __syscall_ulong_t shmatt_t;
  45
  46 #if __SHM_PAD_BEFORE_TIME
  47 # define __SHM_PAD_TIME(NAME, RES)                              \
  48   unsigned long int __glibc_reserved ## RES; __time_t NAME
  49 #elif __SHM_PAD_AFTER_TIME
  50 # define __SHM_PAD_TIME(NAME, RES)                              \
  51   __time_t NAME; unsigned long int __glibc_reserved ## RES
  52 #else
  53 # define __SHM_PAD_TIME(NAME, RES)              \
  54   __time_t NAME
  55 #endif
  56
  57 /* Data structure describing a shared memory segment.  */
  58 struct shmid_ds
  59   {
  60     struct ipc_perm shm_perm;           /* operation permission struct */
  61 #if !__SHM_SEGSZ_AFTER_TIME
  62     size_t shm_segsz;                   /* size of segment in bytes */
  63 #endif
  64     __SHM_PAD_TIME (shm_atime, 1);      /* time of last shmat() */
  65     __SHM_PAD_TIME (shm_dtime, 2);      /* time of last shmdt() */
  66     __SHM_PAD_TIME (shm_ctime, 3);      /* time of last change by shmctl() */
  67 #if __SHM_PAD_BETWEEN_TIME_AND_SEGSZ
  68     unsigned long int __glibc_reserved4;
  69 #endif
  70 #if __SHM_SEGSZ_AFTER_TIME
  71     size_t shm_segsz;                   /* size of segment in bytes */
  72 #endif
  73     __pid_t shm_cpid;                   /* pid of creator */
  74     __pid_t shm_lpid;                   /* pid of last shmop */
  75     shmatt_t shm_nattch;                /* number of current attaches */
  76     __syscall_ulong_t __glibc_reserved5;
  77     __syscall_ulong_t __glibc_reserved6;
  78   };
  79
  80 #ifdef __USE_MISC
  81
  82 /* ipcs ctl commands */
  83 # define SHM_STAT       13
  84 # define SHM_INFO       14
  85 # define SHM_STAT_ANY   15
  86
  87 /* shm_mode upper byte flags */
  88 # define SHM_DEST       01000   /* segment will be destroyed on last detach */
  89 # define SHM_LOCKED     02000   /* segment will not be swapped */
  90 # define SHM_HUGETLB    04000   /* segment is mapped via hugetlb */
  91 # define SHM_NORESERVE  010000  /* don't check for reservations */
  92
  93 struct  shminfo
  94   {
  95     __syscall_ulong_t shmmax;
  96     __syscall_ulong_t shmmin;
  97     __syscall_ulong_t shmmni;
  98     __syscall_ulong_t shmseg;
  99     __syscall_ulong_t shmall;
 100     __syscall_ulong_t __glibc_reserved1;
 101     __syscall_ulong_t __glibc_reserved2;
 102     __syscall_ulong_t __glibc_reserved3;
 103     __syscall_ulong_t __glibc_reserved4;
 104   };
 105
 106 struct shm_info
 107   {
 108     int used_ids;
 109     __syscall_ulong_t shm_tot;  /* total allocated shm */
 110     __syscall_ulong_t shm_rss;  /* total resident shm */
 111     __syscall_ulong_t shm_swp;  /* total swapped shm */
 112     __syscall_ulong_t swap_attempts;
 113     __syscall_ulong_t swap_successes;
 114   };
 115
 116 #endif /* __USE_MISC */
 117
 118 __END_DECLS