问ctypes和内存泄漏

EN

#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#define MAXFRAGMENTS 4000000

typedef struct {
    uint64_t FirstFragmentTimestamp;
} fragment_t;

typedef struct {
    fragment_t** fragments;
} bts_t;


bts_t* initialize() {
    uint32_t i;
    bts_t* bts;
    bts = (bts_t *) malloc(sizeof(bts_t));
    bts->fragments= (fragment_t **) malloc(sizeof(bts_t *)*MAXFRAGMENTS);
    for(i=0;i<MAXFRAGMENTS;i++) {
        (bts->fragments)[i]=(fragment_t *) malloc(sizeof(fragment_t));
        (bts->fragments)[i]->FirstFragmentTimestamp = 0;
    }
    return bts;
}

int fr(bts_t *bts)
{
    uint32_t i;
    if ( bts != NULL ) {
        for(i=0;i<MAXFRAGMENTS;i++) {
            free(bts -> fragments[i]);
        }
        free(bts->fragments);
    }
    free(bts);
  return 1;
}


int main() {
}

from ctypes import *
import time

class fragment(Structure):
    _fields_=[("FirstFragmentTimestamp",c_ulong)]

class bts(Structure):
    _fields_=[("fragments",POINTER(POINTER(fragment)))]


bts_pointer=POINTER(bts)
bts_library=CDLL("test.so")
bts_initialize = bts_library.initialize
bts_initialize.restype = bts_pointer
bts_free = bts_library.fr
m = bts_pointer()
m = bts_initialize()
bts_free(m)
print 'done'
time.sleep(20)