Search Results

Search found 341 results on 14 pages for 'destructor'.

Page 14/14 | < Previous Page | 10 11 12 13 14 

  • How should I delete a child object from within a parent's slot? Possibly boost::asio specific.

    - by kaliatech
    I have written a network server class that maintains a std::set of network clients. The network clients emit a signal to the network server on disconnect (via boost::bind). When a network client disconnects, the client instance needs to be removed from the Set and eventually deleted. I would think this is a common pattern, but I am having problems that might, or might not, be specific to ASIO. I've tried to trim down to just the relevant code: /** NetworkServer.hpp **/ class NetworkServices : private boost::noncopyable { public: NetworkServices(void); ~NetworkServices(void); private: void run(); void onNetworkClientEvent(NetworkClientEvent&); private: std::set<boost::shared_ptr<const NetworkClient>> clients; }; /** NetworkClient.cpp **/ void NetworkServices::run() { running = true; boost::asio::io_service::work work(io_service); //keeps service running even if no operations // This creates just one thread for the boost::asio async network services boost::thread iot(boost::bind(&NetworkServices::run_io_service, this)); while (running) { boost::system::error_code err; try { tcp::socket* socket = new tcp::socket(io_service); acceptor->accept(*socket, err); if (!err) { NetworkClient* networkClient = new NetworkClient(io_service, boost::shared_ptr<tcp::socket>(socket)); networkClient->networkClientEventSignal.connect(boost::bind(&NetworkServices::onNetworkClientEvent, this, _1)); clients.insert(boost::shared_ptr<NetworkClient>(networkClient)); networkClient->init(); //kicks off 1st asynch_read call } } // etc... } } void NetworkServices::onNetworkClientEvent(NetworkClientEvent& evt) { switch(evt.getType()) { case NetworkClientEvent::CLIENT_ERROR : { boost::shared_ptr<const NetworkClient> clientPtr = evt.getClient().getSharedPtr(); // ------ THIS IS THE MAGIC LINE ----- // If I keep this, the io_service hangs. If I comment it out, // everything works fine (but I never delete the disconnected NetworkClient). // If actually deleted the client here I might expect problems because it is the caller // of this method via boost::signal and bind. However, The clientPtr is a shared ptr, and a // reference is being kept in the client itself while signaling, so // I would the object is not going to be deleted from the heap here. That seems to be the case. // Never-the-less, this line makes all the difference, most likely because it controls whether or not the NetworkClient ever gets deleted. clients.erase(clientPtr); //I should probably put this socket clean-up in NetworkClient destructor. Regardless by doing this, // I would expect the ASIO socket stuff to be adequately cleaned-up after this. tcp::socket& socket = clientPtr->getSocket(); try { socket.shutdown(boost::asio::socket_base::shutdown_both); socket.close(); } catch(...) { CommServerContext::error("Error while shutting down and closing socket."); } break; } default : { break; } } } /** NetworkClient.hpp **/ class NetworkClient : public boost::enable_shared_from_this<NetworkClient>, Client { NetworkClient(boost::asio::io_service& io_service, boost::shared_ptr<tcp::socket> socket); virtual ~NetworkClient(void); inline boost::shared_ptr<const NetworkClient> getSharedPtr() const { return shared_from_this(); }; boost::signal <void (NetworkClientEvent&)> networkClientEventSignal; void onAsyncReadHeader(const boost::system::error_code& error, size_t bytes_transferred); }; /** NetworkClient.cpp - onAsyncReadHeader method called from io_service.run() thread as result of an async_read operation. Error condition usually result of an unexpected client disconnect.**/ void NetworkClient::onAsyncReadHeader( const boost::system::error_code& error, size_t bytes_transferred) { if (error) { //Make sure this instance doesn't get deleted from parent/slot deferencing //Alternatively, somehow schedule for future delete? boost::shared_ptr<const NetworkClient> clientPtr = getSharedPtr(); //Signal to service that this client is disconnecting NetworkClientEvent evt(*this, NetworkClientEvent::CLIENT_ERROR); networkClientEventSignal(evt); networkClientEventSignal.disconnect_all_slots(); return; } I believe it's not safe to delete the client from within the slot handler because the function return would be ... undefined? (Interestingly, it doesn't seem to blow up on me though.) So I've used boost:shared_ptr along with shared_from_this to make sure the client doesn't get deleted until all slots have been signaled. It doesn't seem to really matter though. I believe this question is not specific to ASIO, but the problem manifests in a peculiar way when using ASIO. I have one thread executing io_service.run(). All ASIO read/write operations are performed asynchronously. Everything works fine with multiple clients connecting/disconnecting UNLESS I delete my client object from the Set per the code above. If I delete my client object, the io_service seemingly deadlocks internally and no further asynchronous operations are performed unless I start another thread. I have try/catches around the io_service.run() call and have not been able to detect any errors. Questions: Are there best practices for deleting child objects, that are also signal emitters, from within parent slots? Any ideas as to why the io_service is hanging when I delete my network client object?

    Read the article

  • Pass a Delphi class to a C++ function/method that expects a class with __thiscall methods.

    - by Alan G.
    I have some MSVC++ compiled DLL's for which I have created COM-like (lite) interfaces (abstract Delphi classes). Some of those classes have methods that need pointers to objects. These C++ methods are declared with the __thiscall calling convention (which I cannot change), which is just like __stdcall, except a this pointer is passed on the ECX register. I create the class instance in Delphi, then pass it on to the C++ method. I can set breakpoints in Delphi and see it hitting the exposed __stdcall methods in my Delphi class, but soon I get a STATUS_STACK_BUFFER_OVERRUN and the app has to exit. Is it possible to emulate/deal with __thiscall on the Delphi side of things? If I pass an object instantiated by the C++ system then all is good, and that object's methods are called (as would be expected), but this is useless - I need to pass Delphi objects. Edit 2010-04-19 18:12 This is what happens in more detail: The first method called (setLabel) exits with no error (though its a stub method). The second method called (init), enters then dies when it attempts to read the vol parameter. C++ Side #define SHAPES_EXPORT __declspec(dllexport) // just to show the value class SHAPES_EXPORT CBox { public: virtual ~CBox() {} virtual void init(double volume) = 0; virtual void grow(double amount) = 0; virtual void shrink(double amount) = 0; virtual void setID(int ID = 0) = 0; virtual void setLabel(const char* text) = 0; }; Delphi Side IBox = class public procedure destroyBox; virtual; stdcall; abstract; procedure init(vol: Double); virtual; stdcall; abstract; procedure grow(amount: Double); virtual; stdcall; abstract; procedure shrink(amount: Double); virtual; stdcall; abstract; procedure setID(val: Integer); virtual; stdcall; abstract; procedure setLabel(text: PChar); virtual; stdcall; abstract; end; TMyBox = class(IBox) protected FVolume: Double; FID: Integer; FLabel: String; // public constructor Create; destructor Destroy; override; // BEGIN Virtual Method implementation procedure destroyBox; override; stdcall; // empty - Dont need/want C++ to manage my Delphi objects, just call their methods procedure init(vol: Double); override; stdcall; // FVolume := vol; procedure grow(amount: Double); override; stdcall; // Inc(FVolume, amount); procedure shrink(amount: Double); override; stdcall; // Dec(FVolume, amount); procedure setID(val: Integer); override; stdcall; // FID := val; procedure setLabel(text: PChar); override; stdcall; // Stub method; empty. // END Virtual Method implementation property Volume: Double read FVolume; property ID: Integer read FID; property Label: String read FLabel; end; I would have half expected using stdcall alone to work, but something is messing up, not sure what, perhaps something to do with the ECX register being used? Help would be greatly appreciated. Edit 2010-04-19 17:42 Could it be that the ECX register needs to be preserved on entry and restored once the function exits? Is the this pointer required by C++? I'm probably just reaching at the moment based on some intense Google searches. I found something related, but it seems to be dealing with the reverse of this issue.

