嵌套的对象问题我有我使用作为体multifunction_node的功能对象:在施工时被创建与所述TBB ::流的功能对象::图表
class module
{
private:
bool valid;
QString description;
bool hasDetectionBranch;
tDataDescription bufData;
void* dllObject; //<-- This is a pointer to an object constructed with help of the external dll
qint64 TimeOut;
public:
module(const QString& _ExtLibName);
virtual ~module();
void operator() (pTransmitData _transmitData, multi_node::output_ports_type &op);
};
“dllObject”对象 '模块':
module::module(const QString& _ExtLibName) :
valid(true), hasDetectionBranch(false)
{
GetObjectDescription = (tGetObjectDescription)QLibrary::resolve(_ExtLibName, "GetObjectDescription");
CreateObject = (tCreateObject)QLibrary::resolve(_ExtLibName, "CreateObject");
DestroyObject = (tDestroyObject)QLibrary::resolve(_ExtLibName, "DestroyObject");
if (!CreateObject || !DestroyObject || !GetObjectDescription)
valid = false;
else
{
description = QString(GetObjectDescription());
dllObject = CreateObject();
}
}
而且这是在 'dllObject' 被破坏:
module::~module()
{
if (valid)
{
DestroyObject(dllObject);
}
}
我已经建立了一个小图:
void MainWindow::goBabyClicked(void)
{
module mod(QString("my.dll")); //<-- Here is OK and mod.dllObject is correct
if (!mod.isValid())
{
qDebug() << "mod is invalid!\n";
return;
}
first fir(input);
folder fol(QString("C:/out"), 10000);
graph g;
source_node<pTransmitData> src(g, fir, false);
multi_node mnode(g, tbb::flow::serial, mod); //<-- WTF? ~module() is executed!
function_node<pTransmitData> f(g, tbb::flow::serial, fol);
make_edge(src, mnode);
make_edge(mnode, f);
src.activate();
g.wait_for_all();
}
所以我有2个问题: 1)为什么〜模块()被执行以及如何防止这种情况? 2)如何正确保持嵌套对象的指针?
UPDATE增加了一些假的代码,以防止在第一时间摧毁dllObject像:
bool b = false;
module::~module()
{
if (valid && b)
{
DestroyObject(dllObject);
}
if (!b)
b = true;
valid = false;
}
现在的作品如预期,但看起来很难看:/
什么是'multi_node'?我不熟悉TBB流程图,但我试图寻找它。我找到的名字最接近的类是['multifunction_node'](https://www.threadingbuildingblocks.org/docs/help/index.htm)... –