I seem to have an odd problem that every time i try to increment an integer that tracks the outgoing networking requests(the response requests will match that int so we can pair up response data). Well every time I try to increment the console will "block" and freeze at the incremntation? Is there any reason why it might do this? Its just a normal tracker_id += 1 code shouldn't be blocking and im usually am never noobish at these things.
Sometimes you may get the impression that the debugger is on one line while indeed the code is stopped at the istruction before or after.
If tracker_id is a simple variable (e.g. int, long) and not a class instance then there is no way that tracker_id += 1 is blocking. It's just impossible.
Note also that the compilers are becoming more and more liberal on how they translate source code to machine code, so be sure to compile with all optimizations disabled if you want to be able to track source code and variables correctly.
I had to classes in my main class, the first class is a simple networking class i created to easily call from an API (the Bitcoin JSON-RPC api so i could call just coin_server->getbalance()) the issue was that both classes were located in the main class and apparently the bitcoin class would be destroyed before it was set inside the game server class. There for it would explain why when i tried to call coin apis functions it would crash.
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There's an app that uses TLS callbacks to remap its memory using (NtCreateSection/NtUnmapViewOfSection/NtMapViewOfSection) using the SEC_NO_CHANGE flag.
Is there any way to hook NtCreateSection before the target app use it on its TLS callback?
You could use API Monitor to check if it is really that function call and if I understand you correctly you want to modify its invocation. API Monitor allows you to modify the parameters on the fly. If just "patching" the value when the application accesses the api is enough you could than use x64dbg to craft a persistent binary patch for your application. But this requires you to at least know or get familiar with basic x64/x86 assembler.
I have no idea what you're trying to achieve exactly but if you're trying to execute setup code before the main() function is called (to setup hooks), you could use the constructor on a static object. You would basically construct an object before your main program starts.
// In a .cpp file (do not put in a header as that would create multiple static objects!)
class StaticIntitializer {
StaticIntitializer(){
std::cout << "This will run before your main function...\n";
/* This is where you would setup all your hooks */
}
};
static StaticInitializer staticInitializer;
Beware though, as any object constructed this way might get constructed in any order depending on compilers, files order, etc. Also, some things might not be initialized yet and you might not be able to achieve what you want to setup.
That might be a good starting point, but as I said, I'm not sure exactly what you're trying to achieve here, so good luck and I hope it helps a little.
I would really appreciate your inputs on moving from a YieldTermStructure pointer to that of adding a spread as below::
boost::shared_ptr<YieldTermStructure> depoFutSwapTermStructure(new PiecewiseYieldCurve<Discount,
LogLinear>(settlementDate, depoFutSwapInstruments_New, termStructureDayCounter, 1.0e-15));
I tried adding a spread of 50 bps as below...
double OC_Spread(0.50 / 100);
Rate OCSQuote = OC_Spread;
boost::shared_ptr<Quote> OCS_Handler(new SimpleQuote(OCSQuote));
I then proceed to create a zerospreaded object as below:
ZeroSpreadedTermStructure Z_Spread(Handle<YieldTermStructure>(*depoFutSwapTermStructure), Handle<Quote>(OCS_Handler));
But now I am stuck as the code repeatedly breaks down if I go on ahead to do anything like
Z_Spread.zeroYieldImpl;
What is the issue with above code. I have tried several flavors of above approach and failed on all the fronts.
Also is there a native way of calling directly the discount function just like as I do now with the TermStructure object prior to adding the spread currently as below???
depoFutSwapTermStructure->discount(*it)
I'm afraid you got your interfaces a bit mixed up. The zeroYieldImpl method you're trying to call on your ZeroSpreadedTermStructure is protected, so you can't use it from your code (at least, that's how I'm guessing your code breaks, since you're not reporting the error you get).
The way you interact with the curve you created is through the public YieldTermStructure interface that it inherits; that includes the discount method that you want to call, as well as methods such as zeroRate or forwardRate.
Again, it's hard to say why your call to discount fails precisely, since you're not quoting the error and you're not saying what *it is in the call. From the initialization you do report, and from the call you wrote, I'm guessing that you might have instantiated a ZeroSpreadedTermStructure object but you're trying to use it with the -> syntax as if it were a pointer. If that's the case, calling Z_Spread.discount(*it) should work instead (assuming *it resolves to a number).
If that's not the problem, I'm afraid you'll have to add a few more details to your question.
Finally, for a more general treatment of term structures in QuantLib, you can read here and here.
I'm implementing a logger for an OpenGL application ( the only reason I'm mentioning it is that it runs in a loop ). I'd like to somehow log every method call or some group of method calls of some classes, every time they are called.
My initial approach was to place the required logger function call in all the methods ( which actually kind of works like comments :) ) but I got really tired of it really fast, so I started looking for a more effective way. I searched google for some time, but since I don't really know what I'm looking for, I ran out of ideas.
The best thing for my case would be some kind of magical method, that would be called every time I invoked any other class method, idealy with name and params string as a parameter for this method. ( kind of PHP - like magic method __call() - but that one works only if method is not defined ). I don't know what I am looking for, if something like that even exists, and if it does, what do we call it?