    Read the article

  • Assigning two strings together getting Access Read Violation

    - by Jay Bell
    I am trying to pass a string to a class mutator and set the private member to that string here is the code that is sending the string void parseTradePairs(Exchange::Currency *curr, std::string *response, int begin, int exit) { int start; int end; string temp; string dataResponse; CURL *tempCurl; initializeCurl(tempCurl); int location = response->find("marketid", begin); if(location <= exit) { start = location + 11; begin = response->find("label", start); end = begin - start - 3; findStrings(start, end, temp, response); getMarketInfo(tempCurl, temp, dataResponse); curr->_coin->setExch(temp); // here is the line of code that is sending the string dataResponse >> *(curr->_coin); curr->_next = new Exchange::Currency(curr, curr->_position + 1); parseTradePairs(curr->_next, response, begin, exit); } } and here is the mutator within the coin class that is receiving the string and assigning it to _exch void Coin::setExch(string exch) { _exch = exch; } I have stepped through it and made sure that exch has the string in it. "105" but soon as it hits _exch = exch; I get the reading violation. I tried passing as pointer as well. I do not believe it should go out of scope. and the string variable in the class is initialized to zero in the default constructor but again that should matter unless I am trying to read from it instead of writing to it. /* defualt constructor */ Coin::Coin() { _id = ""; _label = ""; _code= ""; _name = ""; _marketCoin = ""; _volume = 0; _last = 0; _exch = ""; } Exchange::Exchange(std::string str) { _exch = str; _currencies = new Currency; std::string pair; std::string response; CURL *curl; initializeCurl(curl); getTradePairs(curl, response); int exit = response.find_last_of("marketid"); parseTradePairs(_currencies, &response, 0, exit); } int main(void) { CURL *curl; string str; string id; Coin coin1; initializeCurl(curl); Exchange ex("cryptsy"); curl_easy_cleanup(curl); system("pause"); return 0; } class Exchange { public: typedef struct Currency { Currency(Coin *coin, Currency *next, Currency *prev, int position) : _coin(coin), _next(next), _prev(prev), _position(position) {} Currency(Currency *prev, int position) : _prev(prev), _position(position), _next(NULL), _coin(&Coin()){} Currency() : _next(NULL), _prev(NULL), _position(0) {} Coin *_coin; Currency *_next; Currency *_prev; int _position; }; /* constructor and destructor */ Exchange(); Exchange(std::string str); ~Exchange(); /* Assignment operator */ Exchange& operator =(const Exchange& copyExchange); /* Parse Cryptsy Pairs */ friend void parseTradePairs(Currency *curr, std::string *response, int begin, int exit); private: std::string _exch; Currency *_currencies; }; here is what i changed it to to fix it. typedef struct Currency { Currency(Coin *coin, Currency *next, Currency *prev, int position) : _coin(coin), _next(next), _prev(prev), _position(position) {} Currency(Currency *prev, int position) : _prev(prev), _position(position), _next(NULL), _coin(&Coin()){} Currency() { _next = NULL; _prev = NULL; _position = 0; _coin = new Coin(); } Coin *_coin; Currency *_next; Currency *_prev; int _position; };

    Read the article

  • Why is my Pre to Postfix code not working?

    - by Anthony Glyadchenko
    For a class assignment, I have to use two stacks in C++ to make an equation to be converted to its left to right equivalent: 2+4*(3+4*8) -- 35*4+2 -- 142 Here is the main code: #include <iostream> #include <cstring> #include "ctStack.h" using namespace std; int main (int argc, char * const argv[]) { string expression = "2+4*2"; ctstack *output = new ctstack(expression.length()); ctstack *stack = new ctstack(expression.length()); bool previousIsANum = false; for(int i = 0; i < expression.length(); i++){ switch (expression[i]){ case '(': previousIsANum = false; stack->cmstackPush(expression[i]); break; case ')': previousIsANum = false; char x; while (x != '('){ stack->cmstackPop(x); output->cmstackPush(x); } break; case '0': case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '9': cout << "A number" << endl; previousIsANum = true; output->cmstackPush(expression[i]); break; case '+': previousIsANum = false; cout << "+" << endl; break; case '-': previousIsANum = false; cout << "-" << endl; break; case '*': previousIsANum = false; cout << "*" << endl; break; case '/': previousIsANum = false; cout << "/" << endl; break; default: break; } } char i = ' '; while (stack->ltopOfStack > 0){ stack->cmstackPop(i); output->cmstackPush(i); cout << i << endl; } return 0; } Here is the stack code (watch out!): #include <cstdio> #include <assert.h> #include <new.h> #include <stdlib.h> #include <iostream> class ctstack { private: long* lpstack ; // the stack itself long ltrue ; // constructor sets to 1 long lfalse ; // constructor sets to 0 // offset to top of the stack long lmaxEleInStack ; // maximum possible elements of stack public: long ltopOfStack ; ctstack ( long lnbrOfEleToAllocInStack ) { // Constructor lfalse = 0 ; // set to zero ltrue = 1 ; // set to one assert ( lnbrOfEleToAllocInStack > 0 ) ; // assure positive argument ltopOfStack = -1 ; // ltopOfStack is really an index lmaxEleInStack = lnbrOfEleToAllocInStack ; // set lmaxEleInStack to max ele lpstack = new long [ lmaxEleInStack ] ; // allocate stack assert ( lpstack ) ; // assure new succeeded } ~ctstack ( ) { // Destructor delete [ ] lpstack ; // Delete the stack itself } ctstack& operator= ( const ctstack& ctoriginStack) { // Assignment if ( this == &ctoriginStack ) // verify x not assigned to x return *this ; if ( this -> lmaxEleInStack < ctoriginStack . lmaxEleInStack ) { // if destination stack is smaller than delete [ ] this -> lpstack ; // original stack, delete dest and alloc this -> lpstack = // sufficient memory new long [ ctoriginStack . lmaxEleInStack ] ; assert ( this -> lpstack ) ; // assure new succeeded // reset stack size attribute this -> lmaxEleInStack = ctoriginStack . lmaxEleInStack ; } // copy original to destination stack for ( long i = 0 ; i < ctoriginStack . lmaxEleInStack ; i ++ ) *( this -> lpstack + i ) = *( ctoriginStack . lpstack + i ) ; this -> ltopOfStack = ctoriginStack . ltopOfStack ; // reset stack position attribute return *this ; } long cmstackPush (char lplaceInStack ) { // Push Method if ( ltopOfStack == lmaxEleInStack - 1 ) // stack is full can't add element return lfalse ; ltopOfStack ++ ; // acquire free slot *(lpstack + ltopOfStack ) = lplaceInStack ; // add element return ltrue ; // any number other than zero is true } long cmstackPop (char& lretrievedStackEle ) { // Pop Method if ( ltopOfStack < 0 ) { // stack has no elements lretrievedStackEle = -1 ; // dummy element return lfalse ; } lretrievedStackEle = *( lpstack + ltopOfStack ) ; // stack has element -- return it ltopOfStack -- ; // stack is pop'd return ltrue ; // any number other than zero is true } long cmstackLookAtTop (char& lretrievedStackEle ) { // Pop Method if ( ltopOfStack < 0 ) { // stack has no elements lretrievedStackEle = -1 ; // dummy element return lfalse ; } lretrievedStackEle = *( lpstack + ltopOfStack ) ; // stack has element -- return it return ltrue ; // any number other than zero is true } long cmstackHasAnEle (char& lretrievedTopOfStack ) { // Has element method lretrievedTopOfStack = ltopOfStack ; return ltopOfStack < 0 ? lfalse : ltrue ; // 0 - false stack does not have any ele } // 1 - true stack has at least one element long cmstackMaxNbrOfEle (char& lretrievedMaxStackEle ) { // Maximum element method lretrievedMaxStackEle = lmaxEleInStack ; // return stack size in reference var return ltrue ; // Return Maximum Size of Stack } } ; Thanks, Anthony.

    Read the article

  • Different behavior of functors (copies, assignments) in VS2010 (compared with VS2005)

    - by Patrick
    When moving from VS2005 to VS2010 we noticed a performance decrease, which seemed to be caused by additional copies of a functor. The following code illustrates the problem. It is essential to have a map where the value itself is a set. On both the map and the set we defined a comparison functor (which is templated in the example). #include <iostream> #include <map> #include <set> class A { public: A(int i, char c) : m_i(i), m_c(c) { std::cout << "Construct object " << m_c << m_i << std::endl; } A(const A &a) : m_i(a.m_i), m_c(a.m_c) { std::cout << "Copy object " << m_c << m_i << std::endl; } ~A() { std::cout << "Destruct object " << m_c << m_i << std::endl; } void operator= (const A &a) { m_i = a.m_i; m_c = a.m_c; std::cout << "Assign object " << m_c << m_i << std::endl; } int m_i; char m_c; }; class B : public A { public: B(int i) : A(i, 'B') { } static const char s_c = 'B'; }; class C : public A { public: C(int i) : A(i, 'C') { } static const char s_c = 'C'; }; template <class X> class compareA { public: compareA() : m_i(999) { std::cout << "Construct functor " << X::s_c << m_i << std::endl; } compareA(const compareA &a) : m_i(a.m_i) { std::cout << "Copy functor " << X::s_c << m_i << std::endl; } ~compareA() { std::cout << "Destruct functor " << X::s_c << m_i << std::endl; } void operator= (const compareA &a) { m_i = a.m_i; std::cout << "Assign functor " << X::s_c << m_i << std::endl; } bool operator() (const X &x1, const X &x2) const { std::cout << "Comparing object " << x1.m_i << " with " << x2.m_i << std::endl; return x1.m_i < x2.m_i; } private: int m_i; }; typedef std::set<C, compareA<C> > SetTest; typedef std::map<B, SetTest, compareA<B> > MapTest; int main() { int i = 0; std::cout << "--- " << i++ << std::endl; MapTest mapTest; std::cout << "--- " << i++ << std::endl; SetTest &setTest = mapTest[0]; std::cout << "--- " << i++ << std::endl; } If I compile this code with VS2005 I get the following output: --- 0 Construct functor B999 Copy functor B999 Copy functor B999 Destruct functor B999 Destruct functor B999 --- 1 Construct object B0 Construct functor C999 Copy functor C999 Copy functor C999 Destruct functor C999 Destruct functor C999 Copy object B0 Copy functor C999 Copy functor C999 Copy functor C999 Destruct functor C999 Destruct functor C999 Copy object B0 Copy functor C999 Copy functor C999 Copy functor C999 Destruct functor C999 Destruct functor C999 Destruct functor C999 Destruct object B0 Destruct functor C999 Destruct object B0 --- 2 If I compile this with VS2010, I get the following output: --- 0 Construct functor B999 Copy functor B999 Copy functor B999 Destruct functor B999 Destruct functor B999 --- 1 Construct object B0 Construct functor C999 Copy functor C999 Copy functor C999 Destruct functor C999 Destruct functor C999 Copy object B0 Copy functor C999 Copy functor C999 Copy functor C999 Destruct functor C999 Destruct functor C999 Copy functor C999 Assign functor C999 Assign functor C999 Destruct functor C999 Copy object B0 Copy functor C999 Copy functor C999 Copy functor C999 Destruct functor C999 Destruct functor C999 Copy functor C999 Assign functor C999 Assign functor C999 Destruct functor C999 Destruct functor C999 Destruct object B0 Destruct functor C999 Destruct object B0 --- 2 The output for the first statement (constructing the map) is identical. The output for the second statement (creating the first element in the map and getting a reference to it), is much bigger in the VS2010 case: Copy constructor of functor: 10 times vs 8 times Assignment of functor: 2 times vs. 0 times Destructor of functor: 10 times vs 8 times My questions are: Why does the STL copy a functor? Isn't it enough to construct it once for every instantiation of the set? Why is the functor constructed more in the VS2010 case than in the VS2005 case? (didn't check VS2008) And why is it assigned two times in VS2010 and not in VS2005? Are there any tricks to avoid the copy of functors? I saw a similar question at http://stackoverflow.com/questions/2216041/prevent-unnecessary-copies-of-c-functor-objects but I'm not sure that's the same question. Thanks in advance, Patrick

