内存泄露检测之ccmalloc

ccmalloc是常用的内存检测工具之一，适用于Linux环境。

使用说明

官方例子：

例1：

#include <stdio.h>

void Leak(char *inStr)
{
  char *str = (char *) malloc(strlen(inStr));
  memcpy(str, inStr, strlen(inStr));
}

char *AvoidLeak(char *inStr)
{
  char *str = (char *) malloc(strlen(inStr));
  memcpy(str, inStr, strlen(inStr));
  return str;
}

int main()
{
  char *str;

  Leak("This leaks 19 bytes");
  str = AvoidLeak("This is not a 26 byte leak");
  free(str);
  str = AvoidLeak("12 byte leak");
  exit(0);
}

结果：

　　

.--------------------------------------------------------------------------.
|================ ccmalloc-0.3.8 (C) 1997-2001 Armin Biere ================|
+--------------------------------------------------------------------------+
| executable       = /home/faculty/donahoo/public_html/tools/ccmalloc/a.out |
| startup file     = .ccmalloc (but not found)                             |
| log file         = stderr                                                |
| start time       = Wed Dec 19 09:57:16 2001                              |
| operating system = Linux 2.4.2-2smp i686 on earth.ecs.baylor.edu         |
+--------------------------------------------------------------------------+
| only-count        = 0            keep-deallocated-data = 0               |
| check-interval    = 0            check-free-space      = 0               |
| check-start       = 0            file-info             = 1               |
| chain-length      = 0            additional-line       = 1               |
| check-underwrites = 0            print-addresses       = 0               |
| check-overwrites  = 0            print-on-one-line     = 0               |
| sort-by-wasted    = 1            sort-by-size          = 1               |
| # only-log-chain  = 0            continue              = 0               |
| # dont-log-chain  = 0            statistics            = 0               |
| debug             = 0            library-chains        = 0               |
| load-dynlibs      = 0            align-8-byte          = 0               |
| only-wasting-alloc= 1                                                    |
`--------------------------------------------------------------------------'

.---------------.
|ccmalloc report|
=======================================================
| total # of|   allocated | deallocated |     garbage |
+-----------+-------------+-------------+-------------+
|      bytes|          57 |          26 |          31 |
+-----------+-------------+-------------+-------------+
|allocations|           3 |           1 |           2 |
+-----------------------------------------------------+
| number of checks: 1                                 |
| number of counts: 4                                 |
| retrieving function names for addresses ... done.   |
| reading file info from gdb ... done.                |
| sorting by number of not reclaimed bytes ... done.  |
| number of call chains: 2                            |
| number of ignored call chains: 0                    |
| number of reported call chains: 2                   |
| number of internal call chains: 2                   |
| number of library call chains: 0                    |
=======================================================
|
* 61.3% = 19 Bytes of garbage allocated in 1 allocation
|       |
|       |       0x40047306 in <???>
|       |
|       |       0x080493eb in <main>
|       |                  at test1.c:20
|       |
|       |       0x0804935c in <Leak>
|       |                  at test1.c:5
|       |
|       `-----> 0x08052fb7 in <malloc>
|                          at src/wrapper.c:318
|        
* 38.7% = 12 Bytes of garbage allocated in 1 allocation
|       |
|       |       0x40047306 in <???>
|       |
|       |       0x0804941e in <main>
|       |                  at test1.c:23
|       |
|       |       0x080493a4 in <AvoidLeak>
|       |                  at test1.c:11
|       |
|       `-----> 0x08052fb7 in <malloc>
|                          at src/wrapper.c:318
|        
`------------------------------------------------------

　　

没看明白，继续再看例2

例2：

/* Test from creator of ccmalloc (http://iseran.ira.uka.de/~armin/ccmalloc/) */
#include <stdio.h>
#include <stdlib.h>

static char *mkstr(char *s) 
{ 
  return strcpy(malloc(strlen(s)+1), s);
}

void f() {
  mkstr("asdfasdf");
}

void g()
{
  int i;
  char *a[100];

  for(i=0; i<100; i++)
    a[i] = mkstr("in f");
  
  free(a[2]);
  free(a[0]);
}

int main()
{
  char *a = mkstr("Hallo"), *b;

  (void) mkstr("Test");

  f();

  b = mkstr("Test");

  g();

  a[6]=0;

  free(b);
  free(a);

  exit(0);
  return 1;
}

使用CCMalloc结果：

.--------------------------------------------------------------------------.
|================ ccmalloc-0.3.8 (C) 1997-2001 Armin Biere ================|
+--------------------------------------------------------------------------+
| executable       = /home/faculty/donahoo/public_html/tools/ccmalloc/a.out |
| startup file     = .ccmalloc (but not found)                             |
| log file         = stderr                                                |
| start time       = Wed Dec 19 10:05:49 2001                              |
| operating system = Linux 2.4.2-2smp i686 on earth.ecs.baylor.edu         |
+--------------------------------------------------------------------------+
| only-count        = 0            keep-deallocated-data = 0               |
| check-interval    = 0            check-free-space      = 0               |
| check-start       = 0            file-info             = 1               |
| chain-length      = 0            additional-line       = 1               |
| check-underwrites = 0            print-addresses       = 0               |
| check-overwrites  = 0            print-on-one-line     = 0               |
| sort-by-wasted    = 1            sort-by-size          = 1               |
| # only-log-chain  = 0            continue              = 0               |
| # dont-log-chain  = 0            statistics            = 0               |
| debug             = 0            library-chains        = 0               |
| load-dynlibs      = 0            align-8-byte          = 0               |
| only-wasting-alloc= 1                                                    |
`--------------------------------------------------------------------------'

.---------------.
|ccmalloc report|
=======================================================
| total # of|   allocated | deallocated |     garbage |
+-----------+-------------+-------------+-------------+
|      bytes|         525 |          21 |         504 |
+-----------+-------------+-------------+-------------+
|allocations|         104 |           4 |         100 |
+-----------------------------------------------------+
| number of checks: 1                                 |
| number of counts: 108                               |
| retrieving function names for addresses ... done.   |
| reading file info from gdb ... done.                |
| sorting by number of not reclaimed bytes ... done.  |
| number of call chains: 3                            |
| number of ignored call chains: 0                    |
| number of reported call chains: 3                   |
| number of internal call chains: 3                   |
| number of library call chains: 0                    |
=======================================================
|
* 97.2% = 490 Bytes of garbage allocated in 98 allocations
|       |
|       |       0x40047306 in <???>
|       |
|       |       0x0804944a in <main>
|       |                  at test2.c:36
|       |
|       |       0x080493b9 in <g>
|       |                  at test2.c:20
|       |
|       |       0x08049360 in <mkstr>
|       |                  at test2.c:7
|       |
|       `-----> 0x08053007 in <malloc>
|                          at src/wrapper.c:318
|        
|  1.8% = 9 Bytes of garbage allocated in 1 allocation
|       |
|       |       0x40047306 in <???>
|       |
|       |       0x08049430 in <main>
|       |                  at test2.c:32
|       |
|       |       0x0804938b in <f>
|       |                  at test2.c:11
|       |
|       |       0x08049360 in <mkstr>
|       |                  at test2.c:7
|       |
|       `-----> 0x08053007 in <malloc>
|                          at src/wrapper.c:318
|        
|  0.10% = 5 Bytes of garbage allocated in 1 allocation
|       |
|       |       0x40047306 in <???>
|       |
|       |       0x08049428 in <main>
|       |                  at test2.c:30
|       |
|       |       0x08049360 in <mkstr>
|       |                  at test2.c:7
|       |
|       `-----> 0x08053007 in <malloc>
|                          at src/wrapper.c:318
|        
`------------------------------------------------------