1 #include <stdlib.h> 2 #include <stdio.h> 3 #include "../../config.h" 4 #if defined(HAVE_MALLINFO) 5 #include <malloc.h> 6 #endif 7 8 #define BIGINCREASE 32000 9 int debug = 0; 10 11 void stats(char *msg) 12 { 13 #if defined(HAVE_MALLINFO) 14 struct mallinfo mallinfo_result; 15 mallinfo_result = mallinfo(); 16 #endif 17 18 /* from /usr/include/malloc.h */ 19 printf("%s\n", msg); 20 21 #if defined(HAVE_MALLINFO) 22 printf("%10d int arena; /* non-mmapped space allocated from system */\n", mallinfo_result.arena); 23 printf("%10d int ordblks; /* number of free chunks */\n", mallinfo_result.ordblks); 24 printf("%10d int smblks; /* number of fastbin blocks */\n", mallinfo_result.smblks); 25 printf("%10d int hblks; /* number of mmapped regions */\n", mallinfo_result.hblks); 26 printf("%10d int hblkhd; /* space in mmapped regions */\n", mallinfo_result.hblkhd); 27 printf("%10d int usmblks; /* maximum total allocated space */\n", mallinfo_result.usmblks); 28 printf("%10d int fsmblks; /* space available in freed fastbin blocks */\n", mallinfo_result.fsmblks); 29 printf("%10d int uordblks; /* total allocated space */\n", mallinfo_result.uordblks); 30 printf("%10d int fordblks; /* total free space */\n", mallinfo_result.fordblks); 31 printf("%10d int keepcost; /* top-most, releasable (via malloc_trim) space */\n", mallinfo_result.keepcost); 32 printf("\n"); 33 #endif 34 } 35 36 int main(int argc, char *argv[]) 37 { 38 39 char *big = NULL; 40 41 char *newbig; 42 int malloc_failure = 0; 43 unsigned long bigsize = 8; // current size of the (reallocated) big block. 44 int i; 45 int loop; 46 47 // two optional arguments: [nr of loop] [debug] 48 if (argc > 1) 49 loop = atoi(argv[1]); 50 else 51 loop = 3000; 52 53 if (argc > 2) 54 debug = 1; 55 56 bigsize += BIGINCREASE; 57 big = malloc (bigsize); 58 if (big == NULL) 59 printf ("failure %d could not allocate size %lu\n", 60 ++malloc_failure, bigsize); 61 if (debug) 62 printf("big 0x%p\n", big); 63 64 for (i = 0; i < loop; i++) 65 { 66 bigsize += BIGINCREASE; 67 newbig = malloc(bigsize); 68 if (newbig == NULL) 69 printf ("failure %d could not allocate size %lu\n", 70 ++malloc_failure, bigsize); 71 free (big); 72 big = newbig; 73 if (debug) 74 printf("big 0x%p\n", big); 75 } 76 77 printf ("after %d loops, last size block requested %lu\n", loop, bigsize); 78 // verify if superblock fragmentation occurred 79 // We consider that an arena of up to 3 times more than bigsize is ok. 80 { 81 #if defined(HAVE_MALLINFO) 82 struct mallinfo mallinfo_result; 83 mallinfo_result = mallinfo(); 84 // Under valgrind, hblkhd is 0 : all the space is in arena. 85 // Under native linux, some space is counted hblkhd. 86 if (malloc_failure > 0) 87 printf ("%d mallocs failed, below output is doubful\n", malloc_failure); 88 if (mallinfo_result.arena + mallinfo_result.hblkhd > 3 * bigsize) 89 printf("unexpected heap fragmentation %lu\n", 90 (unsigned long) mallinfo_result.arena 91 + (unsigned long) mallinfo_result.hblkhd); 92 else 93 #endif 94 printf("reasonable heap usage\n"); 95 } 96 97 if (debug) 98 stats ("before freeing last block"); 99 free (big); 100 if (debug) 101 stats ("after freeing last block"); 102 103 return 0; 104 } 105
