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Your basic problem appears to be to understand how Header Files, cpp Files, the Compiler and the Linker work.
First the Compiler. The Compiler builds an Object File. This is a Binary representation of a cpp File. It containd the CPP Code you wrote, converted to machine code as well as a whole raft of information needed later. The Compiler contains a thing, called a Pre-Processor. It prepares your CPP file before actual compilation. Conceptually it produces a New Source File. It copies your file Line by Line. but if it finds a statement like #include "MyBeautifulHdr.h", it does not copy the include statement, but, instead writes the entire contents of "MyBeautifulHdr.h" at the location of the '#include' statement. When it encounters a #define FOO 1 statement, it undertakes to replace henceforth every future occurrence of 'FOO' with 1. It goes on like that at infinitum, and the final file offered to the compiler has all '#includes, #defines, #if's etc resolved.
At that stage the compiler does not know ( and does not care) from what file what item came from, (except for error reporting). It just builds the Object File, (if it Can)
if it cannot, you get an error.
Each of the Object Files generated roughly correspond to the code you wrote in a cpp file.
An extern declaration is a promise to the compiler that somewhere in an other file or library, an item of that specification exists.
The Linker tries to build an executable out of all those object files. In doing so, it may also include Object files written by others, e.g. those written by Microsoft, which came with your compiler package. To make that process more efficient, multiple obj files can be gathered together into a library (.lib) file
If the linker cannot find a named item, or, finds more than one, the linker will fail building the executable.
Getting a Full understanding of how your tools work will answer your queery.
regards,
Bram van Kampen
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I have this benchmark program that started off as a console program and I am now well into making work with a window instead. It's all Win32 for the most part with a smattering of C++ STL for some containers.
I launch the background via a keyboard command ctrl-r
case (0x52):
if(GetKeyState(VK_LCONTROL) || GetKeyState(VK_RCONTROL)) {
_beginthread(showtime, NULL, NULL);
}
break;
So what am I doing wrong, the background thread runs for while but crashes, used to work fine.
http://www.contract-developer.tk
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What is it the background thread doing? Do you get an exception or any other information when it crashes?
The best things in life are not things.
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void showtime(void *dummy) {
computing = true;
output.clear();
output = _TEXT("Fibonacci 3.0.0 for Windows");
output += ToString("/n/l/n/l");
output += _TEXT("(c) 2010-1 583727 BC Ltd, All Rights Reserved.");
output += _TEXT("/n/l");
output += _TEXT("Free for peronsal use only");
output += _TEXT("/n/l/n/l");
output += _TEXT("Commercial and government use requires a license");
output += _TEXT("/n/l/n/l");
output += _TEXT("To acheieve consistant results, run this program in the clean boot mode");
output += _TEXT("/n/l");
output += _TEXT("Click on start, in the seach box enter 'msconfig' and choose the startup tab, disable everyting and reboot");
output += _TEXT("/n/l/n/l");
output += _TEXT("RAM Performance ");
output += ToString(benchmark(fib2));
output += _TEXT(" seconds");
output += _TEXT("/n/l");
output += _TEXT("Scalar Performance ");
output += ToString(benchmark(fib3));
output += _TEXT(" seconds");
output += _TEXT("/n/l");
output += _TEXT("CPU Large Multiplication Performance ");
output += ToString(benchmark(fib4));
output += _TEXT(" seconds");
output += _TEXT("/n/l");
v.resize(0); t.resize(0);
output += _TEXT("Recursive Factorial Performance ");
output += ToString(benchmark(RunFact));
output += _TEXT(" seconds");
output += _TEXT("/n/l");
output += _TEXT("Bubble Sort Performance ");
output += ToString(benchmark(RunBubbleSort));
output += _TEXT(" seconds");
output += _TEXT("/n/l");
output += _TEXT("Insertion Sort Performance ");
output += ToString(benchmark(RunInsertionSort));
output += _TEXT(" seconds");
output += _TEXT("/n/l");
output += _TEXT("Shell Sort Performance ");
output += ToString(benchmark(RunShellSort));
output += _TEXT(" seconds");
output += _TEXT("/n/l");
output += _TEXT("Quick Sort Performance ");
output += ToString(benchmark(RunQuickSort));
output += _TEXT(" seconds");
output += _TEXT("/n/l");
output += _TEXT("Merge Sort Performance ");
output += ToString(benchmark(RunMergeSort));
output += _TEXT(" seconds");
output += _TEXT("/n/l");
output += _TEXT("Heap Sort Performance ");
output += ToString(benchmark(RunHeapSort));
output += _TEXT(" seconds");
output += _TEXT("/n/l");
output += _TEXT("Parallel Bitwise Sieve of Eratosthenes Performance ");
output += ToString(benchmark(sieve));
output += _TEXT(" seconds");
output += _TEXT("/n/l");
output += _TEXT("Parallel Goldbach Conjecture Performance Performance ");
output += ToString(benchmark(goldbach));
output += _TEXT(" seconds");
output += _TEXT("/n/l");
output += _TEXT("Parallel Collatz Conjecture Performance ");
output += ToString(benchmark(RunCollatz));
output += _TEXT(" seconds");
output += _TEXT("/n/l");
output += _TEXT("Parallel vector<float> normalization ");
output += ToString(benchmark(vtestfloat));
output += _TEXT(" seconds");
output += _TEXT("/n/l");
output += _TEXT("Parallel vector<double> normalization ");
output += ToString(benchmark(vtestdouble));
output += _TEXT(" seconds");
output += _TEXT("/n/l");
output += _TEXT("Parallel vector<std::complex> normalization ");
output += ToString(benchmark(vtestcomplex));
output += _TEXT(" seconds");
output += _TEXT("/n/l");
output += _TEXT("Parallel matrix<float> multiplication ");
output += ToString(benchmark(mtest1));
output += _TEXT(" seconds");
output += _TEXT("/n/l");
output += _TEXT("Parallel matrix<double> multiplication ");
output += ToString(benchmark(mtest2));
output += _TEXT(" seconds");
output += _TEXT("/n/l");
output += _TEXT("Parallel matrix<std::complex> multiplication ");
output += ToString(benchmark(mtest3));
output += _TEXT(" seconds");
output += _TEXT("/n/l/n/l");
computing = false;
MessageBox(NULL, L"Completed", L"Fibonacci", MB_OK);
}
http://www.contract-developer.tk
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What is output and why are you putting so much text into it for no apparent reason?
