C 队列研磨错误
这个代码似乎有效。但是,以下代码会导致Valgrind错误:C 队列研磨错误,c,queue,valgrind,C,Queue,Valgrind,这个代码似乎有效。但是,以下代码会导致Valgrind错误: #include <stdlib.h> #include "queue.h" #include "queuepriv.h" #include <string.h> Queue *Queue_init(void) { Queue *q = calloc(1, sizeof(Queue)); return q; } int Queue_enqueue(Queue *q, const char *
#include <stdlib.h>
#include "queue.h"
#include "queuepriv.h"
#include <string.h>
Queue *Queue_init(void)
{
Queue *q = calloc(1, sizeof(Queue));
return q;
}
int Queue_enqueue(Queue *q, const char *id, const char *name)
{
// implement this function
struct student *new = calloc(1, sizeof(struct student));
if (strlen(id) <= 6) {
strcpy(new->id, id);
new->name = malloc(strlen(name) + 1);
strcpy(new->name, name);
new->name[strlen(name)] = '\0';
if (q->last)
q->last->next = new;
q->last = new;
q->last->next = NULL;
if (!q->first)
q->first = q->last;
return 1;
} else {
return 0;
}
}
char *Queue_firstID(Queue *q)
{
if (q && q->first)
return q->first->id;
else
return NULL;
}
char *Queue_firstName(Queue *q)
{
if (q && q->first)
return q->first->name;
else
return NULL;
}
int Queue_dequeue(Queue *q)
{
// implement this function
if (q->first) {
struct student *fst = q->first;
struct student *nxt = fst->next;
free(fst->name);
free(fst);
q->first = nxt;
if (!q->first)
q->last = NULL;
return 1;
} else {
return 0;
}
}
int Queue_drop(Queue *q, const char *id)
{
// implement this function
struct student *current = q->first;
struct student *previous = NULL;
while(current) {
if (!strcmp(id, current->id)) {
if(current == q->first) {
q->first = current->next;
} else if(current == q->last) {
q->last = previous;
q->last->next = NULL;
} else {
previous->next = current->next;
}
free(current->name);
free(current);
return 1;
}
previous = current;
current = current->next;
}
return 0;
}
void Queue_delete(Queue *q)
{
if (q) {
while(Queue_dequeue(q));
free(q);
}
}
我无法找出内存泄漏的位置,因为我想我释放了出列和丢弃函数中的所有内存
提前感谢您。在此代码中
int Queue_enqueue(Queue *q, const char *id, const char *name)
{
// implement this function
struct student *new = calloc(1, sizeof(struct student));
if (strlen(id) <= 6) {
strcpy(new->id, id);
new->name = malloc(strlen(name) + 1);
strcpy(new->name, name);
new->name[strlen(name)] = '\0';
if (q->last)
q->last->next = new;
q->last = new;
q->last->next = NULL;
if (!q->first)
q->first = q->last;
return 1;
} else {
return 0;
}
}
也许你应该把它改成:
int Queue_enqueue(Queue *q, const char *id, const char *name)
{
// implement this function
struct student *new = calloc(1, sizeof(struct student));
if (strlen(id) <= 6) {
....
} else {
free(new); // Free the memory
return 0;
}
}
int Queue\u enqueue(队列*q,常量字符*id,常量字符*name)
{
//实现这个功能
struct student*new=calloc(1,sizeof(struct student));
本代码中的if(strlen(id)
int Queue_enqueue(Queue *q, const char *id, const char *name)
{
// implement this function
struct student *new = calloc(1, sizeof(struct student));
if (strlen(id) <= 6) {
strcpy(new->id, id);
new->name = malloc(strlen(name) + 1);
strcpy(new->name, name);
new->name[strlen(name)] = '\0';
if (q->last)
q->last->next = new;
q->last = new;
q->last->next = NULL;
if (!q->first)
q->first = q->last;
return 1;
} else {
return 0;
}
}
也许你应该把它改成:
int Queue_enqueue(Queue *q, const char *id, const char *name)
{
// implement this function
struct student *new = calloc(1, sizeof(struct student));
if (strlen(id) <= 6) {
....
} else {
free(new); // Free the memory
return 0;
}
}
int Queue\u enqueue(队列*q,常量字符*id,常量字符*name)
{
//实现这个功能
struct student*new=calloc(1,sizeof(struct student));
if(strlen(id)在函数Queue\u dequeue
中,如果q->first
为空会发生什么?语句struct student*nxt=fst->next;
失败。如果q->first
为空,则不应运行struct student*nxt=fst->next
行?我如何理解,如果q->first
为空,则if语句为0接下来的行没有运行?我可能错了。在函数Queue\u dequeue
中,如果q->first
为空会发生什么?语句struct student*nxt=fst->next;
失败。如果q->first
为空,它就不应该运行struct student*nxt=fst->next
行。我怎么理解如果q->first
为空,则if语句为0,并且下一行未运行?我可能是错的。或者更好,在分配内存之前进行检查:if(strlen(id)>6)返回0;struct student*new=calloc(1,sizeof(struct student));…
或者更好,在分配内存之前进行检查:if(strlen(id)>6)返回0;struct student*new=calloc(1,sizeof(struct student));…
int Queue_enqueue(Queue *q, const char *id, const char *name)
{
// implement this function
struct student *new = calloc(1, sizeof(struct student));
if (strlen(id) <= 6) {
....
} else {
free(new); // Free the memory
return 0;
}
}