重载operator new而不重载operator delete

Question

大家好

我有下面的简单代码.我为我的类定义了operator new而没有operator delete.根据valgrind --leak-check=yes PROGRAM_NAME我有一个不匹配,即我正在new[]为数组分配使用,但我正在使用简单delete的非数组解除分配.你知道为什么吗？

关心AFG

#include<string>
#include<new>


class CA{
public:
CA(){
    std::cout << "*created CA*";
}   

~CA(){
    std::cout << "*deleted*";
}

void* operator new( std::size_t aSize ){
    std::cout << "*MY NEW*";
    void* storage = std::malloc( aSize );
    if( !storage )
    {
        std::exception ex;
        throw ex;
    }
    return storage;
}};

int main(int argc, char** argv){
CA* p = new CA();
delete p;   
return 0;

}

==2767== Mismatched free() / delete / delete []
==2767==    at 0x4024851: operator delete(void*) (vg_replace_malloc.c:387)
==2767==    by 0x80488BD: main (operator_new_test.cpp:54)
==2767==  Address 0x42d3028 is 0 bytes inside a block of size 1 alloc'd
==2767==    at 0x4024F20: malloc (vg_replace_malloc.c:236)
==2767==    by 0x80489A4: CA::operator new(unsigned int) (operator_new_test.cpp:18)
==2767==    by 0x804887B: main (operator_new_test.cpp:53)

Answer 1

您的重载运算符new使用malloc,但随后您使用普通的C++ delete运算符解除分配.这是一个经典错误.如果分配malloc,则必须始终取消分配free.如果分配new,则必须始终取消分配delete(或者delete[]在数组的情况下).

你需要重载delete操作员并让它调用free().