The best things in life are not things.
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typedef std::basic_string<wchar_t> tstring;
tstring output;
The output will eventually be placed on the clipboard as a text
http://www.contract-developer.tk
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You have still given no information as to where this crashes, and what exceptions or other diagnostic information you see. We cannot guess what happens on your system; have you tried running it through the debugger?
The best things in life are not things.
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I am going to use MessageBox all over the module and see how far it gets.
One question, do I need to use the exitthread anywhere?
http://www.contract-developer.tk
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VeganFanatic wrote: do I need to use the exitthread anywhere?
Impossible to say; it depends what your program is actually trying to do. Are you sure you need multiple threads?
The best things in life are not things.
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Putting that module into a thread was to make the program able to quit at any time.
This was to make sure the message handler is able to get messages.
http://www.contract-developer.tk
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From looking at the code you posted, its probably because another thread accesses or destroys output while the thread is still using it. The way you're using the string is also very bad practice since you're forcing it to reallocate memory constantly for the string and this is very inefficient. Why not get all the information you need once, then allocate/format your string? This would allow the thread to run way faster and more efficiently.
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When you have this run on one thread, does it complete properly?
I would do 3 things to trouble shoot and improve the code:
1) Add another command to your console entry, that allows you to start the "showtime" function, and run it one the same thread. Verify that it functions properly.
2) Enable Exceptions. I assume you are using Visual Studio of some sort, if not you will have to figure out how to do this for your debugger. In Visual Studio you can do this at the Debug | Exceptions Menu. Enable: C++ Exceptions, Native Run-Time Checks and Win32 Exceptions.
When you run your application in the debugger and it crashes, you will be right at the point in code the exception is thrown. Then you can look at the stack and all of the other helpful information.
3) Break up all of the work done in "showtime" into a smaller pieces. Probably a common function that prints out the basic text and runs the test you initiate. Then in "showtime" you would make multiple calls to your smaller function. This will help make your code more manageable.
From looking at your code, my guess is that one of the test routines is returning a NULL or some value that the string functions dont like, or is failing internally.
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Hello all,
Could anyone please give me a efficient method and suggestions for the following.
I have many classes already in my VC++ project, which were build on MFC. Meaning the data types were MFC based. like CByteArray, CString etc etc. Now I need to avoid the uses of MFC data types , and introduce STL data types.
could you please give me an efficient and less time consuming method to migrate the same. For eg: shal I use my own classes to mimic MFC classes like CString. or correct each uses/mehtod of MFC classes wherver there is, and change with STL based methods.... I am a bit confuse. please suggest me
thanks in advance
Hrishi
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Hi Hrishi,
hrishi321 wrote: I have many classes already in my VC++ project, which were build on MFC. Meaning
the data types were MFC based. like CByteArray, CString etc etc. Now I need to
avoid the uses of MFC data types , and introduce STL data types.
As MFC internally uses its own collection and string classes, you will increase your code footprint, and keep dependancy on all MFC classes and data types.
Anyhow you can use CStdString[^] as drop-in replacement for CString, and you should write your own CStdByteArray etc.. based on STL collections and exposing the same interface as the matching MFC collections. It could be an interesting CodeProject article
Good luck!
AR
When the wise (person) points at the moon the fool looks at the finger (Chinese proverb)
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Thank you so much for your kind suggestion.
I already started my implementation. Thought I am sure, I will have small doubts on my path.
As a starter, I am trying to implement the CBytearray, Could you please tell me, whether do I need to implement FreeExtra() method of MFC CBytearray, in my stl:: vector? . Is there any methods to mimic this? Or actually STL tales care of it own?
