0
다음 코드는 작동하지만 메모리 누수가 발생합니다. 프로그램이 연결된 목록과 동적 메모리 기능을 사용하고 있습니다. 프로그램은 명령 행 인수로서 .txt 파일을 제외합니다.내 C 프로그램에서 메모리 누수가
예제 파일 :
제이콥 밀러 832,323,244 21
의 출력
톰 대런 8,931,701,830 19
폴 미첼 여기 329,797,231 20
Valgrind의
==5742== HEAP SUMMARY:
==5742== in use at exit: 324 bytes in 9 blocks
==5742== total heap usage: 11 allocs, 2 frees, 908 bytes allocated
==5742==
==5742== 52 bytes in 1 blocks are definitely lost in loss record 2 of 4
==5742== at 0x4A0610C: malloc (vg_replace_malloc.c:195)
==5742== by 0x400A2C: student_record_allocate (new.c:106)
==5742== by 0x4007EB: main (new.c:46)
==5742==
==5742== 272 (16 direct, 256 indirect) bytes in 1 blocks are definitely lost in loss record 4 of 4
==5742== at 0x4A0610C: malloc (vg_replace_malloc.c:195)
==5742== by 0x400A1E: student_record_allocate (new.c:104)
==5742== by 0x4008D1: parseFile (new.c:74)
==5742== by 0x400803: main (new.c:47)
==5742==
==5742== LEAK SUMMARY:
==5742== definitely lost: 68 bytes in 2 blocks
==5742== indirectly lost: 256 bytes in 7 blocks
==5742== possibly lost: 0 bytes in 0 blocks
==5742== still reachable: 0 bytes in 0 blocks
==5742== suppressed: 0 bytes in 0 blocks
==5742==
==5742== For counts of detected and suppressed errors, rerun with: -v
==5742== ERROR SUMMARY: 66 errors from 21 contexts (suppressed: 4 from 4)
여기에 코드 스 니펫에 문제가 있습니다.
void parseFile(char* filename, struct student_record_node** head)
{
FILE *fp;
student_record_node *sn;
fp = fopen(filename, "r");
if (!fp) {
fprintf(stderr, "Can't Open file %s\n", filename);
exit(EXIT_FAILURE);
}
while(!feof(fp)) {
sn = student_record_allocate();
fscanf(fp, "%20s", sn->record_->first_name_);
fscanf(fp, "%20s", sn->record_->last_name_);
fscanf(fp, "%d", &(sn->record_->student_id_));
fscanf(fp, "%d", &(sn->record_->student_age_));
appendNode(*head, sn);
}
fclose(fp);
}
void printNode(struct student_record_node* node)
{
printf("\nstruct student_record_node:\n");
if (node) {
printf("\tstudent first name: %s\n",node->record_->first_name_);
printf("\tstudent second name: %s\n",node->record_->last_name_);
printf("\tstudent id: %d\n", node->record_->student_id_);
printf("\tstudent age: %d", node->record_->student_age_);
}
}
struct student_record_node* student_record_allocate()
{
student_record_node *newNode=NULL;
student_record *newRecord=NULL;
newNode = (student_record_node *)malloc(sizeof(student_record_node));
newRecord = (student_record *)malloc(sizeof(student_record));
newNode->record_ = newRecord;
newNode->next_ = NULL;
return newNode;
free(newNode->record_);
}
{
free(node->record_);
free(node->next_);
}
나는이 방법 여기
void freeNodeList(struct student_record_node* head)
{
student_record_node *tmp;
while(tmp != NULL) {
tmp=head;
head=head->next_;
free(tmp);
}
head=NULL;
}
을 통해 위 확보하고 나의 전체 코드입니다
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
struct student_record
{
int student_id_;
int student_age_;
char first_name_[21];
char last_name_[21];
}s;
struct student_record_node
{
struct student_record* record_;
struct student_record_node* next_;
};
typedef struct student_record student_record;
typedef struct student_record_node student_record_node;
void parseFile(char* filename, struct student_record_node** head);
void printNode(struct student_record_node* node);
struct student_record_node* student_record_allocate();
void student_record_node_deallocate(struct student_record_node* node);
void sortByAge(struct student_record_node** recordsHead);
void sortById(struct student_record_node** recordsHead);
void swap(struct student_record_node** node1, struct student_record_node** node2);
void freeNodeList(struct student_record_node* head);