    Read the article

  • C++ simple logging class with UTF-8 output [code example]

    - by Andrew
    Hello everyone, I was working on one of my academic projects and for the first time I needed pure C++ without GUI. After googling for a while, I did not find any simple and easy to use implementation for logging and created my own. This is a simple implementation with iostreams that logs messages to screen and to the file simultaneously. I was thinking of using templates but then I realized that I do not expect any changes and removed that. It is modified std::wostream with two added modifiers: 1. TimeStamp - prints time-stamp 2. LogMode(LogModes) - switches output: file only, screen only, file+screen. *Boost::utf8_codecvt_facet* is used for UTF-8 output. // ############################################################################ // # Name: MyLog.h # // # Purpose: Logging Class Header # // # Author: Andrew Drach # // # Modified by: <somebody> # // # Created: 03/21/10 # // # SVN-ID: $Id$ # // # Copyright: (c) 2010 Andrew Drach # // # Licence: <license> # // ############################################################################ #ifndef INCLUDED_MYLOG_H #define INCLUDED_MYLOG_H // headers -------------------------------------------------------------------- #include <string> #include <iostream> #include <fstream> #include <exception> #include <boost/program_options/detail/utf8_codecvt_facet.hpp> using namespace std; // definitions ---------------------------------------------------------------- // ---------------------------------------------------------------------------- // DblBuf class // Splits up output stream into two // Inspired by http://wordaligned.org/articles/cpp-streambufs // ---------------------------------------------------------------------------- class DblBuf : public wstreambuf { private: // private member declarations DblBuf(); wstreambuf *bf1; wstreambuf *bf2; virtual int_type overflow(int_type ch) { int_type eof = traits_type::eof(); int_type not_eof = !eof; if ( traits_type::eq_int_type(ch,eof) ) return not_eof; else { char_type ch1 = traits_type::to_char_type(ch); int_type r1( bf1on ? bf1->sputc(ch1) : not_eof ); int_type r2( bf2on ? bf2->sputc(ch1) : not_eof ); return (traits_type::eq_int_type(r1,eof) || traits_type::eq_int_type(r2,eof) ) ? eof : ch; } } virtual int sync() { int r1( bf1on ? bf1->pubsync() : NULL ); int r2( bf2on ? bf2->pubsync() : NULL ); return (r1 == 0 && r2 == 0) ? 0 : -1; } public: // public member declarations explicit DblBuf(wstreambuf *bf1, wstreambuf *bf2) : bf1(bf1), bf2(bf2) { if (bf1) bf1on = true; else bf1on = false; if (bf2) bf2on = true; else bf2on = false; } bool bf1on; bool bf2on; }; // ---------------------------------------------------------------------------- // logstream class // Wrapper for a standard wostream with access to modified buffer // ---------------------------------------------------------------------------- class logstream : public wostream { private: // private member declarations logstream(); public: // public member declarations DblBuf *buf; explicit logstream(wstreambuf *StrBuf, bool isStd = false) : wostream(StrBuf, isStd), buf((DblBuf*)StrBuf) {} }; // ---------------------------------------------------------------------------- // Logging mode Class // ---------------------------------------------------------------------------- enum LogModes{LogToFile=1, LogToScreen, LogToBoth}; class LogMode { private: // private member declarations LogMode(); short mode; public: // public member declarations LogMode(short mode1) : mode(mode1) {} logstream& operator()(logstream &stream1) { switch(mode) { case LogToFile: stream1.buf->bf1on = true; stream1.buf->bf2on = false; break; case LogToScreen: stream1.buf->bf1on = false; stream1.buf->bf2on = true; break; case LogToBoth: stream1.buf->bf1on = true; stream1.buf->bf2on = true; } return stream1; } }; logstream& operator<<(logstream &out, LogMode mode) { return mode(out); } wostream& TimeStamp1(wostream &out1) { time_t time1; struct tm timeinfo; wchar_t timestr[512]; // Get current time and convert it to a string time(&time1); localtime_s (&timeinfo, &time1); wcsftime(timestr, 512,L"[%Y-%b-%d %H:%M:%S %p] ",&timeinfo); return out1 << timestr; } // ---------------------------------------------------------------------------- // MyLog class // Logs events to both file and screen // ---------------------------------------------------------------------------- class MyLog { private: // private member declarations MyLog(); auto_ptr<DblBuf> buf; string mErrorMsg1; string mErrorMsg2; string mErrorMsg3; string mErrorMsg4; public: // public member declarations explicit MyLog(string FileName1, wostream *ScrLog1, locale utf8locale1); ~MyLog(); void NewEvent(wstring str1, bool TimeStamp = true); string FileName; wostream *ScrLog; wofstream File; auto_ptr<logstream> Log; locale utf8locale; }; // ---------------------------------------------------------------------------- // MyLog constructor // ---------------------------------------------------------------------------- MyLog::MyLog(string FileName1, wostream *ScrLog1, locale utf8locale1) : // ctors mErrorMsg1("Failed to open file for application logging! []"), mErrorMsg2("Failed to write BOM! []"), mErrorMsg3("Failed to write to file! []"), mErrorMsg4("Failed to close file! []"), FileName(FileName1), ScrLog(ScrLog1), utf8locale(utf8locale1), File(FileName1.c_str()) { // Adjust error strings mErrorMsg1.insert(mErrorMsg1.length()-1,FileName1); mErrorMsg2.insert(mErrorMsg2.length()-1,FileName1); mErrorMsg3.insert(mErrorMsg3.length()-1,FileName1); mErrorMsg4.insert(mErrorMsg4.length()-1,FileName1); // check for file open errors if ( !File ) throw ofstream::failure(mErrorMsg1); // write UTF-8 BOM File << wchar_t(0xEF) << wchar_t(0xBB) << wchar_t(0xBF); // switch locale to UTF-8 File.imbue(utf8locale); // check for write errors if ( File.bad() ) throw ofstream::failure(mErrorMsg2); buf.reset( new DblBuf(File.rdbuf(),ScrLog->rdbuf()) ); Log.reset( new logstream(&*buf) ); } // ---------------------------------------------------------------------------- // MyLog destructor // ---------------------------------------------------------------------------- MyLog::~MyLog() { *Log << TimeStamp1 << "Log finished." << endl; // clean up objects Log.reset(); buf.reset(); File.close(); // check for file close errors if ( File.bad() ) throw ofstream::failure(mErrorMsg4); } //--------------------------------------------------------------------------- #endif // INCLUDED_MYLOG_H Tested on MSVC 2008, boost 1.42. I do not know if this is the right place to share it. Hope it helps anybody. Feel free to make it better.

