| 1 | /* Emulation of getpagesize() for systems that need it. */ |
| 2 | |
| 3 | /* |
| 4 | |
| 5 | NAME |
| 6 | |
| 7 | getpagesize -- return the number of bytes in page of memory |
| 8 | |
| 9 | SYNOPSIS |
| 10 | |
| 11 | int getpagesize (void) |
| 12 | |
| 13 | DESCRIPTION |
| 14 | |
| 15 | Returns the number of bytes in a page of memory. This is the |
| 16 | granularity of many of the system memory management routines. |
| 17 | No guarantee is made as to whether or not it is the same as the |
| 18 | basic memory management hardware page size. |
| 19 | |
| 20 | BUGS |
| 21 | |
| 22 | Is intended as a reasonable replacement for systems where this |
| 23 | is not provided as a system call. The value of 4096 may or may |
| 24 | not be correct for the systems where it is returned as the default |
| 25 | value. |
| 26 | |
| 27 | */ |
| 28 | |
| 29 | #ifndef VMS |
| 30 | |
| 31 | #include "config.h" |
| 32 | |
| 33 | #include <sys/types.h> |
| 34 | #ifdef HAVE_SYS_PARAM_H |
| 35 | #include <sys/param.h> |
| 36 | #endif |
| 37 | |
| 38 | #undef GNU_OUR_PAGESIZE |
| 39 | #if defined (HAVE_SYSCONF) && defined (HAVE_UNISTD_H) |
| 40 | #include <unistd.h> |
| 41 | #ifdef _SC_PAGESIZE |
| 42 | #define GNU_OUR_PAGESIZE sysconf(_SC_PAGESIZE) |
| 43 | #endif |
| 44 | #endif |
| 45 | |
| 46 | #ifndef GNU_OUR_PAGESIZE |
| 47 | # ifdef PAGESIZE |
| 48 | # define GNU_OUR_PAGESIZE PAGESIZE |
| 49 | # else /* no PAGESIZE */ |
| 50 | # ifdef EXEC_PAGESIZE |
| 51 | # define GNU_OUR_PAGESIZE EXEC_PAGESIZE |
| 52 | # else /* no EXEC_PAGESIZE */ |
| 53 | # ifdef NBPG |
| 54 | # define GNU_OUR_PAGESIZE (NBPG * CLSIZE) |
| 55 | # ifndef CLSIZE |
| 56 | # define CLSIZE 1 |
| 57 | # endif /* CLSIZE */ |
| 58 | # else /* no NBPG */ |
| 59 | # ifdef NBPC |
| 60 | # define GNU_OUR_PAGESIZE NBPC |
| 61 | # else /* no NBPC */ |
| 62 | # define GNU_OUR_PAGESIZE 4096 /* Just punt and use reasonable value */ |
| 63 | # endif /* NBPC */ |
| 64 | # endif /* NBPG */ |
| 65 | # endif /* EXEC_PAGESIZE */ |
| 66 | # endif /* PAGESIZE */ |
| 67 | #endif /* GNU_OUR_PAGESIZE */ |
| 68 | |
| 69 | int |
| 70 | getpagesize () |
| 71 | { |
| 72 | return (GNU_OUR_PAGESIZE); |
| 73 | } |
| 74 | |
| 75 | #else /* VMS */ |
| 76 | |
| 77 | #if 0 /* older distributions of gcc-vms are missing <syidef.h> */ |
| 78 | #include <syidef.h> |
| 79 | #endif |
| 80 | #ifndef SYI$_PAGE_SIZE /* VMS V5.4 and earlier didn't have this yet */ |
| 81 | #define SYI$_PAGE_SIZE 4452 |
| 82 | #endif |
| 83 | extern unsigned long lib$getsyi(const unsigned short *,...); |
| 84 | |
| 85 | int getpagesize () |
| 86 | { |
| 87 | long pagsiz = 0L; |
| 88 | unsigned short itmcod = SYI$_PAGE_SIZE; |
| 89 | |
| 90 | (void) lib$getsyi (&itmcod, (void *) &pagsiz); |
| 91 | if (pagsiz == 0L) |
| 92 | pagsiz = 512L; /* VAX default */ |
| 93 | return (int) pagsiz; |
| 94 | } |
| 95 | |
| 96 | #endif /* VMS */ |