void appendNode(struct student_record_node* head, struct student_record_node* newNode);
void printNodeList(struct student_record_node* head);
int main(int argc, char **argv)
{
student_record_node *head;
if (argc != 2) {
fprintf(stderr, "Error: expected input file");
exit(EXIT_FAILURE);
}
/* student_record *newRecord=NULL;
recordsHead->record_ = newRecord;
recordsHead->next_ = NULL;
*/
head = student_record_allocate();
parseFile(argv[1], &head);
printf("Before sorting...");
printNodeList(head);
printf("Sorting by age...");
sortByAge(&head);
printNodeList(head);
printf("Sorting by id...");
sortById(&head);
printNodeList(head);
freeNodeList(head);
free(head);
return 0;
}
void parseFile(char* filename, struct student_record_node** head)
{
FILE *fp;
student_record_node *sn;
fp = fopen(filename, "r");
if (!fp) {
fprintf(stderr, "Can't Open file %s\n", filename);
exit(EXIT_FAILURE);
}
while(!feof(fp)) {
sn = student_record_allocate();
fscanf(fp, "%20s", sn->record_->first_name_);
fscanf(fp, "%20s", sn->record_->last_name_);
fscanf(fp, "%d", &(sn->record_->student_id_));
fscanf(fp, "%d", &(sn->record_->student_age_));
appendNode(*head, sn);
}
fclose(fp);
}
void printNode(struct student_record_node* node)
{
printf("\nstruct student_record_node:\n");
if (node) {
printf("\tstudent first name: %s\n",node->record_->first_name_);
printf("\tstudent second name: %s\n",node->record_->last_name_);
printf("\tstudent id: %d\n", node->record_->student_id_);
printf("\tstudent age: %d", node->record_->student_age_);
}
}
struct student_record_node* student_record_allocate()
{
student_record_node *newNode=NULL;
student_record *newRecord=NULL;
newNode = (student_record_node *)malloc(sizeof(student_record_node));
newRecord = (student_record *)malloc(sizeof(student_record));
newNode->record_ = newRecord;
newNode->next_ = NULL;
return newNode;
free(newNode->record_);
}
{
free(node->record_);
free(node->next_);
}
void sortByAge(struct student_record_node **recordsHead)
{
int swapped, i;
struct student_record_node *ptr1;
struct student_record_node *lptr = NULL;
do
{
swapped = 0;
ptr1 = *recordsHead;
while (ptr1->next_ != lptr)
{
if (ptr1->record_->student_age_ > ptr1->next_->record_->student_age_)
{
swap(&ptr1, &ptr1->next_);
swapped = 1;
}
ptr1 = ptr1->next_;
}
lptr = ptr1;
}
while (swapped);
}
void sortById(struct student_record_node** recordsHead)
{
int swapped, i;
struct student_record_node *ptr1;
struct student_record_node *lptr = NULL;
do
{
swapped = 0;
ptr1 = *recordsHead;
while (ptr1->next_ != lptr)
{
if (ptr1->record_->student_id_ > ptr1->next_->record_->student_id_)
{
swap(&ptr1, &ptr1->next_);
swapped = 1;
}
ptr1 = ptr1->next_;
}
lptr = ptr1;
}
while (swapped);
}
void swap(struct student_record_node** node1, struct student_record_node** node2)
{
student_record_node *tmp, *n1, *n2;
n1 = *node1;
n2 = *node2;
tmp->record_= n1->record_;
n1->record_= n2->record_;
n2->record_ = tmp->record_;
}
void freeNodeList(struct student_record_node* head)
{
student_record_node *tmp;
while(tmp != NULL) {
tmp=head;
head=head->next_;
free(tmp);
}
head=NULL;
}
void appendNode(struct student_record_node* head, struct
student_record_node* newNode)
{
student_record_node *prev, *next;
if(head == NULL) {
head = newNode;
return;
}
next = head;
while(next != NULL) {
prev = next;
next = next->next_;
}
prev->next_ = newNode;
}
void printNodeList(struct student_record_node* head)
{
student_record_node *tmp = head;
while(tmp != NULL) {
tmp = tmp->next_;
printNode(tmp);
}
}
SO에있는 모든 링크드 목록 게시물의 약 절반은 '머리'의 로컬 복사본을 변경하고 그 기능에서 벗어날 것을 기대하면서 동일한 문제가 있습니다. 그건 그렇지 않을거야. 새 헤드를 함수 결과로 반환하거나 이중 포인터를 전달하여이 작업을 수행하는 모든 코드를 수정합니다. – ThingyWotsit