I am trying to construct a child class object from a base class object. I have tried the below code.
class A
{
public:
A();
A(A&& objectName) = default;
virtual void setint(int i);
virtual void getint();
int var;
};
class B: public A
{
public:
virtual void getint();
B(A&& objectName);
int j= 20;
};
A::A()
{
}
void A::setint(int i)
{
var = i;
}
void A::getint()
{
qDebug()<<"From A Var"<<var;
}
void B::getint()
{
qDebug()<<"From B j"<<j;
qDebug()<<"From B Var"<<var;
}
B::B(A&& objectName): A(std::move(objectName))
{
}
And in my Main.cpp I am doing this
#include <memory>
int main(int argc, char *argv[])
{
A *obj = new A();
obj->setint(10);
obj->getint();
A *obj1 = new B(std::move(*obj));
obj->getint();
obj1->getint();
return 0;
}
The result I get is
From A Var 10
From A Var 10
From B j 20
From B Var 10
My question is why am I getting the value of Var after A *obj1 = new B(std::move(*obj)); this line. I thought the object pointed by obj must have been destructed.
Let me copy paste from this answer: https://stackoverflow.com/a/15663912/512225
std::move doesn't move from the object. It just returns an rvalue reference whose referand is the object, making it possible to move from the object.
Anyway your code is terrible. I hope you know. If you don't, ask for a review.
I am writing a code for Uniform Cost Search using a priority queue. I came across an error: Invalid Heap after using push function. I also tried to debug the code, but I didn't find the source of this error. Here's my code:
class Manager
{
private:
Parser *p;
Board* myBoard;
string algorithm;
string text;
unsigned int size;
stack<Brick> *myStack;
stack<Brick> *solution;
stack<Brick> *temp;
unsigned int trackCost;
set<pair<int,int>> mySet;
struct ComparatorGreaterThan {
bool operator() (const Brick lhs, const Brick rhs) {
return (lhs.getTrackCostUpToMe() > rhs.getTrackCostUpToMe());
}
};
public:
Manager();
~Manager();
void Start();
void parseText();
void presentBoard() const;
const void checkNeighbours( int i, int j,const int x,const int y,stack<Brick> *tempStack, const Brick father)const;
void returnNeighbours(const Brick node, stack<Brick>* tempStack,const Brick father);
bool DFS(const Brick node,const int depth,const Brick father)const;
void parseSolution();
void IDDFS();
void printSolution()const;
bool UCS();
};
and here's the UCS function:
bool Manager::UCS()
{
priority_queue<Brick,vector<Brick>,ComparatorGreaterThan> myQueue;
myQueue.push(myBoard->getRoot());
mySet.insert(myBoard->getRoot().getCoorddinates());//Set is used to know which elements,using the coordiantes, are in the PQ
while (!myQueue.empty())
{
Brick parent = myQueue.top();
myQueue.pop();
mySet.erase(parent.getCoorddinates());
if (parent.getSym() == 'G')//If goal is found
{
cout << parent.getTrackCostUpToMe();
return true;
}
stack<Brick> tempStack;//Keeps all the neighbours of current node.
returnNeighbours(parent, &tempStack,myBoard->getNode(parent.getFatherX(),parent.getFatherY()));//Finds all the neighbours of current node.
while (!tempStack.empty())
{
tempStack.top().setTrackCostUpToMe(parent.getTrackCostUpToMe());//Set the track cost of neighbour.
if (mySet.find(tempStack.top().getCoorddinates()) == mySet.end())//If we don't have neighrbour in the PQ
{
mySet.insert(tempStack.top().getCoorddinates());
myQueue.push(tempStack.top());
tempStack.pop();
}
else //We have the neighbour in the PQ
tempStack.pop();
}
}
return false;
}
For that part name[i] it shows error. I want to store names of computer in a string array
using namespace std;
class computer
{
protected:
string name[100];
string model[100];
int prize[100];
string ram[100];
int limit;
public:
computer()
{
limit=0;
}
void name()
{
cout<<"Enter your desire records limit = ";
cin>>limit;
for(int i=0;i<limit;i++)
{
cout<<"Name = ";
cin>>name[i];
}
}
};
Change name[i] into name (name[i] means to let user enter a char)
and change the name() to getname()
Code:
using namespace std;
class computer
{
protected:
string name[100];
string model[100];
int prize[100];
string ram[100];
int limit;
public:
computer()
{
limit=0;
}
void getname()
{
cout<<"Enter your desire records limit = ";
cin>>limit;
for(int i=0;i<limit;i++)
{
cout<<"Name = ";
cin>>name;
}
}
};
I am using third party API which I get streams from a callback function
int OnNewImage(BYTE *pData, int nLen)
When I run a simple C++ sample program from console
int continue = 1;
int OnNewImage(BYTE *pData, int nLen)
{
std::cout << "On new image is called" << std::endl;
return continue;
}
int main()
{
// This will block
int result = DownloadStream(/*params*/...,OnNewImage /*callbackfunction*/);
return 0;
}
I get no memory leaks.[ memory does not increase ]
But When I use this callback function in a directshow filter, it
produce memory leaks.[ memory increase regularly]
What may cause this? And how can I fix it? Any ideas?
