| fitzhardinge | 1a30304 | 2003-12-22 08:48:50 +0000 | [diff] [blame] | 1 | #define _GNU_SOURCE |
| 2 | #include <sys/mman.h> |
| 3 | #include <stdio.h> |
| 4 | #include <stdlib.h> |
| 5 | |
| 6 | static char *mkmap(unsigned sz) |
| 7 | { |
| 8 | static char *map; |
| 9 | static unsigned mapsz; |
| 10 | char *p; |
| 11 | |
| 12 | if (map != NULL) |
| 13 | munmap(map, mapsz); |
| 14 | |
| 15 | p = (char *)mmap(0, sz, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); |
| 16 | |
| 17 | if (p == (char *)-1) { |
| 18 | perror("mmap"); |
| 19 | exit(1); |
| 20 | } |
| 21 | |
| 22 | map = p; |
| 23 | mapsz = sz; |
| 24 | |
| 25 | return p; |
| 26 | } |
| 27 | |
| 28 | |
| 29 | int main() |
| 30 | { |
| 31 | char *np; |
| 32 | char *p; |
| 33 | |
| 34 | p = mkmap(1024*1024); |
| 35 | np = mremap(p, 1024*1024, 256*1024, 0); /* shrink, fixed */ |
| 36 | if (np == (char *)-1) |
| 37 | perror("mremap(shrink, fixed)"); |
| 38 | if (np != p) |
| 39 | fprintf(stderr, "shrink, nomove: p=%p np=%p: shrink moved?!\n", |
| 40 | p, np); |
| 41 | if (np != (char *)-1) |
| 42 | munmap(np, 256*1024); |
| 43 | |
| 44 | p = mkmap(1024*1024); |
| 45 | np = mremap(p, 1024*1024, 256*1024, MREMAP_MAYMOVE); /* shrink, maymove */ |
| 46 | if (np == (char *)-1) |
| 47 | perror("mremap(shrink, maymove)"); |
| 48 | if (np != p) |
| 49 | fprintf(stderr, "shrink, maymove: p=%p np=%p: shrink moved?!\n", |
| 50 | p, np); |
| 51 | if (np != (char *)-1) |
| 52 | munmap(np, 256*1024); |
| 53 | |
| 54 | p = mkmap(1024*1024); |
| 55 | np = mremap(p, 1024*1024, 2048*1024, 0); /* grow, fixed */ |
| 56 | if (np == (char *)-1) |
| 57 | perror("mremap(grow, fixed)"); |
| 58 | if (np != p) |
| 59 | fprintf(stderr, "grow, nomove: p=%p np=%p: shrink moved?!\n", |
| 60 | p, np); |
| 61 | if (np != (char *)-1) |
| 62 | munmap(np, 2048*1024); |
| 63 | |
| 64 | p = mkmap(1024*1024); |
| 65 | np = mremap(p, 1024*1024, 2048*1024, MREMAP_MAYMOVE); /* grow, maymove */ |
| 66 | if (np == (char *)-1) |
| 67 | perror("mremap(grow, maymove)"); |
| 68 | if (np != p) |
| 69 | fprintf(stderr, "grow, maymove: p=%p np=%p: shrink moved?!\n", |
| 70 | p, np); |
| 71 | if (np != (char *)-1) |
| 72 | munmap(np, 2048*1024); |
| 73 | |
| 74 | p = mkmap(1024*1024); |
| 75 | munmap(p+512*1024, 4096); |
| 76 | np = mremap(p, 512*1024, 1024*1024, 0); /* grow, nomove, constrained */ |
| 77 | if (np == (char *)-1) |
| 78 | perror("mremap(grow, nomove, constrained)"); |
| 79 | else if (np == p) |
| 80 | fprintf(stderr, "grow, maymove, constrained: p=%p np=%p (managed to grow without moving?!)\n", |
| 81 | p, np); |
| 82 | if (np != (char *)-1) |
| 83 | munmap(np, 1024*1024); |
| 84 | |
| 85 | p = mkmap(1024*1024); |
| 86 | munmap(p+512*1024, 4096); |
| 87 | |
| 88 | np = mremap(p, 512*1024, 1024*1024, MREMAP_MAYMOVE); /* grow, maymove, constrained */ |
| 89 | if (np == (char *)-1) |
| 90 | perror("mremap(grow, maymove, constrained)"); |
| 91 | if (np == p) |
| 92 | fprintf(stderr, "grow, maymove, constrained: p=%p np=%p (managed to grow without moving?!)\n", |
| 93 | p, np); |
| 94 | if (np != (char *)-1) |
| 95 | munmap(np, 1024*1024); |
| 96 | |
| 97 | return 0; |
| 98 | } |