    Read the article

  • Optimizing sorting container of objects with heap-allocated buffers - how to avoid hard-copying buff

    - by Kache4
    I was making sure I knew how to do the op= and copy constructor correctly in order to sort() properly, so I wrote up a test case. After getting it to work, I realized that the op= was hard-copying all the data_. I figure if I wanted to sort a container with this structure (its elements have heap allocated char buffer arrays), it'd be faster to just swap the pointers around. Is there a way to do that? Would I have to write my own sort/swap function? #include <deque> //#include <string> //#include <utility> //#include <cstdlib> #include <cstring> #include <iostream> //#include <algorithm> // I use sort(), so why does this still compile when commented out? #include <boost/filesystem.hpp> #include <boost/foreach.hpp> using namespace std; namespace fs = boost::filesystem; class Page { public: // constructor Page(const char* path, const char* data, int size) : path_(fs::path(path)), size_(size), data_(new char[size]) { // cout << "Creating Page..." << endl; strncpy(data_, data, size); // cout << "done creating Page..." << endl; } // copy constructor Page(const Page& other) : path_(fs::path(other.path())), size_(other.size()), data_(new char[other.size()]) { // cout << "Copying Page..." << endl; strncpy(data_, other.data(), size_); // cout << "done copying Page..." << endl; } // destructor ~Page() { delete[] data_; } // accessors const fs::path& path() const { return path_; } const char* data() const { return data_; } int size() const { return size_; } // operators Page& operator = (const Page& other) { if (this == &other) return *this; char* newImage = new char[other.size()]; strncpy(newImage, other.data(), other.size()); delete[] data_; data_ = newImage; path_ = fs::path(other.path()); size_ = other.size(); return *this; } bool operator < (const Page& other) const { return path_ < other.path(); } private: fs::path path_; int size_; char* data_; }; class Book { public: Book(const char* path) : path_(fs::path(path)) { cout << "Creating Book..." << endl; cout << "pushing back #1" << endl; pages_.push_back(Page("image1.jpg", "firstImageData", 14)); cout << "pushing back #3" << endl; pages_.push_back(Page("image3.jpg", "thirdImageData", 14)); cout << "pushing back #2" << endl; pages_.push_back(Page("image2.jpg", "secondImageData", 15)); cout << "testing operator <" << endl; cout << pages_[0].path().string() << (pages_[0] < pages_[1]? " < " : " > ") << pages_[1].path().string() << endl; cout << pages_[1].path().string() << (pages_[1] < pages_[2]? " < " : " > ") << pages_[2].path().string() << endl; cout << pages_[0].path().string() << (pages_[0] < pages_[2]? " < " : " > ") << pages_[2].path().string() << endl; cout << "sorting" << endl; BOOST_FOREACH (Page p, pages_) cout << p.path().string() << endl; sort(pages_.begin(), pages_.end()); cout << "done sorting\n"; BOOST_FOREACH (Page p, pages_) cout << p.path().string() << endl; cout << "checking datas" << endl; BOOST_FOREACH (Page p, pages_) { char data[p.size() + 1]; strncpy((char*)&data, p.data(), p.size()); data[p.size()] = '\0'; cout << p.path().string() << " " << data << endl; } cout << "done Creating Book" << endl; } private: deque<Page> pages_; fs::path path_; }; int main() { Book* book = new Book("/some/path/"); }

    Read the article

  • Need help with copy constructor for very basic implementation of singly linked lists

    - by Jesus
    Last week, we created a program that manages sets of strings, using classes and vectors. I was able to complete this 100%. This week, we have to replace the vector we used to store strings in our class with simple singly linked lists. The function basically allows users to declare sets of strings that are empty, and sets with only one element. In the main file, there is a vector whose elements are a struct that contain setName and strSet (class). HERE IS MY PROBLEM: It deals with the copy constructor of the class. When I remove/comment out the copy constructor, I can declare as many empty or single sets as I want, and output their values without a problem. But I know I will obviously need the copy constructor for when I implement the rest of the program. When I leave the copy constructor in, I can declare one set, either single or empty, and output its value. But if I declare a 2nd set, and i try to output either of the first two sets, i get a Segmentation Fault. Moreover, if i try to declare more then 2 sets, I get a Segmentation Fault. Any help would be appreciated!! Here is my code for a very basic implementation of everything: Here is the setcalc.cpp: (main file) #include <iostream> #include <cctype> #include <cstring> #include <string> #include "help.h" #include "strset2.h" using namespace std; // Declares of structure to hold all the sets defined struct setsOfStr { string nameOfSet; strSet stringSet; }; // Checks if the set name inputted is unique bool isSetNameUnique( vector<setsOfStr> strSetArr, string setName) { for(unsigned int i = 0; i < strSetArr.size(); i++) { if( strSetArr[i].nameOfSet == setName ) { return false; } } return true; } int main(int argc, char *argv[]) { char commandChoice; // Declares a vector with our declared structure as the type vector<setsOfStr> strSetVec; string setName; string singleEle; // Sets a loop that will constantly ask for a command until 'q' is typed while (1) { // declaring a set to be empty if(commandChoice == 'd') { cin >> setName; // Check that the set name inputted is unique if (isSetNameUnique(strSetVec, setName) == true) { strSet emptyStrSet; setsOfStr set1; set1.nameOfSet = setName; set1.stringSet = emptyStrSet; strSetVec.push_back(set1); } else { cerr << "ERROR: Re-declaration of set '" << setName << "'\n"; } } // declaring a set to be a singleton else if(commandChoice == 's') { cin >> setName; cin >> singleEle; // Check that the set name inputted is unique if (isSetNameUnique(strSetVec, setName) == true) { strSet singleStrSet(singleEle); setsOfStr set2; set2.nameOfSet = setName; set2.stringSet = singleStrSet; strSetVec.push_back(set2); } else { cerr << "ERROR: Re-declaration of set '" << setName << "'\n"; } } // using the output function else if(commandChoice == 'o') { cin >> setName; if(isSetNameUnique(strSetVec, setName) == false) { // loop through until the set name is matched and call output on its strSet for(unsigned int k = 0; k < strSetVec.size(); k++) { if( strSetVec[k].nameOfSet == setName ) { (strSetVec[k].stringSet).output(); } } } else { cerr << "ERROR: No such set '" << setName << "'\n"; } } // quitting else if(commandChoice == 'q') { break; } else { cerr << "ERROR: Ignoring bad command: '" << commandChoice << "'\n"; } } return 0; } Here is the strSet2.h: #ifndef _STRSET_ #define _STRSET_ #include <iostream> #include <vector> #include <string> struct node { std::string s1; node * next; }; class strSet { private: node * first; public: strSet (); // Create empty set strSet (std::string s); // Create singleton set strSet (const strSet &copy); // Copy constructor // will implement destructor later void output() const; strSet& operator = (const strSet& rtSide); // Assignment }; // End of strSet class #endif // _STRSET_ And here is the strSet2.cpp (implementation of class) #include <iostream> #include <vector> #include <string> #include "strset2.h" using namespace std; strSet::strSet() { first = NULL; } strSet::strSet(string s) { node *temp; temp = new node; temp->s1 = s; temp->next = NULL; first = temp; } strSet::strSet(const strSet& copy) { cout << "copy-cst\n"; node *n = copy.first; node *prev = NULL; while (n) { node *newNode = new node; newNode->s1 = n->s1; newNode->next = NULL; if (prev) { prev->next = newNode; } else { first = newNode; } prev = newNode; n = n->next; } } void strSet::output() const { if(first == NULL) { cout << "Empty set\n"; } else { node *temp; temp = first; while(1) { cout << temp->s1 << endl; if(temp->next == NULL) break; temp = temp->next; } } } strSet& strSet::operator = (const strSet& rtSide) { first = rtSide.first; return *this; }

