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My first public solution

Pe6o Petkov · 2012-09-29T14:03:32

So this actually is my first solution I made . It is c++ new\delete memory leaks finder. It does an memory check at the end of the program and if some object created with new wasn't deleted it post a message with the object line and source file name. It use an a tree for collecting runtime memory actions. Here is the .cpp and .h file. I will be happy for any opinion and advice about this solution. MemoryHandler.cpp [source]#include <iostream> #include <windows.h> #include <stdio.h> #ifdef DEBUG struct MemoryAllocTree { char* File; unsigned int Line; MemoryAllocTree* next; void* MemoryPointer; } * _gpAllocTree(0) ; MemoryAllocTree** ppCurAllocTree(&_gpAllocTree); unsigned int _gCurLine; char* _gCurFile; #endif void* operator new(size_t size) { void* pMem(malloc(size ? size : 1)); if(!pMem) { #ifdef WIN32_MEM_LOG MessageBoxA(0, "No more memory to use. The app will exit now!", "Error!", MB_OK | MB_ICONERROR); #endif #ifndef WIN32_MEM_LOG std::cout << "No more memory to use. The app will exit now!" << "Error!" << std::endl; #endif exit(1); } #ifdef DEBUG (*ppCurAllocTree)=(MemoryAllocTree*)malloc(sizeof(MemoryAllocTree)); if(!(*ppCurAllocTree)) { #ifdef WIN32_MEM_LOG MessageBoxA(0, "No more memory to use for the debug version of MemoryHandler. Try compiling the app \ in release mode. It will exit now!", "Error!", MB_OK | MB_ICONERROR); #endif #ifndef WIN32_MEM_LOG std::cout << "No more memory to use for the debug version of MemoryHandler. Try compiling the app \ in release mode. It will exit now!" << "Error!" << std::endl; #endif exit(1); } (*ppCurAllocTree)->Line=_gCurLine; (*ppCurAllocTree)->File=_gCurFile; (*ppCurAllocTree)->MemoryPointer=pMem; (*ppCurAllocTree)->next=0; ppCurAllocTree=&(*ppCurAllocTree)->next; #endif return pMem; } void* operator new[](size_t size) { return operator new(size); } void operator delete[](void* pMem) { operator delete(pMem); } void operator delete(void* pMem) { if(!pMem) return; #ifdef DEBUG MemoryAllocTree* sourc(_gpAllocTree); while(sourc&&sourc->MemoryPointer!=pMem) sourc=sourc->next; if(!sourc) { #ifdef DEBUG #ifdef WIN32_MEM_LOG char str[80]; sprintf(str, "Invalid delete call at File: %s Line: %d", _gCurFile, _gCurLine); MessageBoxA(0, str, "Warning!", MB_OK | MB_ICONWARNING); #endif #ifndef WIN32_MEM_LOG std::cout << "Invalid delete call at File: " << _gCurFile << " Line: " << _gCurLine << " Warning!" << std::endl; #endif #endif return; } sourc->MemoryPointer=0; #endif free(pMem); return; } #ifdef DEBUG void EndOfProgramMemCheck() { MemoryAllocTree* pCurAllocTree(_gpAllocTree); while(pCurAllocTree) { if(pCurAllocTree->MemoryPointer) { #ifndef WIN32_MEM_LOG std::cout << "Object at line: " << pCurAllocTree->Line << " in file: " << pCurAllocTree->File << " wasn't deleted!" << std::endl; #endif #ifdef WIN32_MEM_LOG char str[80]; sprintf(str, "Object at line: %d in file: %s wasn't deleted!", pCurAllocTree->Line, pCurAllocTree->File); MessageBoxA(0, str, "Memory leaked!", MB_OK | MB_ICONWARNING); #endif } MemoryAllocTree* cach(pCurAllocTree); pCurAllocTree=pCurAllocTree->next; free(cach); } } #endif[/source] MemoryHandler.h [source]#pragma once /*Sasho 648 Memory Handle functions and memory leaks finder - define DEBUG to active it and add at the function EndOfProgramMemCheck() before exit your app. Define a WIN32_MEM_LOG to active an Win32 Messages. Type MEM_FUNC_CALL at the line begin where new\delete \[] function is called. Example: MEM_FUNC_CALL char* ptr = new char[50]; */ #ifdef DEBUG extern unsigned int _gCurLine; extern char* _gCurFile; #endif #ifdef DEBUG #define MEM_FUNC_CALL _gCurLine=__LINE__; _gCurFile=(char*)__FILE__; #endif #ifndef DEBUG #define MEM_FUNC_CALL #endif void* operator new(size_t size) ; void* operator new[](size_t size) ; void operator delete[](void* pMem) ; void operator delete(void* pMem) ; #ifdef DEBUG void EndOfProgramMemCheck() ; #endif [/source] You need to make compiling debug define (DEBUG) at the compiler options and for win32 message posting you need to define WIN32_MEM_LOG. Before each new\delete call you need to type MEM_FUNC_CALL. Here is a simple code using my solution: [source]class My { public: My() {std::cout<<"My::My()"<<std::endl;} ~My() {std::cout<<"My::~My()"<<std::endl;} } ; int main() { MEM_FUNC_CALL My* ptr=new My[23]; MEM_FUNC_CALL delete[] ptr; MEM_FUNC_CALL delete ptr; size_t* My_Size_T=new size_t; My_Size_T=(size_t*)0xbff7ffff; delete My_Size_T; #ifdef DEBUG EndOfProgramMemCheck(); #endif system("PAUSE"); return 0; }[/source] Here will print warning messages for invalid delete call (2) and a memory leak.