UPDATE: My DirectShow Filter structure
What I do:
Basically
I get streams at "unsigned __stdcall DVRStreamThread(LPVOID
pvParam)" function which call back OnNewImage
Then i insert frames into my queue inside that callback[OnNewImage]
Finally At FillBuffer I consume frames from queue.
It is am h264 stream. I can able to set simple graph like this
MySourceFilter ---> H264 Decoder ---> Video Renderer
Here is my FilterSourceCode:
Well I have a simple queue which i insert incoming frames then consume:
SynchronisedQueue
template <typename T>
class SynchronisedQueue
{
public:
void Enqueue(const T& data)
{
boost::unique_lock<boost::mutex> lock(queueMutex);
dataQueue.push(data);
conditionVariable.notify_one();
}
T Dequeue()
{
boost::unique_lock<boost::mutex> lock(queueMutex);
while (dataQueue.size()==0)
{
conditionVariable.wait(lock);
}
T result=dataQueue.front(); dataQueue.pop();
return result;
}
int Size()
{
boost::unique_lock<boost::mutex> lock(queueMutex);
int size = dataQueue.size();
return size;
}
private:
std::queue<T> dataQueue;
boost::mutex queueMutex;
boost::condition_variable conditionVariable;
};
Then My Filter:
DvrSourceFilter [ header]
#define DVRSourceFilterName L"DVRDirectShowFilter"
#include <streams.h>
#include <process.h>
#include <MyDvrApi.h>
#include "SynchronisedQueue.h"
// {F89A85DA-F77C-4d44-893B-CCA43A49E7EF}
DEFINE_GUID(CLSID_DVRSourceFilter,
0xf89a85da, 0xf77c, 0x4d44, 0x89, 0x3b, 0xcc, 0xa4, 0x3a, 0x49, 0xe7, 0xef);
class DECLSPEC_UUID("34363248-0000-0010-8000-00AA00389B71") Subtype_H264;
class DVRSourceFilter;
using namespace std;
/*
* **********************
* DVRPin
* **********************
*/
class DVRPin : public CSourceStream
{
public:
DVRPin(HRESULT *phr, DVRSourceFilter *pFilter);
~DVRPin();
// Override the version that offers exactly one media type
HRESULT GetMediaType(CMediaType *pMediaType);
HRESULT DecideBufferSize(IMemAllocator *pAlloc, ALLOCATOR_PROPERTIES *pRequest);
HRESULT FillBuffer(IMediaSample *pSample);
static int OnNewImage(void *pUser, BYTE *pData, int nLen, int nCh, int tMts, int nType, void *returnHandle);
// Setters
void SetDvrIp(char* dvrIp);
void SetDvrPort( int dvrPort);
void SetDvrUserName( char * userName);
void SetDvrPassword(char* password);
void SetStartTime(int startTime);
void SetMilliSecond(int milliSecond);
void SetChannelNumber(int channelNumber);
void SetSize(int width, int height);
// Getters
char* GetDvrIp();
int GetDvrPort();
char* GetDvrUserName();
char* GetDvrPassword();
int GetStartTime();
int GetMilliSecond();
int GetChannelNumber();
int GetMode();
public:
char* dvrIp;
int dvrPort;
char* userName;
char* password;
int startTime;
int milliSecond;
int channelNumber;
BITMAPINFOHEADER m_bmpInfo;
BYTE* m_RGB24Buffer;
DWORD m_RGB24BufferSize;
bool streamCompleted;
int hDecHandle;
HANDLE m_hDVRStreamThreadHandle;
unsigned int m_dwThreadID;
SynchronisedQueue<std::vector<BYTE>> IncomingFramesQueue;
protected:
virtual HRESULT OnThreadCreate();
virtual HRESULT OnThreadDestroy();
virtual HRESULT DoBufferProcessingLoop();
};
/*
* **********************
* DVRSourceFilter