    Read the article

  • Linked List manipulation, issues retrieving data c++

    - by floatfil
    I'm trying to implement some functions to manipulate a linked list. The implementation is a template typename T and the class is 'List' which includes a 'head' pointer and also a struct: struct Node { // the node in a linked list T* data; // pointer to actual data, operations in T Node* next; // pointer to a Node }; Since it is a template, and 'T' can be any data, how do I go about checking the data of a list to see if it matches the data input into the function? The function is called 'retrieve' and takes two parameters, the data and a pointer: bool retrieve(T target, T*& ptr); // This is the prototype we need to use for the project "bool retrieve : similar to remove, but not removed from list. If there are duplicates in the list, the first one encountered is retrieved. Second parameter is unreliable if return value is false. E.g., " Employee target("duck", "donald"); success = company1.retrieve(target, oneEmployee); if (success) { cout << "Found in list: " << *oneEmployee << endl; } And the function is called like this: company4.retrieve(emp3, oneEmployee) So that when you cout *oneEmployee, you'll get the data of that pointer (in this case the data is of type Employee). (Also, this is assuming all data types have the apropriate overloaded operators) I hope this makes sense so far, but my issue is in comparing the data in the parameter and the data while going through the list. (The data types that we use all include overloads for equality operators, so oneData == twoData is valid) This is what I have so far: template <typename T> bool List<T>::retrieve(T target , T*& ptr) { List<T>::Node* dummyPtr = head; // point dummy pointer to what the list's head points to for(;;) { if (*dummyPtr->data == target) { // EDIT: it now compiles, but it breaks here and I get an Access Violation error. ptr = dummyPtr->data; // set the parameter pointer to the dummy pointer return true; // return true } else { dummyPtr = dummyPtr->next; // else, move to the next data node } } return false; } Here is the implementation for the Employee class: //-------------------------- constructor ----------------------------------- Employee::Employee(string last, string first, int id, int sal) { idNumber = (id >= 0 && id <= MAXID? id : -1); salary = (sal >= 0 ? sal : -1); lastName = last; firstName = first; } //-------------------------- destructor ------------------------------------ // Needed so that memory for strings is properly deallocated Employee::~Employee() { } //---------------------- copy constructor ----------------------------------- Employee::Employee(const Employee& E) { lastName = E.lastName; firstName = E.firstName; idNumber = E.idNumber; salary = E.salary; } //-------------------------- operator= --------------------------------------- Employee& Employee::operator=(const Employee& E) { if (&E != this) { idNumber = E.idNumber; salary = E.salary; lastName = E.lastName; firstName = E.firstName; } return *this; } //----------------------------- setData ------------------------------------ // set data from file bool Employee::setData(ifstream& inFile) { inFile >> lastName >> firstName >> idNumber >> salary; return idNumber >= 0 && idNumber <= MAXID && salary >= 0; } //------------------------------- < ---------------------------------------- // < defined by value of name bool Employee::operator<(const Employee& E) const { return lastName < E.lastName || (lastName == E.lastName && firstName < E.firstName); } //------------------------------- <= ---------------------------------------- // < defined by value of inamedNumber bool Employee::operator<=(const Employee& E) const { return *this < E || *this == E; } //------------------------------- > ---------------------------------------- // > defined by value of name bool Employee::operator>(const Employee& E) const { return lastName > E.lastName || (lastName == E.lastName && firstName > E.firstName); } //------------------------------- >= ---------------------------------------- // < defined by value of name bool Employee::operator>=(const Employee& E) const { return *this > E || *this == E; } //----------------- operator == (equality) ---------------- // if name of calling and passed object are equal, // return true, otherwise false // bool Employee::operator==(const Employee& E) const { return lastName == E.lastName && firstName == E.firstName; } //----------------- operator != (inequality) ---------------- // return opposite value of operator== bool Employee::operator!=(const Employee& E) const { return !(*this == E); } //------------------------------- << --------------------------------------- // display Employee object ostream& operator<<(ostream& output, const Employee& E) { output << setw(4) << E.idNumber << setw(7) << E.salary << " " << E.lastName << " " << E.firstName << endl; return output; } I will include a check for NULL pointer but I just want to get this working and will test it on a list that includes the data I am checking. Thanks to whoever can help and as usual, this is for a course so I don't expect or want the answer, but any tips as to what might be going wrong will help immensely!

    Read the article

  • nested iterator errors

    - by Sean
    //arrayList.h #include<iostream> #include<sstream> #include<string> #include<algorithm> #include<iterator> using namespace std; template<class T> class arrayList{ public: // constructor, copy constructor and destructor arrayList(int initialCapacity = 10); arrayList(const arrayList<T>&); ~arrayList() { delete[] element; } // ADT methods bool empty() const { return listSize == 0; } int size() const { return listSize; } T& get(int theIndex) const; int indexOf(const T& theElement) const; void erase(int theIndex); void insert(int theIndex, const T& theElement); void output(ostream& out) const; // additional method int capacity() const { return arrayLength; } void reverse(); // new defined // iterators to start and end of list class iterator; class seamlessPointer; seamlessPointer begin() { return seamlessPointer(element); } seamlessPointer end() { return seamlessPointer(element + listSize); } // iterator for arrayList class iterator { public: // typedefs required by C++ for a bidirectional iterator typedef bidirectional_iterator_tag iterator_category; typedef T value_type; typedef ptrdiff_t difference_type; typedef T* pointer; typedef T& reference; // constructor iterator(T* thePosition = 0) { position = thePosition; } // dereferencing operators T& operator*() const { return *position; } T* operator->() const { return position; } // increment iterator& operator++() // preincrement { ++position; return *this; } iterator operator++(int) // postincrement { iterator old = *this; ++position; return old; } // decrement iterator& operator--() // predecrement { --position; return *this; } iterator operator--(int) // postdecrement { iterator old = *this; --position; return old; } // equality testing bool operator!=(const iterator right) const { return position != right.position; } bool operator==(const iterator right) const { return position == right.position; } protected: T* position; }; // end of iterator class class seamlessPointer: public arrayList<T>::iterator { // constructor seamlessPointer(T *thePosition) { iterator::position = thePosition; } //arithmetic operators seamlessPointer & operator+(int n) { arrayList<T>::iterator::position += n; return *this; } seamlessPointer & operator+=(int n) { arrayList<T>::iterator::position += n; return *this; } seamlessPointer & operator-(int n) { arrayList<T>::iterator::position -= n; return *this; } seamlessPointer & operator-=(int n) { arrayList<T>::iterator::position -= n; return *this; } T& operator[](int n) { return arrayList<T>::iterator::position[n]; } bool operator<(seamlessPointer &rhs) { if(int(arrayList<T>::iterator::position - rhs.position) < 0) return true; return false; } bool operator<=(seamlessPointer & rhs) { if (int(arrayList<T>::iterator::position - rhs.position) <= 0) return true; return false; } bool operator >(seamlessPointer & rhs) { if (int(arrayList<T>::iterator::position - rhs.position) > 0) return true; return false; } bool operator >=(seamlessPointer &rhs) { if (int(arrayList<T>::iterator::position - rhs.position) >= 0) return true; return false; } }; protected: // additional members of arrayList void checkIndex(int theIndex) const; // throw illegalIndex if theIndex invalid T* element; // 1D array to hold list elements int arrayLength; // capacity of the 1D array int listSize; // number of elements in list }; #endif //main.cpp #include<iostream> #include"arrayList.h" #include<fstream> #include<algorithm> #include<string> using namespace std; bool compare_nocase (string first, string second) { unsigned int i=0; while ( (i<first.length()) && (i<second.length()) ) { if (tolower(first[i])<tolower(second[i])) return true; else if (tolower(first[i])>tolower(second[i])) return false; ++i; } if (first.length()<second.length()) return true; else return false; } int main() { ifstream fin; ofstream fout; string str; arrayList<string> dict; fin.open("dictionary"); if (!fin.good()) { cout << "Unable to open file" << endl; return 1; } int k=0; while(getline(fin,str)) { dict.insert(k,str); // cout<<dict.get(k)<<endl; k++; } //sort the array sort(dict.begin, dict.end(),compare_nocase); fout.open("sortedDictionary"); if (!fout.good()) { cout << "Cannot create file" << endl; return 1; } dict.output(fout); fin.close(); return 0; } Two errors are: ..\src\test.cpp: In function 'int main()': ..\src\test.cpp:50:44: error: no matching function for call to 'sort(<unresolved overloaded function type>, arrayList<std::basic_string<char> >::seamlessPointer, bool (&)(std::string, std::string))' ..\src\/arrayList.h: In member function 'arrayList<T>::seamlessPointer arrayList<T>::end() [with T = std::basic_string<char>]': ..\src\test.cpp:50:28: instantiated from here ..\src\/arrayList.h:114:3: error: 'arrayList<T>::seamlessPointer::seamlessPointer(T*) [with T = std::basic_string<char>]' is private ..\src\/arrayList.h:49:44: error: within this context Why do I get these errors? Update I add public: in the seamlessPointer class and change begin to begin() Then I got the following errors: ..\hw3prob2.cpp:50:46: instantiated from here c:\wascana\mingw\bin\../lib/gcc/mingw32/4.5.0/include/c++/bits/stl_algo.h:5250:4: error: no match for 'operator-' in '__last - __first' ..\/arrayList.h:129:21: note: candidate is: arrayList<T>::seamlessPointer& arrayList<T>::seamlessPointer::operator-(int) [with T = std::basic_string<char>, arrayList<T>::seamlessPointer = arrayList<std::basic_string<char> >::seamlessPointer] c:\wascana\mingw\bin\../lib/gcc/mingw32/4.5.0/include/c++/bits/stl_algo.h:5252:4: instantiated from 'void std::sort(_RAIter, _RAIter, _Compare) [with _RAIter = arrayList<std::basic_string<char> >::seamlessPointer, _Compare = bool (*)(std::basic_string<char>, std::basic_string<char>)]' ..\hw3prob2.cpp:50:46: instantiated from here c:\wascana\mingw\bin\../lib/gcc/mingw32/4.5.0/include/c++/bits/stl_algo.h:2190:7: error: no match for 'operator-' in '__last - __first' ..\/arrayList.h:129:21: note: candidate is: arrayList<T>::seamlessPointer& arrayList<T>::seamlessPointer::operator-(int) [with T = std::basic_string<char>, arrayList<T>::seamlessPointer = arrayList<std::basic_string<char> >::seamlessPointer] Then I add operator -() in the seamlessPointer class ptrdiff_t operator -(seamlessPointer &rhs) { return (arrayList<T>::iterator::position - rhs.position); } Then I compile successfully. But when I run it, I found memeory can not read error. I debug and step into and found the error happens in stl function template<typename _RandomAccessIterator, typename _Distance, typename _Tp, typename _Compare> void __adjust_heap(_RandomAccessIterator __first, _Distance __holeIndex, _Distance __len, _Tp __value, _Compare __comp) { const _Distance __topIndex = __holeIndex; _Distance __secondChild = __holeIndex; while (__secondChild < (__len - 1) / 2) { __secondChild = 2 * (__secondChild + 1); if (__comp(*(__first + __secondChild), *(__first + (__secondChild - 1)))) __secondChild--; *(__first + __holeIndex) = _GLIBCXX_MOVE(*(__first + __secondChild)); ////// stop here __holeIndex = __secondChild; } Of course, there must be something wrong with the customized operators of iterator. Does anyone know the possible reason? Thank you.

    Read the article

  • A Linker Resolution Problem in a C++ Program

    - by Vlad
    We have two source files, a.cpp and b.cpp and a header file named constructions.h. We define a simple C++ class with the same name (class M, for instance) in each source file, respectively. The file a.cpp looks like this: #include "iostream" #include "constructions.h" class M { int i; public: M(): i( -1 ) { cout << "M() from a.cpp" << endl; } M( int a ) : i( a ) { cout << "M(int) from a.cpp, i: " << i << endl; } M( const M& b ) { i = b.i; cout << "M(M&) from a.cpp, i: " << i << endl; } M& operator = ( M& b ) { i = b.i; cout << "M::operator =(), i: " << i << endl; return *this; } virtual ~M(){ cout << "M::~M() from a.cpp" << endl; } operator int() { cout << "M::operator int() from a.cpp" << endl; return i; } }; void test1() { cout << endl << "Example 1" << endl; M b1; cout << "b1: " << b1 << endl; cout << endl << "Example 2" << endl; M b2 = 5; cout << "b2: " << b2 << endl; cout << endl << "Example 3" << endl; M b3(6); cout << "b3: " << b3 << endl; cout << endl << "Example 4" << endl; M b4 = b1; cout << "b4: " << b4 << endl; cout << endl << "Example 5" << endl; M b5; b5 = b2; cout << "b5: " << b5 << endl; } int main(int argc, char* argv[]) { test1(); test2(); cin.get(); return 0; } The file b.cpp looks like this: #include "iostream" #include "constructions.h" class M { public: M() { cout << "M() from b.cpp" << endl; } ~M() { cout << "M::~M() from b.cpp" << endl; } }; void test2() { M m; } Finally, the file constructions.h contains only the declaration of the function "test2()" (which is defined in "b.cpp"), so that it can be used in "a.cpp": using namespace std; void test2(); We compiled and linked these three files using either VS2005 or the GNU 4.1.0 compiler and the 2.16.91 ld linker under Suse. The results are surprising and different between the two build environments. But in both cases it looks like the linker gets confused about which definition of the class M it should use. If we comment out the definition of test2() from b.cpp and its invocation from a.cpp, then all the C++ objects created in test1() are of the type M defined in a.cpp and the program executes normally under Windows and Suse. Here is the run output under Windows: Example 1 M() from a.cpp M::operator int() from a.cpp b1: -1 Example 2 M(int) from a.cpp, i: 5 M::operator int() from a.cpp b2: 5 Example 3 M(int) from a.cpp, i: 6 M::operator int() from a.cpp b3: 6 Example 4 M(M&) from a.cpp, i: -1 M::operator int() from a.cpp b4: -1 Example 5 M() from a.cpp M::operator =(), i: 5 M::operator int() from a.cpp b5: 5 M::~M() from a.cpp M::~M() from a.cpp M::~M() from a.cpp M::~M() from a.cpp M::~M() from a.cpp If we enable the definition of test2() in "b.cpp" but comment out its invocation from main(), then the results are different. Under Suse, the C++ objects created in test1() are still of the type M defined in a.cpp and the program still seems to execute normally. The VS2005 versions behave differently in Debug or Release mode: in Debug mode, the program still seems to execute normally, but in Release mode, b1 and b5 are of the type M defined in b.cpp (as the constructor invocation proves), although the other member functions called (including the destructor), belong to M defined in a.cpp. Here is the run output for the executable built in Release mode: Example 1 M() from b.cpp M::operator int() from a.cpp b1: 4206872 Example 2 M(int) from a.cpp, i: 5 M::operator int() from a.cpp b2: 5 Example 3 M(int) from a.cpp, i: 6 M::operator int() from a.cpp b3: 6 Example 4 M(M&) from a.cpp, i: 4206872 M::operator int() from a.cpp b4: 4206872 Example 5 M() from b.cpp M::operator =(), i: 5 M::operator int() from a.cpp b5: 5 M::~M() from a.cpp M::~M() from a.cpp M::~M() from a.cpp M::~M() from a.cpp M::~M() from a.cpp Finally, if we allow the call to test2() from main, the program misbehaves in all circumstances (that is under Suse and under Windows in both Debug and Release modes). The Windows-Debug version finds a memory corruption around the variable m, defined in test2(). Here is the Windows output in Release mode (test2() seems to have created an instance of M defined in b.cpp): Example 1 M() from b.cpp M::operator int() from a.cpp b1: 4206872 Example 2 M(int) from a.cpp, i: 5 M::operator int() from a.cpp b2: 5 Example 3 M(int) from a.cpp, i: 6 M::operator int() from a.cpp b3: 6 Example 4 M(M&) from a.cpp, i: 4206872 M::operator int() from a.cpp b4: 4206872 Example 5 M() from b.cpp M::operator =(), i: 5 M::operator int() from a.cpp b5: 5 M::~M() from a.cpp M::~M() from a.cpp M::~M() from a.cpp M::~M() from a.cpp M::~M() from a.cpp M() from b.cpp M::~M() from b.cpp And here is the Suse output. The objects created in test1() are of the type M defined in a.cpp but the object created in test2() is also of the type M defined in a.cpp, unlike the object created under Windows which is of the type M defined in b.cpp. The program crashed in the end: Example 1 M() from a.cpp M::operator int() from a.cpp b1: -1 Example 2 M(int) from a.cpp, i: 5 M::operator int() from a.cpp b2: 5 Example 3 M(int) from a.cpp, i: 6 M::operator int() from a.cpp b3: 6 Example 4 M(M&) from a.cpp, i: -1 M::operator int() from a.cpp b4: -1 Example 5 M() from a.cpp M::operator =(), i: 5 M::operator int() from a.cpp b5: 5 M::~M() from a.cpp M::~M() from a.cpp M::~M() from a.cpp M::~M() from a.cpp M::~M() from a.cpp M() from a.cpp M::~M() from a.cpp Segmentation fault (core dumped) I couldn't make the angle brackets appear using Markdown, so I used quotes around the header file name iostream. Otherwise, the code could be copied verbatim and tried. It is purely scholastic. The statement cin.get() at the end of main() was included just to facilitate running the program directly from VS2005 (cause it to display the output window until we could analyze the output). We are looking for a software engineer in Sunnyvale, CA and may offer that position to the programmer capable of providing an intelligent and comprehensive explanation of these anomalies. I can be contacted at [email protected].

