https://perl5.git.perl.org / metaconfig.git / blame
| Commit | Line | Data |
|---|---|---|
| 959f3c4c JH |
1 | ?RCS: $Id: sbrksmart.U,v 3.0.1.2 1995/01/11 15:35:41 ram Exp $ |
| 2 | ?RCS: | |
| 3 | ?RCS: Copyright (c) 1991-1993, Raphael Manfredi | |
| 4 | ?RCS: | |
| 5 | ?RCS: You may redistribute only under the terms of the Artistic Licence, | |
| 6 | ?RCS: as specified in the README file that comes with the distribution. | |
| 7 | ?RCS: You may reuse parts of this distribution only within the terms of | |
| 8 | ?RCS: that same Artistic Licence; a copy of which may be found at the root | |
| 9 | ?RCS: of the source tree for dist 3.0. | |
| 10 | ?RCS: | |
| 11 | ?RCS: $Log: sbrksmart.U,v $ | |
| 12 | ?RCS: Revision 3.0.1.2 1995/01/11 15:35:41 ram | |
| 13 | ?RCS: patch45: now sets sbrksmart to undef explicitely when lacking sbrk() | |
| 14 | ?RCS: patch45: forgot a cast when using return value from sbrk() | |
| 15 | ?RCS: | |
| 16 | ?RCS: Revision 3.0.1.1 1994/01/24 14:16:45 ram | |
| 17 | ?RCS: patch16: created | |
| 18 | ?RCS: | |
| 19 | ?MAKE:sbrksmart: cat d_sbrk Compile rm | |
| 20 | ?MAKE: -pick add $@ %< | |
| 21 | ?S:sbrksmart: | |
| 22 | ?S: This variable conditionally defines HAS_SMART_SBRK if the sbrk() | |
| 23 | ?S: routine honors a negative argument to lower the break value. | |
| 24 | ?S:. | |
| 25 | ?C:HAS_SMART_SBRK: | |
| 26 | ?C: This symbol is defined when the sbrk() system call may be used with | |
| 27 | ?C: a negative argument to lower the break value, therefore releasing | |
| 28 | ?C: core to the system. If not, you'd probably be better off using the | |
| 29 | ?C: mmap() system call. | |
| 30 | ?C:. | |
| 31 | ?H:#$sbrksmart HAS_SMART_SBRK /**/ | |
| 32 | ?H:. | |
| 33 | ?T:dumb | |
| 34 | : see if sbrk can release core to the kernel | |
| 35 | echo " " | |
| 36 | case "$d_sbrk" in | |
| 37 | "$define") | |
| 38 | echo "Let's see if your sbrk() is smart enough to release core..." >&4 | |
| 39 | $cat > sbrk.c <<'EOC' | |
| 40 | #define INC 256 /* Small enough to be less than a page size */ | |
| 41 | ||
| 42 | int main() | |
| 43 | { | |
| 44 | char *obrk = (char *) sbrk(0); | |
| 45 | char *nbrk; | |
| 46 | ||
| 47 | nbrk = (char *) sbrk(INC); | |
| 48 | if (nbrk == (char *) -1) | |
| 49 | exit(1); /* Not enough memory */ | |
| 50 | if (nbrk != obrk) | |
| 51 | exit(2); /* Unreliable sbrk() */ | |
| 52 | nbrk = (char *) sbrk(-INC); | |
| 53 | if (nbrk == (char *) -1) | |
| 54 | exit(3); /* May have understood negative arg as huge positive */ | |
| 55 | if (obrk != (char *) sbrk(0)) | |
| 56 | exit(4); /* Not smart, definitely */ | |
| 57 | ||
| 58 | exit(0); /* Ok */ | |
| 59 | } | |
| 60 | EOC | |
| 61 | sbrksmart="$undef" | |
| 62 | dumb='-- assuming dumb sbrk().' | |
| 63 | set sbrk | |
| 64 | if eval $compile_ok; then | |
| 65 | ./sbrk >/dev/null 2>&1 | |
| 66 | case $? in | |
| 67 | 0) sbrksmart="$define" | |
| 68 | echo "Yes, it can be used with negative values." ;; | |
| 69 | 1) echo "Sorry, not enough memory $dumb" ;; | |
| 70 | 2) echo "No it's not, and besides it seems to be buggy..." ;; | |
| 71 | 3) echo "No, it fails with negative values." ;; | |
| 72 | 4) echo "Nope, your sbrk() is too dumb." ;; | |
| 73 | *) echo "Err... Unexpected result $dumb" ;; | |
| 74 | esac | |
| 75 | else | |
| 76 | echo "(Could not compile test program $dumb)" | |
| 77 | fi | |
| 78 | ;; | |
| 79 | *) | |
| 80 | echo "Since you don't have sbrk(), let's forget about the smart test!" | |
| 81 | sbrksmart="$undef" | |
| 82 | ;; | |
| 83 | esac | |
| 84 | $rm -f sbrk sbrk.* core | |
| 85 |