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Hi,
If your compiler supports C++2011 (VC2010 or gcc 4.5) std::vector::shrink_to_fit() is the functional equivalent to CByteArray::FreeExtra().If you are on C++2003 use v.reserve(v.size()) to achieve the same goal.
cheers,
AR
When the wise (person) points at the moon the fool looks at the finger (Chinese proverb)
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There's A LOT that goes into writing a framework, so you certainly don't want to write your own replacement classes. Depending on how much of the project is MFC based, you may have issues trying to replace with only STL calls. Some concepts don't exactly translate well, for example, what is a CDialog (the base for creating dialogs in MFC)? Well, its a bunch of WinAPI calls that create windows, configure properties, and act as a container for code within the dialog. How would you replicate that with STL alone? You can, but its a lot of work, STL is not exactly a framework that comes equipped as an MFC replacement (or replacement for any type of framework for that matter).
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thanks for your suggestion. After doing a small research and checking the amount of use of the MFC types, I have decided to implement the MFC types, whichever are in my project, and of-course not all methods but eh necessary ones.
I will have many doubts during this course of time, Hope to keep getting advices from you
thanks
hrishi
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Why do you want to do that! Horses for Courses.
Do you also want to migrate from Exel to Word?
Regards,
Bram van Kampen
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I have this code below that updates a dbf file now this code before also updates a cdx file but I changed something in the values I added now the cdx file is not inline with the dbf.
I have tried to "reindex" and "SET INDEX TO" however everytime I do an insert in the dbf table the modified date of the cdx file stays the same as the old one.
Should the cdx be updated everytime there is something new inserted?
DIAGNOSTICS_CHECKPOINT;
LOG(L"AutoLoad File Connection String");
LOG(this->_connectionstring.c_str());
cnn->CursorLocation = adUseClient;
try { hr = cnn->Open(this->_connectionstring.c_str(), L"", L"", 0); }
catch (_com_error& e)
{ wss.str(L"");
wss << L"Opening the AutoloadFile connection from '"
<< _connectionstring.c_str()
<< L"' has failed (COM Error: " << e.ErrorMessage()
<< L", " << hr << L")."
<< std::endl;
LOG(wss.str().c_str());
throw;
}
DIAGNOSTICS_CHECKPOINT;
wss.str(L"");
wss << L"INSERT INTO "
<< this->_tablename
<< L" VALUES ('"
<< trans_id << L"','"
<< params << L"','"
<< status << L"',"
<< rec_no << L")"
;
DIAGNOSTICS_CHECKPOINT;
std::wstring sql(wss.str().c_str());
LOG(L"Executing INSERT into the autoload file");
LOG(sql.c_str());
try
{ rs->Open(sql.c_str(), cnn.GetInterfacePtr(),
adOpenForwardOnly, adLockReadOnly, adCmdText);
}
catch (_com_error& e)
{ wss.str(L"");
wss << L"Executing SQL statement:\n"
<< sql.c_str()
<< L"'\n...has failed (COM Error: "
<< e.Error() << L", '"
<< e.ErrorMessage()
<< L"')."
<< std::endl;
LOG(wss.str().c_str());
throw;
}
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Hi All
I am working on a localization project.
I am trying to localize the Tool tips of the Tool bar buttons that are coming in English.
Tool tips are specified in the resource as direct strings in the prompt field of the properties.
Can you please advice me on how to refer the strings from String Table instead.
Any help is appreciated.
Thanks in advance.
Selva
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Insert new 'String Table' resource. Add your strings to it. Use LoadString function to get the strings.
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Hi Selva,
SelvaKr wrote: Tool tips are specified in the resource as direct strings in the prompt field of
the properties.
The VC resource editor intends to help you to create toolbar tooltips, they are actually in the resource stringtable.
For instance in your .rc file you have:
STRINGTABLE
BEGIN
ID_FILE_NEW "Create a new document\nNew"A toolbar button's tooltip is the part of the string resource with same ID following '\n'.
As the part preceding '\n' is the status bar text when a menu entry with same ID is hovered you can localize the strings matching your menus and toolbars in one step.
cheers,
AR
When the wise (person) points at the moon the fool looks at the finger (Chinese proverb)
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So in porting my VS6 MFC app to VS2010 I'm plagued with hundreds of C4407 warnings. And Google is giving me no joy on how to fix it.
(...cast between different pointer to member representations, compiler may generate incorrect code...
...Compiling with the /vmm might help...)
So the question is, can I ignore the warning? How likely is this "incorrect code" and what might be the result? (I end up in the wrong base class?)
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Kyudos wrote: So the question is, can I ignore the warning?
Well, possibly, but it depends on what you are doing. The warning comes from the use of a cast that may lead to the compiler making a wrong assumption about what you are trying to do. It would be better if you asked yourself why you have so many cast operators and what are they there for? Perhaps if you posted some of the code where the error occurs it may help someone to offer a better suggestion.
The best things in life are not things.
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