    Read the article

  • Query on simple C++ threadpool implementation

    - by ticketman
    Stackoverflow has been a tremendous help to me and I'd to give something back to the community. I have been implementing a simple threadpool using the tinythread C++ portable thread library, using what I have learnt from Stackoverflow. I am new to thread programming, so not that comfortable with mutexes, etc. I have a question best asked after presenting the code (which runs quite well under Linux): // ThreadPool.h class ThreadPool { public: ThreadPool(); ~ThreadPool(); // Creates a pool of threads and gets them ready to be used void CreateThreads(int numOfThreads); // Assigns a job to a thread in the pool, but doesn't start the job // Each SubmitJob call will use up one thread of the pool. // This operation can only be undone by calling StartJobs and // then waiting for the jobs to complete. On completion, // new jobs may be submitted. void SubmitJob( void (*workFunc)(void *), void *workData ); // Begins execution of all the jobs in the pool. void StartJobs(); // Waits until all jobs have completed. // The wait will block the caller. // On completion, new jobs may be submitted. void WaitForJobsToComplete(); private: enum typeOfWorkEnum { e_work, e_quit }; class ThreadData { public: bool ready; // thread has been created and is ready for work bool haveWorkToDo; typeOfWorkEnum typeOfWork; // Pointer to the work function each thread has to call. void (*workFunc)(void *); // Pointer to work data void *workData; ThreadData() : ready(false), haveWorkToDo(false) { }; }; struct ThreadArgStruct { ThreadPool *threadPoolInstance; int threadId; }; // Data for each thread ThreadData *m_ThreadData; ThreadPool(ThreadPool const&); // copy ctor hidden ThreadPool& operator=(ThreadPool const&); // assign op. hidden // Static function that provides the function pointer that a thread can call // By including the ThreadPool instance in the void * parameter, // we can use it to access other data and methods in the ThreadPool instance. static void ThreadFuncWrapper(void *arg) { ThreadArgStruct *threadArg = static_cast<ThreadArgStruct *>(arg); threadArg->threadPoolInstance->ThreadFunc(threadArg->threadId); } // The function each thread calls void ThreadFunc( int threadId ); // Called by the thread pool destructor void DestroyThreadPool(); // Total number of threads available // (fixed on creation of thread pool) int m_numOfThreads; int m_NumOfThreadsDoingWork; int m_NumOfThreadsGivenJobs; // List of threads std::vector<tthread::thread *> m_ThreadList; // Condition variable to signal each thread has been created and executing tthread::mutex m_ThreadReady_mutex; tthread::condition_variable m_ThreadReady_condvar; // Condition variable to signal each thread to start work tthread::mutex m_WorkToDo_mutex; tthread::condition_variable m_WorkToDo_condvar; // Condition variable to signal the main thread that // all threads in the pool have completed their work tthread::mutex m_WorkCompleted_mutex; tthread::condition_variable m_WorkCompleted_condvar; }; cpp file: // // ThreadPool.cpp // #include "ThreadPool.h" // This is the thread function for each thread. // All threads remain in this function until // they are asked to quit, which only happens // when terminating the thread pool. void ThreadPool::ThreadFunc( int threadId ) { ThreadData *myThreadData = &m_ThreadData[threadId]; std::cout << "Hello world: Thread " << threadId << std::endl; // Signal that this thread is ready m_ThreadReady_mutex.lock(); myThreadData->ready = true; m_ThreadReady_condvar.notify_one(); // notify the main thread m_ThreadReady_mutex.unlock(); while(true) { //tthread::lock_guard<tthread::mutex> guard(m); m_WorkToDo_mutex.lock(); while(!myThreadData->haveWorkToDo) // check for work to do m_WorkToDo_condvar.wait(m_WorkToDo_mutex); // if no work, wait here myThreadData->haveWorkToDo = false; // need to do this before unlocking the mutex m_WorkToDo_mutex.unlock(); // Do the work switch(myThreadData->typeOfWork) { case e_work: std::cout << "Thread " << threadId << ": Woken with work to do\n"; // Do work myThreadData->workFunc(myThreadData->workData); std::cout << "#Thread " << threadId << ": Work is completed\n"; break; case e_quit: std::cout << "Thread " << threadId << ": Asked to quit\n"; return; // ends the thread } // Now to signal the main thread that my work is completed m_WorkCompleted_mutex.lock(); m_NumOfThreadsDoingWork--; // Unsure if this 'if' would make the program more efficient // if(NumOfThreadsDoingWork == 0) m_WorkCompleted_condvar.notify_one(); // notify the main thread m_WorkCompleted_mutex.unlock(); } } ThreadPool::ThreadPool() { m_numOfThreads = 0; m_NumOfThreadsDoingWork = 0; m_NumOfThreadsGivenJobs = 0; } ThreadPool::~ThreadPool() { if(m_numOfThreads) { DestroyThreadPool(); delete [] m_ThreadData; } } void ThreadPool::CreateThreads(int numOfThreads) { // Check a thread pool has already been created if(m_numOfThreads > 0) return; m_NumOfThreadsGivenJobs = 0; m_NumOfThreadsDoingWork = 0; m_numOfThreads = numOfThreads; m_ThreadData = new ThreadData[m_numOfThreads]; ThreadArgStruct threadArg; for(int i=0; i<m_numOfThreads; ++i) { threadArg.threadId = i; threadArg.threadPoolInstance = this; // Creates the thread and save in a list so we can destroy it later m_ThreadList.push_back( new tthread::thread( ThreadFuncWrapper, (void *)&threadArg ) ); // It takes a little time for a thread to get established. // Best wait until it gets established before creating the next thread. m_ThreadReady_mutex.lock(); while(!m_ThreadData[i].ready) // Check if thread is ready m_ThreadReady_condvar.wait(m_ThreadReady_mutex); // If not, wait here m_ThreadReady_mutex.unlock(); } } // Adds a job to the batch, but doesn't start the job void ThreadPool::SubmitJob(void (*workFunc)(void *), void *workData) { // Check that the thread pool has been created if(!m_numOfThreads) return; if(m_NumOfThreadsGivenJobs >= m_numOfThreads) return; m_ThreadData[m_NumOfThreadsGivenJobs].workFunc = workFunc; m_ThreadData[m_NumOfThreadsGivenJobs].workData = workData; std::cout << "Submitted job " << m_NumOfThreadsGivenJobs << std::endl; m_NumOfThreadsGivenJobs++; } void ThreadPool::StartJobs() { // Check that the thread pool has been created // and some jobs have been assigned if(!m_numOfThreads || !m_NumOfThreadsGivenJobs) return; // Set 'haveworkToDo' flag for all threads m_WorkToDo_mutex.lock(); for(int i=0; i<m_NumOfThreadsGivenJobs; ++i) m_ThreadData[i].haveWorkToDo = true; m_NumOfThreadsDoingWork = m_NumOfThreadsGivenJobs; // Reset this counter so we can resubmit jobs later m_NumOfThreadsGivenJobs = 0; // Notify all threads they have work to do m_WorkToDo_condvar.notify_all(); m_WorkToDo_mutex.unlock(); } void ThreadPool::WaitForJobsToComplete() { // Check that a thread pool has been created if(!m_numOfThreads) return; m_WorkCompleted_mutex.lock(); while(m_NumOfThreadsDoingWork > 0) // Check if all threads have completed their work m_WorkCompleted_condvar.wait(m_WorkCompleted_mutex); // If not, wait here m_WorkCompleted_mutex.unlock(); } void ThreadPool::DestroyThreadPool() { std::cout << "Ask threads to quit\n"; m_WorkToDo_mutex.lock(); for(int i=0; i<m_numOfThreads; ++i) { m_ThreadData[i].haveWorkToDo = true; m_ThreadData[i].typeOfWork = e_quit; } m_WorkToDo_condvar.notify_all(); m_WorkToDo_mutex.unlock(); // As each thread terminates, catch them here for(int i=0; i<m_numOfThreads; ++i) { tthread::thread *t = m_ThreadList[i]; // Wait for thread to complete t->join(); } m_numOfThreads = 0; } Example of usage: (this calculates pi-squared/6) struct CalculationDataStruct { int inputVal; double outputVal; }; void LongCalculation( void *theSums ) { CalculationDataStruct *sums = (CalculationDataStruct *)theSums; int terms = sums->inputVal; double sum; for(int i=1; i<terms; i++) sum += 1.0/( double(i)*double(i) ); sums->outputVal = sum; } int main(int argc, char** argv) { int numThreads = 10; // Create pool ThreadPool threadPool; threadPool.CreateThreads(numThreads); // Create thread workspace CalculationDataStruct sums[numThreads]; // Set up jobs for(int i=0; i<numThreads; i++) { sums[i].inputVal = 3000*(i+1); threadPool.SubmitJob(LongCalculation, &sums[i]); } // Run the jobs threadPool.StartJobs(); threadPool.WaitForJobsToComplete(); // Print results for(int i=0; i<numThreads; i++) std::cout << "Sum of " << sums[i].inputVal << " terms is " << sums[i].outputVal << std::endl; return 0; } Question: In the ThreadPool::ThreadFunc method, would better performance be obtained if the following if statement if(NumOfThreadsDoingWork == 0) was included? Also, I'd be grateful of criticisms and ways to improve the code. At the same time, I hope the code is of use to others.

    Read the article

  • How do I improve my performance with this singly linked list struct within my program?