* *********************
*
*/
class DVRSourceFilter : public CSource
{
public:
DECLARE_IUNKNOWN;
static CUnknown * WINAPI CreateInstance(IUnknown *pUnk, HRESULT *phr);
STDMETHODIMP NonDelegatingQueryInterface(REFIID riid, void **ppv);
void SetDVRLiveParameters(char* dvrIP, int dvrPort, char* userName, char* password, int channelNumber, int width, int height);
private:
DVRSourceFilter(IUnknown *pUnk, HRESULT *phr);
~DVRSourceFilter();
private:
DVRPin *m_pPin;
};
DvrSourceFilter [implementation]
#include "DvrSourceFilter.h"
unsigned __stdcall DVRStreamThread(LPVOID pvParam)
{
DVRPin* streamReader = (DVRPin*)pvParam;
int channelBits = 1 << (streamReader->channelNumber - 1);
streamReader->m_RGB24BufferSize = streamReader->m_bmpInfo.biWidth * streamReader->m_bmpInfo.biHeight * 3;
streamReader->m_RGB24Buffer = (BYTE*)malloc(streamReader->m_RGB24BufferSize);
DownloadStream((LPCTSTR)streamReader->dvrIp,
streamReader->dvrPort , (LPCTSTR)streamReader->userName ,
(LPCTSTR)streamReader->password , channelBits, channelBits,
streamReader->startTime, streamReader->milliSecond,
streamReader->OnNewImage, (void*)streamReader);
streamReader->startTime = -2; // End Of Stream
return 0;
}
/*
* ******************
* DVRPin Class
* ******************
*/
DVRPin::DVRPin(HRESULT *phr, DVRSourceFilter *pFilter)
: CSourceStream(NAME("DVR Source Bitmap"), phr, pFilter, L"Out")
{
m_bmpInfo.biSize = sizeof(BITMAPINFOHEADER);
m_bmpInfo.biCompression = BI_RGB;
m_bmpInfo.biBitCount = 24;
m_bmpInfo.biPlanes = 1;
m_bmpInfo.biClrImportant = 0;
m_bmpInfo.biClrUsed = 0;
m_bmpInfo.biXPelsPerMeter = 0;
m_bmpInfo.biYPelsPerMeter = 0;
hDecHandle = 0;
m_RGB24Buffer = NULL;
m_RGB24BufferSize = 0;
streamCompleted = false;
startTime = -1; // Live Stream
*phr = S_OK;
}
DVRPin::~DVRPin()
{
}
int DVRPin::OnNewImage(void *pUser, BYTE *pData, int nLen, int nCh, int tMts, int nType, void *returnHandle)
{
DVRPin* reader = (DVRPin*)pUser;
if(reader->streamCompleted)
{
return false;
}
if(pData)
{
std::vector<BYTE> vecFrame(pData, pData + nLen/sizeof(pData[0]));
reader->IncomingFramesQueue.Enqueue(vecFrame);
}
return !reader->streamCompleted;
}
HRESULT DVRPin::OnThreadCreate()
{
m_hDVRStreamThreadHandle =
(HANDLE)_beginthreadex(NULL, 0, &DVRStreamThread, (void*)this, 0, &m_dwThreadID);
return S_OK;
}
HRESULT DVRPin::OnThreadDestroy() {
streamCompleted = true;
_endthreadex(0);
CloseHandle(m_hDVRStreamThreadHandle);
return S_OK;
}
HRESULT DVRPin::GetMediaType(CMediaType *pMediaType)
{
CAutoLock cAutoLock(m_pFilter->pStateLock());
CheckPointer(pMediaType, E_POINTER);
VIDEOINFOHEADER* pvi = (VIDEOINFOHEADER*)pMediaType->AllocFormatBuffer(sizeof(VIDEOINFOHEADER));
if (pvi == 0)
return(E_OUTOFMEMORY);
ZeroMemory(pvi, pMediaType->cbFormat);
pvi->bmiHeader = m_bmpInfo;
pvi->bmiHeader.biSizeImage = GetBitmapSize(&pvi->bmiHeader);
SetRectEmpty(&(pvi->rcSource));
SetRectEmpty(&(pvi->rcTarget));
pMediaType->SetType(&MEDIATYPE_Video);
pMediaType->SetFormatType(&FORMAT_VideoInfo);
pMediaType->SetTemporalCompression(FALSE);
// Work out the GUID for the subtype from the header info.
