Question

因此，基本上，我有一个函数，它具有大学结构并将其填充为学生。一切正常！大学返回主大学后，所有值都存储在主大学内。
然后，当我尝试释放它时（主要），它由于某种原因而在braude.students[2].name上出错，没有其他原因了。
例外是：CtrlsValidHeapPointer（block）。
为什么要释放所有其他动态分配的名称，而不释放这个？

university getStudentInfo(FILE * file) // Definition of the getStudentInfo function
{ // This function reads student information from a file
  // and updates a university with this information using a pointer
    int i = 1, j;
    char name[99]; // A temporary name to hold the student's name.
    university tempUni; // A temporary university to hold values
    Stud * temp = (Stud*)malloc(sizeof(Stud)); // Allocating memory
                                              //  for an array of students

    if (temp == NULL) // In case there wasn't enough space 
        Error_Msg("Couldn't allocate enough memory.");

    while (getInfo(file, name, &temp[i - 1]) == 8)
    // Using getInfo==8, because in each row, there are 8 variables to scan
    {
        temp[i - 1].name = (char*)malloc(sizeof(char)*strlen(name) + 1);
        // Allocating memory for the current element's name.

        if (temp[i - 1].name == NULL) // In case there wasn't enough space, terminate
            Error_Msg("Couldn't allocate enough memory.");
        strcpy(temp[i - 1].name, name);
        // If there was, copy the name from "name" to the current student's name.

        i++; // Increase i by one to have space in memory for one more student
        temp = (Stud*)realloc(temp, i * sizeof(Stud));
        // Realloc temp, to make more space for one more student.

        if (temp == NULL) // In case there wasn't enough space, terminate.
            Error_Msg("Couldn't allocate enough memory.");
    }

    tempUni.students = (Stud*)malloc(sizeof(temp));
    // Allocating memory for students of the university, with the size of temp

    if (tempUni.students == NULL)
        // In case there wasn't enough space, terminate.
        Error_Msg("Couldn't allocate enough memory.");

    tempUni.students->marks[5] = '\0'; // Making the last mark in the string \0
    tempUni.students = temp; // Let the temporary university array of students be temp 
    tempUni.studentCount = i - 1; // How many students
    return tempUni; // Update the pointed university to have the same values as tempUni
}

但是当我释放main中动态分配的内存时，像这样：

free(braude.students[0].name);
    free(braude.students[1].name);
            free(braude.students[2].name); // Crashes here???
            free(braude.students[3].name);
            free(braude.students);

Answer 1

此行

tempUni.students = (Stud*)malloc(sizeof(temp));

仅为一个指针分配内存。该代码不容易理解，但也许应该

tempUni.students = malloc(i * sizeof(Stud));

无法释放仅一个动态分配的元素

1 个答案: