mysql++中connection调用了2次析构函数

longshadian

隔壁mysql区没人理。。.
最近做的项目数据库连接用的mysql++,
代码如下
try {
      mysqlpp::ScopedConnection cp(*mPool,true);
} catch  {
....
}

有时程序会挂在ScopedConnection构造函数中，栈如下：
#1  0x00f38d2c in mysqlpp::Connection::~Connection() () from /usr/local/lib/libmysqlpp.so.3
#2  0x00f38dd2 in mysqlpp::Connection::~Connection() () from /usr/local/lib/libmysqlpp.so.3
#3  0x0806e44a in GameServerMysqlConnectPool::destroy (this=0xa9d4088, cp=0xaf17400) at ../game/GameServerMysqlConnectPool.h:75
#4  0x00f3bc1e in mysqlpp::ConnectionPool::remove(std::_List_iterator<mysqlpp::ConnectionPool::ConnectionInfo> const& ()
   from /usr/local/lib/libmysqlpp.so.3
#5  0x00f3bca9 in mysqlpp::ConnectionPool::remove_old_connections() () from /usr/local/lib/libmysqlpp.so.3
#6  0x00f3bf40 in mysqlpp::ConnectionPool::grab() () from /usr/local/lib/libmysqlpp.so.3
#7  0x0806e227 in GameServerMysqlConnectPool::grab (this=0xa9d408 at ../game/GameServerMysqlConnectPool.h:48
#8  0x00f3bda4 in mysqlpp::ConnectionPool::safe_grab() () from /usr/local/lib/libmysqlpp.so.3
#9  0x00f51e10 in mysqlpp::ScopedConnection::ScopedConnection(mysqlpp::ConnectionPool&, bool) ()
   from /usr/local/lib/libmysqlpp.so.3

#3  0x0806e44a in GameServerMysqlConnectPool::destroy (this=0xa9d4088, cp=0xaf17400) at ../game/GameServerMysqlConnectPool.h:75
    virtual void destroy(mysqlpp::Connection* cp)
    {
        delete cp;
    }

一次delete 执行了2次析构函数，两次析构函数的地址还是不同的。真是怪了。
程序很难重现，有没有同学遇到过这种情况。或者帮忙解释下大概什么情况下会出现2次析构。
代码是在多线程中调用的。可是我看mysql++源码中， mysqlpp::ConnectionPool::grab()是加锁的，真是郁闷了。