P.S.:
my logging works on macros, so no worries for performance there :)
#if DEV_LOG
#define log_init() logInit()
#define log_write(a,b) writeToLog(to_str(a), to_str(b))
#else
#define log_init()
#define log_write(a,b)
#endif
( And if there's a nicer way to do this, let me know, please :) )
Thank you!
1st I have to re-cite my co-answerer Filip here
C++ doesn't have this kind of "magical method", so you are stuck with explicitly stating a function call inside every member-function, if you'd like one to be made.
Such stuff is implemented as compiler specific features like the GCC profiling. There will be code generated to track for function calls, their parameters, and where these actually were called from and how often.
The general usage is to compile and link your code with special compiler flags that will generate this code. When your code is run, this information will be stored along specific kind of databases, that can be analyzed with a separate tool after running (as e.g. gprof for the GCC toolchain).
A similar tooling suite is used for retrieving code coverage of certain program runs (e.g. testsuites for your code): gcov A Test Coverage Program
C++ doesn't have this kind of "magical method", so you are stuck with explicitly stating a function call inside every member-function, if you'd like one to be made.
You could instead use a debugger to track the calls made, the program you've written shouldn't have to be responsible for questions such as "what code is called, when and with what?"; that's the exact question a profiler, or a debugger, was made to answer.
So I've got a pretty basic class that has a few methods and some class variables. Everythings working great up until I add a vector to the member variables in the header file:
std::vector <std::string> vectorofstuff;
If all I do is add this line then my program run perfectly but at the end, after all the output is there, I get a message about a seg fault.
My first guess is that I need to call the destructor on the vector, but that didn't seem to work. Plus my understanding is I don't need to call the destructor unless I use the word 'new'.
Any pushes in the right direction? Thanks bunches!
I guess the following either happened to you, or it was something similar involving unrealised dependencies/headers. Either way, I hope this answer might show up on Google and help some later, extremely confused programmer figure out why they're suddenly observing arbitrary crashes.
So, from experience, this can happen if you compile a new version of SomeObject.o but accidentally have another object file #include an old version of SomeObject.hpp. This leads to corruption, which'll be caused by the compiler referring to outdated member offsets, etc. Sometimes this mostly works and only produces segfaults when destructing objects - either related or seemingly distant ones - and other times the program segfaults right away or somewhere in-between; I've seen several permutations (regrettably!).
For anyone wondering why this can happen, maybe this is just a reflection of how little sleep I get while programming, but I've encountered this pattern in the context of Git submodules, e.g.:
MyRepo
/ GuiSubmodule
/ HelperSubmodule
/ / GuiSubmodule
If (A) you have a new commit in GuiSubmodule, which has not yet been pulled into HelperSubmodule's copy, (B) your makefile compiles MyRepo/uiSubmodule/SomeObject.o, and (C) another translation unit - either in a submodule or in the main repo via the perils of #include - links against an older version of SomeObject.hpp that has a different class layout... You're in for a fun time, and a lot of chasing red herrings until you finally realise the simple mistake.
Since I had cobbled together my build process from scratch, I might've just not been using Git/make properly - or strictly enough (forgetting to push/pull all submodules). Probably the latter! I see fewer odd bugs nowadays at least :)
You are probably corrupting the memory of the vectorofstuff member somewhere within your class. When the class destructor is called the destructor of the vector is called as well, which would try to point and/or delete to invalid memory.
I was fooling around with it and decided to, just to be sure, do an rm on everything and recompile. And guess what? That fixed it. I have no idea why, in the makefile I do this anyway, but whatever, I'm just glad I can move on and continue working on it. Thanks so much for all the help!
Apologies if I'm missing something really obvious, but I'm trying to understand how to write a custom front end and back end with Pantheios. (I'm using it from C++, not C.)
I can follow the purposes of the initialisation functions (I think) but I'm unsure about the others: pantheios_be_logEntry, pantheios_fe_getProcessIdentity and pantheios_fe_isSeverityLogged.
In particular, I'm confused about the relationship between a front end and a back end. How do I make them communicate with each other?
Not sure I understand exactly what you don't understand, but maybe that's part of the problem. ;-) So I'll try my best and you let me know whether it's near or not.
pantheios_fe_getProcessIdentity() is called once, when Pantheios is initializing. You need to return a string that identifies the process. (Actually, it identifies the link-unit; a term defined in Imperfect C++, written by Pantheios' creator, Matthew Wilson, which means the scope of link names, i.e. an executable program module or a dynamic library module.)
pantheios_fe_isSeverityLogged() is called whenever a log statement is executed in application code. It returns non-zero to indicate that the statement should be processed and sent to the output (via the back-end). If it returns zero, no processing occurs. FWIU, this is the main reason why Pantheios is so fast.
pantheios_be_logEntry() is called whenever a log statement is to be sent for output, when pantheios_fe_isSeverityLogged() has returned non-zero and the Pantheios core has processed the statement (forming all the arguments in your code into a single string). It sends the statement string to wherever it should go. For example, the be.fprintf back-end prints it to the console using fprint().
Once you grok these aspects, the second part of your question is where it gets interesting. When your front-end and back-end are initialized they get to create some context (e.g. a C++ object) that the Pantheios core holds for them, and gives them back each time it calls a front/back end API function. When you're customizing both, you can have them communicate via some shared context that they both know about, but which the Pantheios core does not (and should not) know about, beyond having an opaque handle (void*) to it.
HTH