const GUID SubTypeGUID = __uuidof(Subtype_H264);//GetBitmapSubtype(&pvi->bmiHeader);
pMediaType->SetSubtype(&SubTypeGUID);
pMediaType->SetSampleSize(pvi->bmiHeader.biSizeImage);
return S_OK;
}
HRESULT DVRPin::DecideBufferSize(IMemAllocator *pAlloc, ALLOCATOR_PROPERTIES *pRequest)
{
HRESULT hr;
CAutoLock cAutoLock(m_pFilter->pStateLock());
CheckPointer(pAlloc, E_POINTER);
CheckPointer(pRequest, E_POINTER);
VIDEOINFOHEADER *pvi = (VIDEOINFOHEADER*) m_mt.Format();
if (pRequest->cBuffers == 0)
{
pRequest->cBuffers = 2;
}
pRequest->cbBuffer = pvi->bmiHeader.biSizeImage;
ALLOCATOR_PROPERTIES Actual;
hr = pAlloc->SetProperties(pRequest, &Actual);
if (FAILED(hr))
{
return hr;
}
if (Actual.cbBuffer < pRequest->cbBuffer)
{
return E_FAIL;
}
return S_OK;
}
HRESULT DVRPin::FillBuffer(IMediaSample *pSample)
{
if(!streamCompleted)
{
CAutoLock cAutoLock(m_pLock);
HRESULT hr;
BYTE* pData = NULL;
hr = pSample->GetPointer(&pData);
if(FAILED(hr))
{
pSample->Release();
return hr;
}
if(IncomingFramesQueue.Size() <= 0) {
return S_OK;
}
vector<BYTE> data = IncomingFramesQueue.Dequeue();
int dataSize = (int)data.size();
if(dataSize <= 0 || dataSize > 1000000)
{
return S_OK;
}
memcpy(pData, &data[0], dataSize);
hr = pSample->SetActualDataLength(dataSize);
if(FAILED(hr))
{
pSample->Release();
return hr;
}
hr = pSample->SetSyncPoint(TRUE);
if(FAILED(hr))
{
pSample->Release();
return hr;
}
pSample->Release();
}
return S_OK;
}
HRESULT DVRPin::DoBufferProcessingLoop() {
Command com;
REFERENCE_TIME rtNow = 0L;
REFERENCE_TIME rtAdvise = 0L;
OnThreadStartPlay();
do {
while (!streamCompleted && !CheckRequest(&com)) {
IncomingFramesQueue.WaitUntilHaveElements();
IMediaSample *pSample;
HRESULT hr = GetDeliveryBuffer(&pSample,NULL,NULL,FALSE);
if (FAILED(hr)) {
continue; // go round again. Perhaps the error will go away
// or the allocator is decommited & we will be asked to
// exit soon.
}
hr = FillBuffer(pSample);
if (hr == S_OK) {
Deliver(pSample);
} else if (hr == S_FALSE) {
pSample->Release();
DeliverEndOfStream();
return S_FALSE;
} else {
// Log Error
}
pSample->Release();
}
if (com == CMD_RUN || com == CMD_PAUSE)
com = GetRequest(); // throw command away
else if (com != CMD_STOP)
{
// Log Error
}
} while (!streamCompleted && com != CMD_STOP);
return S_OK;
}
void DVRPin::SetDvrIp( char* dvrIp )
{
this->dvrIp = dvrIp;
}
void DVRPin::SetDvrPort( int dvrPort )
{
this->dvrPort = dvrPort;
}
void DVRPin::SetDvrUserName( char * userName )
{
this->userName = userName;
}
void DVRPin::SetDvrPassword( char* password )
{
this->password = password;
}
void DVRPin::SetStartTime( int startTime )
{
this->startTime = startTime;
}
void DVRPin::SetMilliSecond( int milliSecond )
{
this->milliSecond = milliSecond;
}
void DVRPin::SetSize(int width, int height) {
m_bmpInfo.biWidth = width;
m_bmpInfo.biHeight = height;
m_bmpInfo.biSizeImage = GetBitmapSize(&m_bmpInfo);
}
char* DVRPin::GetDvrIp()
{
return dvrIp;
}
int DVRPin::GetDvrPort()
{
return dvrPort;
}
char* DVRPin::GetDvrUserName()
{
return userName;
}
char* DVRPin::GetDvrPassword()
{
return password;
}
int DVRPin::GetStartTime()
{
return startTime;
}
int DVRPin::GetMilliSecond()
{
return milliSecond;
}
void DVRPin::SetChannelNumber( int channelNumber )
{
this->channelNumber = channelNumber;
}
int DVRPin::GetChannelNumber()
{
return channelNumber;
}
/*
* ****************************
* DVRSourceFilter Class
* ***************************
*/
DVRSourceFilter::DVRSourceFilter(IUnknown *pUnk, HRESULT *phr)
: CSource(NAME("DVRSourceBitmap"), pUnk, CLSID_DVRSourceFilter)
{
// The pin magically adds itself to our pin array.
