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