General and Gameplay Programming Programming

Started by sasho648 September 10, 2012 05:52 PM

24 comments, last by sasho648 11 years, 6 months ago

sasho648

Author

September 26, 2012 04:52 PM

@Brother Bob Thanks for the problem respond but I don't understand how do {} while() loop will help me.
@brx With your solution the user need to type () after the delete but the most delete calls are without them.

Here is my solution (which I'll correct in my last post):



#define DEL_OLD delete

#define delete if(PassDeleteParams(__FILE__, __LINE__)); else DEL_OLD

The problem now is more complex - the threads in the program can assign dynamicly created object on an global variables like this:



char* String;

unsigned long __stdcall Thread1 (void* lp)

{

	String=new char[50];

	#ifdef DEBUG

	EndThreadMemCheck();

	#endif

	return 0;

}

In this case it will give an error for an memory leak and when I delete it from the main thread it will give me message for an invalid delete call. Any suggestions to avoid this?

Brother Bob

10,350

September 26, 2012 05:47 PM

@Brother Bob Thanks for the problem respond but I don't understand how do {} while() loop will help me.

When it comes to calling macros, it doesn't force the use of a semicolon. It is never an error, nor is it never required, to call a macro with or without a semicolon; nor can you force any single convention upon the macro call itself. What the macro expands to for the compiler, however, may or may not require a semicolon.

The purpose of the do-while construct is to force the convention of a semicolon after the macro call just like you are forced to have a semicolon after a delete statement.

Now, I did overlook the else-statement in your macro so the comment to your particular macro was not correct. I believe it does expand correctly in any situation where the delete-syntax is correct. I would, however, suggest that if you take the advice with the do-while loop construct for any further macro that has any sort of local scope or control structure as the base of the macro.

Cornstalks

7,033

September 26, 2012 06:08 PM

@Brother Bob Thanks for the problem respond but I don't understand how do {} while() loop will help me.

Here is my solution (which I'll correct in my last post):

#define DEL_OLD delete #define delete if(PassDeleteParams(__FILE__, __LINE__)); else DEL_OLD

I suggest a normal [font=courier new,courier,monospace]do {} while (false)[/font], simply because it's more idiomatic. Particularly, some compilers may generate a warning about the [font=courier new,courier,monospace]if (true);[/font] body being empty. But it's up to you, I don't see a particular issue with that method.

Sorry I misled you on placement delete. It turns out that the syntax [font=courier new,courier,monospace]delete(params) ptr;[/font] is not supported in C++, which is why the macro was having issues with delete.

One more thing: you should use [font=courier new,courier,monospace]NULL[/font] (or [font=courier new,courier,monospace]nullptr[/font] if using C++11) for null pointers. 0 works, but [font=courier new,courier,monospace]NULL[/font]/[font=courier new,courier,monospace]nullptr[/font] are preferred in practice.