m_pPin = new DVRPin(phr, this);
// Just for test at graph studio
SetDVRLiveParameters("192.168.3.151", 7000, "admin", "000000", 3, 352, 288);
if (phr)
{
if (m_pPin == NULL)
*phr = E_OUTOFMEMORY;
else
*phr = S_OK;
}
}
DVRSourceFilter::~DVRSourceFilter()
{
delete m_pPin;
}
CUnknown * WINAPI DVRSourceFilter::CreateInstance(IUnknown *pUnk, HRESULT *phr)
{
DVRSourceFilter *pNewFilter = new DVRSourceFilter(pUnk, phr);
if (phr)
{
if (pNewFilter == NULL)
*phr = E_OUTOFMEMORY;
else
*phr = S_OK;
}
return pNewFilter;
}
STDMETHODIMP DVRSourceFilter::NonDelegatingQueryInterface( REFIID riid, void **ppv )
{
return CSource::NonDelegatingQueryInterface(riid, ppv);
}
void DVRSourceFilter::SetDVRLiveParameters( char* dvrIP, int dvrPort, char* userName, char* password, int channelNumber, int width, int height )
{
m_pPin->SetDvrIp(dvrIP);
m_pPin->SetDvrPort(dvrPort);
m_pPin->SetDvrUserName(userName);
m_pPin->SetDvrPassword(password);
m_pPin->SetChannelNumber(channelNumber);
m_pPin->SetStartTime(-1);// Live Stream
m_pPin->SetMilliSecond(0);
m_pPin->SetSize(width, height);
}
...
To make directshow Filter simple [ to understand memory leak source], just implement OnNewImage function and FillBufferFunction as "dummy", but still has memory leak:
int DVRPin::OnNewImage(void *pUser, BYTE *pData, int nLen, int nCh, int tMts, int nType, void *returnHandle)
{
return 1; // for not to end call back
}
HRESULT DVRPin::FillBuffer(IMediaSample *pSample)
{
pSample->Release();
return S_OK;
}
In DVRStreamThread, you have:
streamReader->m_RGB24Buffer = (BYTE*)malloc(streamReader->m_RGB24BufferSize);
But I don't see a matching call to free() anywhere. When your DVRPin object is deleted, you will have to explicitly free the data pointed to by its m_RGB24Buffer member.
First thing I see, is that your destructors are not virtual. This might be a cause of leaks when release is not taking place when inheritance is used. See related article about the necessity of virtual destructors.
How can I convert a C++/CLI int %tmp to native C++ int &tmp?
void test(int %tmp)
{
// here I need int &tmp2 for another pure C++ function call
}
Neither of the existing answers properly handle in/out parameters, let alone any advanced use cases.
This should work for all cases where other_func does not keep the reference after it returns:
void test(int %tmp)
{
pin_ptr<int> pinned_tmp = &tmp;
other_func(*pinned_tmp);
}
Just tried this, works fine:
//in the C++ dll
void testFunc( int& n )
{
n = 5;
}
//in the CLI app
[DllImport( "my.dll", EntryPoint = "?exported_name_here",
CallingConvention = CallingConvention::StdCall )]
void TestFunc( int& );
void test( int% tmp )
{
int n;
TestFunc( n );
tmp = n;
}
void your_function(int *);
void your_function2(int &);
void test(int %tmp)
{
int tmp2;
your_function(&tmp2);
your_function2(tmp2);
tmp=tmp2;
}