无效的读取大小为8，但没有内存泄漏

Invalid read of size 8, but no memory leaks

本文关键字：内存 泄漏 读取 小为 无效      更新时间：2023-10-16

我正在做c++ Kafka客户端https://github.com/edenhill/librdkafka/blob/master/examples/rdkafka_example.cpp。

在我的KafkaProducer类中，有几个指针。

RdKafka::Conf* m_conf;
RdKafka::Conf* m_tconf;
RdKafka::Producer* m_producer;
RdKafka::Topic* m_topic;
m_conf = RdKafka::Conf::create(RdKafka::Conf::CONF_GLOBAL);
m_producer = RdKafka::Producer::create(m_conf, m_errstr);
m_tconf = RdKafka::Conf::create(RdKafka::Conf::CONF_TOPIC);
m_topic = RdKafka::Topic::create(m_producer, m_topic_str, m_tconf, m_errstr);

在析构函数中，我做了以下操作:

if(m_producer)
    delete m_producer;
if(m_topic)
    delete m_topic;
if(m_tconf)
    delete m_tconf;
if(m_conf)
    delete m_conf;

我用valgrind检查我的程序，没有泄漏。但是"无效阅读"也存在一些问题。一些内存被释放了两次。但我不知道是哪段记忆。以下是valgrind输出的一部分。

==4627== 2 errors in context 10 of 12:
==4627== Invalid read of size 8
==4627==    at 0x52887A7: RdKafka::log_cb_trampoline(rd_kafka_s const*, int, char const*, char const*) (in /usr/lib/x86_64-linux-gnu/librdkafka++.so.1)
==4627==    by 0x5493C8F: ??? (in /usr/lib/x86_64-linux-gnu/librdkafka.so.1)
==4627==    by 0x549A531: ??? (in /usr/lib/x86_64-linux-gnu/librdkafka.so.1)
==4627==    by 0x54A0219: ??? (in /usr/lib/x86_64-linux-gnu/librdkafka.so.1)
==4627==    by 0x54A1A13: ??? (in /usr/lib/x86_64-linux-gnu/librdkafka.so.1)
==4627==    by 0x506C181: start_thread (pthread_create.c:312)
==4627==    by 0x5EE747C: clone (clone.S:111)
==4627==  Address 0x68df7f8 is 24 bytes inside a block of size 64 free'd
==4627==    at 0x4C2C2BC: operator delete(void*) (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==4627==    by 0x407E90: KafkaProducer::disconnect() (kafkaproducer.cpp:57)
==4627==    by 0x407D29: KafkaProducer::~KafkaProducer() (kafkaproducer.cpp:32)
==4627==    by 0x407DF1: KafkaProducer::~KafkaProducer() (kafkaproducer.cpp:38)
==4627==    by 0x409DC0: KafkaProducerFactory::~KafkaProducerFactory() (kafkaproducerfactory.cpp:22)
==4627==    by 0x4045A8: main (test_kafkaproducerfactory.cpp:14)

kafkaproducer.cpp第56-67行(保留双空格):

 if(m_producer)           // line 56
     delete m_producer;
 if(m_topic)
     delete m_topic;

 if(m_tconf)
     delete m_tconf;
 if(m_conf)
     delete m_conf;       // line 67

欢迎任何帮助。

我已经发现下列代码导致了这个问题。如果我注释下面的部分(如果我没有设置事件回调函数)，问题就会消失。但是我不知道为什么它会导致这个问题。我用同样的方法设置了送货回调功能，没有出现任何问题。它是有线的

//defination
    class MyEventCb : public RdKafka::EventCb
    {
    public:
        void event_cb (RdKafka::Event &event)
        {
        }
    private:
    };
//set the callback function
    if( m_conf->set("event_cb", &m_event_cb, m_errstr) != RdKafka::Conf::CONF_OK)
    {
        DBG_PRINT( 1, "Kafka::Failed to set event callback : %sn", m_errstr.c_str() );
        return false;
    }
    // Class member
MyEventCb m_event_cb; // event callback

既然m_topic正在使用m_producer，我不认为你应该在m_topic之前删除m_producer…

相关文章：