I don't know much about your threading issue as I've never used [font=courier new,courier,monospace]__thread[/font] before, sorry I'm not much help there.

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ATC

551

September 27, 2012 01:10 AM

HAHAHAHA!!! I was just watching that episode the other day lol! Sorry, but you literally made me LOL... XD

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Khatharr

8,814

September 27, 2012 02:22 AM

[quote name='sasho648' timestamp='1347299520' post='4978639'][source]MessageBoxA(0, str, "Memory leaked!", MB_OK | MB_ICONWARNING);[/source]

You make this call multiple times. Don't. Just use 'MessageBox'. The reason that there's a macro defining the name is for character width (I think).
[/quote]

The macro just resolves to either MessageBoxA() or MessageBoxW() depending on the compiler's set character width. If he's giving it a string literal it's best to call MessageBoxA().

void hurrrrrrrr() {__asm sub [ebp+4],5;}

There are ten kinds of people in this world: those who understand binary and those who don't.

sasho648

Author

September 29, 2012 02:03 PM

@Brother Bob I again don't understand how to include do{} while() loop in the delete define. Can you please snap a code example?

My thread issue now Is not simple - I need to use one static list structure because the global variables. So my program need to change:



void EndProgramMemCheck() ;



MemoryAllocList* & GetMemoryList()

{

static MemoryAllocList* pAllocList(0);

	return pAllocList;

}

MemoryAllocList** & GetMemoryCurrPtrList()

{

static MemoryAllocList** ppCurAllocList(0);

	return ppCurAllocList;

}



inline bool & bIsWorking()

{

	static bool Obj(0);

	return Obj;

}

inline unsigned long & UlThreads()

{

	static unsigned long Obj(0);

	return Obj;

}

These function will be needed for the new opeartor:



void* operator new(size_t size, const char* szFile, unsigned int nLineNo) _GLIBCXX_THROW (std::bad_alloc)

{

if(!bIsWorking()) bIsWorking()=true;

	else while(bIsWorking());

	void* pMem;

	while(true) {

		pMem=malloc(size ? size : 1);

		if(!pMem)

		{

			#ifdef WIN32_MEM_LOG

			MessageBoxA(0, "No more memory to use!", "Warning!", MB_OK | MB_ICONWARNING);

			#endif

			#ifndef WIN32_MEM_LOG

			std::cerr << "No more memory to use!" << "Warning!" << std::endl;

			#endif

			std::new_handler cach=std::set_new_handler(0);

			if(cach) (*cach)();

			else throw std::bad_alloc();

			std::set_new_handler(cach);

		}

		else

			break;

	}

	MemoryAllocList** & ppCurAllocList(GetMemoryCurrPtrList());

	if(!ppCurAllocList) //Thread first new call

	{

		ppCurAllocList=&GetMemoryList();

	}

UlThreads()++;

	NumThreadsInFunction=UlThreads();

	(*ppCurAllocList)=(MemoryAllocList*)malloc(sizeof(MemoryAllocList));

	if(!(*ppCurAllocList))

	{

		#ifdef WIN32_MEM_LOG

		MessageBoxA(0, "No more memory to use for the debug version of MemoryHandler. Try compiling the app \

					 in release mode. It will exit now!", "Error!", MB_OK | MB_ICONERROR);

		#endif

		#ifndef WIN32_MEM_LOG

		std::cerr << "No more memory to use for the debug version of MemoryHandler. Try compiling the app \

					 in release mode. It will exit now!" << "Error!" << std::endl;

		#endif

		exit(1);

	}

	(*ppCurAllocList)->Line=nLineNo;

	(*ppCurAllocList)->File=(char*)szFile;

	(*ppCurAllocList)->MemoryPointer=pMem;

	(*ppCurAllocList)->next=0;

	ppCurAllocList=&(*ppCurAllocList)->next;

	return pMem;

}

The first bold lines in this code are for threads which call the function with delay. The second bold lines are to resolve if there are multi-thread using the function at the same time. Here is the problem I can check and understand where and how many threads are using this code (at same time) but I don't know what to do next. Any suggestions?

My first public solution

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