    - by Jesus
    Hey guys, I have a program that does operations of sets of strings. We have to implement functions such as addition and subtraction of two sets of strings. We are suppose to get it down to the point where performance if of O(N+M), where N,M are sets of strings. Right now, I believe my performance is at O(N*M), since I for each element of N, I go through every element of M. I'm particularly focused on getting the subtraction to the proper performance, as if I can get that down to proper performance, I believe I can carry that knowledge over to the rest of things I have to implement. The '-' operator is suppose to work like this, for example. Declare set1 to be an empty set. Declare set2 to be a set with { a b c } elements Declare set3 to be a set with ( b c d } elements set1 = set2 - set3 And now set1 is suppose to equal { a }. So basically, just remove any element from set3, that is also in set2. For the addition implementation (overloaded '+' operator), I also do the sorting of the strings (since we have to). All the functions work right now btw. So I was wondering if anyone could a) Confirm that currently I'm doing O(N*M) performance b) Give me some ideas/implementations on how to improve the performance to O(N+M) Note: I cannot add any member variables or functions to the class strSet or to the node structure. The implementation of the main program isn't very important, but I will post the code for my class definition and the implementation of the member functions: strSet2.h (Implementation of my class and struct) // Class to implement sets of strings // Implements operators for union, intersection, subtraction, // etc. for sets of strings // V1.1 15 Feb 2011 Added guard (#ifndef), deleted using namespace RCH #ifndef _STRSET_ #define _STRSET_ #include <iostream> #include <vector> #include <string> // Deleted: using namespace std; 15 Feb 2011 RCH struct node { std::string s1; node * next; }; class strSet { private: node * first; public: strSet (); // Create empty set strSet (std::string s); // Create singleton set strSet (const strSet &copy); // Copy constructor ~strSet (); // Destructor int SIZE() const; bool isMember (std::string s) const; strSet operator + (const strSet& rtSide); // Union strSet operator - (const strSet& rtSide); // Set subtraction strSet& operator = (const strSet& rtSide); // Assignment }; // End of strSet class #endif // _STRSET_ strSet2.cpp (implementation of member functions) #include <iostream> #include <vector> #include <string> #include "strset2.h" using namespace std; strSet::strSet() { first = NULL; } strSet::strSet(string s) { node *temp; temp = new node; temp->s1 = s; temp->next = NULL; first = temp; } strSet::strSet(const strSet& copy) { if(copy.first == NULL) { first = NULL; } else { node *n = copy.first; node *prev = NULL; while (n) { node *newNode = new node; newNode->s1 = n->s1; newNode->next = NULL; if (prev) { prev->next = newNode; } else { first = newNode; } prev = newNode; n = n->next; } } } strSet::~strSet() { if(first != NULL) { while(first->next != NULL) { node *nextNode = first->next; first->next = nextNode->next; delete nextNode; } } } int strSet::SIZE() const { int size = 0; node *temp = first; while(temp!=NULL) { size++; temp=temp->next; } return size; } bool strSet::isMember(string s) const { node *temp = first; while(temp != NULL) { if(temp->s1 == s) { return true; } temp = temp->next; } return false; } strSet strSet::operator + (const strSet& rtSide) { strSet newSet; newSet = *this; node *temp = rtSide.first; while(temp != NULL) { string newEle = temp->s1; if(!isMember(newEle)) { if(newSet.first==NULL) { node *newNode; newNode = new node; newNode->s1 = newEle; newNode->next = NULL; newSet.first = newNode; } else if(newSet.SIZE() == 1) { if(newEle < newSet.first->s1) { node *tempNext = newSet.first; node *newNode; newNode = new node; newNode->s1 = newEle; newNode->next = tempNext; newSet.first = newNode; } else { node *newNode; newNode = new node; newNode->s1 = newEle; newNode->next = NULL; newSet.first->next = newNode; } } else { node *prev = NULL; node *curr = newSet.first; while(curr != NULL) { if(newEle < curr->s1) { if(prev == NULL) { node *newNode; newNode = new node; newNode->s1 = newEle; newNode->next = curr; newSet.first = newNode; break; } else { node *newNode; newNode = new node; newNode->s1 = newEle; newNode->next = curr; prev->next = newNode; break; } } if(curr->next == NULL) { node *newNode; newNode = new node; newNode->s1 = newEle; newNode->next = NULL; curr->next = newNode; break; } prev = curr; curr = curr->next; } } } temp = temp->next; } return newSet; } strSet strSet::operator - (const strSet& rtSide) { strSet newSet; newSet = *this; node *temp = rtSide.first; while(temp != NULL) { string element = temp->s1; node *prev = NULL; node *curr = newSet.first; while(curr != NULL) { if( element < curr->s1 ) break; if( curr->s1 == element ) { if( prev == NULL) { node *duplicate = curr; newSet.first = newSet.first->next; delete duplicate; break; } else { node *duplicate = curr; prev->next = curr->next; delete duplicate; break; } } prev = curr; curr = curr->next; } temp = temp->next; } return newSet; } strSet& strSet::operator = (const strSet& rtSide) { if(this != &rtSide) { if(first != NULL) { while(first->next != NULL) { node *nextNode = first->next; first->next = nextNode->next; delete nextNode; } } if(rtSide.first == NULL) { first = NULL; } else { node *n = rtSide.first; node *prev = NULL; while (n) { node *newNode = new node; newNode->s1 = n->s1; newNode->next = NULL; if (prev) { prev->next = newNode; } else { first = newNode; } prev = newNode; n = n->next; } } } return *this; }

    Read the article

  • c++ queue template

    - by Dalton Conley
    ALright, pardon my messy code please. Below is my queue class. #include <iostream> using namespace std; #ifndef QUEUE #define QUEUE /*---------------------------------------------------------------------------- Student Class # Methods # Student() // default constructor Student(string, int) // constructor display() // out puts a student # Data Members # Name // string name Id // int id ----------------------------------------------------------------------------*/ class Student { public: Student() { } Student(string iname, int iid) { name = iname; id = iid; } void display(ostream &out) const { out << "Student Name: " << name << "\tStudent Id: " << id << "\tAddress: " << this << endl; } private: string name; int id; }; // define a typedef of a pointer to a student. typedef Student * StudentPointer; template <typename T> class Queue { public: /*------------------------------------------------------------------------ Queue Default Constructor Preconditions: none Postconditions: assigns default values for front and back to 0 description: constructs a default empty Queue. ------------------------------------------------------------------------*/ Queue() : myFront(0), myBack(0) {} /*------------------------------------------------------------------------ Copy Constructor Preconditions: requres a reference to a value for which you are copying Postconditions: assigns a copy to the parent Queue. description: Copys a queue and assigns it to the parent Queue. ------------------------------------------------------------------------*/ Queue(const T & q) { myFront = myBack = 0; if(!q.empty()) { // copy the first node myFront = myBack = new Node(q.front()); NodePointer qPtr = q.myFront->next; while(qPtr != NULL) { myBack->next = new Node(qPtr->data); myBack = myBack->next; qPtr = qPtr->next; } } } /*------------------------------------------------------------------------ Destructor Preconditions: none Postconditions: deallocates the dynamic memory for the Queue description: deletes the memory stored for a Queue. ------------------------------------------------------------------------*/ ~Queue() { NodePointer prev = myFront, ptr; while(prev != NULL) { ptr = prev->next; delete prev; prev = ptr; } } /*------------------------------------------------------------------------ Empty() Preconditions: none Postconditions: returns a boolean value. description: returns true/false based on if the queue is empty or full. ------------------------------------------------------------------------*/ bool empty() const { return (myFront == NULL); } /*------------------------------------------------------------------------ Enqueue Preconditions: requires a constant reference Postconditions: allocates memory and appends a value at the end of a queue description: ------------------------------------------------------------------------*/ void enqueue(const T & value) { NodePointer newNodePtr = new Node(value); if(empty()) { myFront = myBack = newNodePtr; newNodePtr->next = NULL; } else { myBack->next = newNodePtr; myBack = newNodePtr; newNodePtr->next = NULL; } } /*------------------------------------------------------------------------ Display Preconditions: requires a reference of type ostream Postconditions: returns the ostream value (for chaining) description: outputs the contents of a queue. ------------------------------------------------------------------------*/ void display(ostream & out) const { NodePointer ptr; ptr = myFront; while(ptr != NULL) { out << ptr->data << " "; ptr = ptr->next; } out << endl; } /*------------------------------------------------------------------------ Front Preconditions: none Postconditions: returns a value of type T description: returns the first value in the parent Queue. ------------------------------------------------------------------------*/ T front() const { if ( !empty() ) return (myFront->data); else { cerr << "*** Queue is empty -- returning garbage value ***\n"; T * temp = new(T); T garbage = * temp; delete temp; return garbage; } } /*------------------------------------------------------------------------ Dequeue Preconditions: none Postconditions: removes the first value in a queue ------------------------------------------------------------------------*/ void dequeue() { if ( !empty() ) { NodePointer ptr = myFront; myFront = myFront->next; delete ptr; if(myFront == NULL) myBack = NULL; } else { cerr << "*** Queue is empty -- " "can't remove a value ***\n"; exit(1); } } /*------------------------------------------------------------------------ pverloaded = operator Preconditions: requires a constant reference Postconditions: returns a const type T description: this allows assigning of queues to queues ------------------------------------------------------------------------*/ Queue<T> & operator=(const T &q) { // make sure we arent reassigning ourself // e.g. thisQueue = thisQueue. if(this != &q) { this->~Queue(); if(q.empty()) { myFront = myBack = NULL; } else { myFront = myBack = new Node(q.front()); NodePointer qPtr = q.myFront->next; while(qPtr != NULL) { myBack->next = new Node(qPtr->data); myBack = myBack->next; qPtr = qPtr->next; } } } return *this; } private: class Node { public: T data; Node * next; Node(T value, Node * first = 0) : data(value), next(first) {} }; typedef Node * NodePointer; NodePointer myFront, myBack, queueSize; }; /*------------------------------------------------------------------------ join Preconditions: requires 2 queue values Postconditions: appends queue2 to the end of queue1 description: this function joins 2 queues into 1. ------------------------------------------------------------------------*/ template <typename T> Queue<T> join(Queue<T> q1, Queue<T> q2) { Queue<T> q1Copy(q1), q2Copy(q2); Queue<T> jQueue; while(!q1Copy.empty()) { jQueue.enqueue(q1Copy.front()); q1Copy.dequeue(); } while(!q2Copy.empty()) { jQueue.enqueue(q2Copy.front()); q2Copy.dequeue(); } cout << jQueue << endl; return jQueue; } /*---------------------------------------------------------------------------- Overloaded << operator Preconditions: requires a constant reference and a Queue of type T Postconditions: returns the ostream (for chaining) description: this function is overloaded for outputing a queue with << ----------------------------------------------------------------------------*/ template <typename T> ostream & operator<<(ostream &out, Queue<T> &s) { s.display(out); return out; } /*---------------------------------------------------------------------------- Overloaded << operator Preconditions: requires a constant reference and a reference of type Student Postconditions: none description: this function is overloaded for outputing an object of type Student. ----------------------------------------------------------------------------*/ ostream & operator<<(ostream &out, Student &s) { s.display(out); } /*---------------------------------------------------------------------------- Overloaded << operator Preconditions: requires a constant reference and a reference of a pointer to a Student object. Postconditions: none description: this function is overloaded for outputing pointers to Students ----------------------------------------------------------------------------*/ ostream & operator<<(ostream &out, StudentPointer &s) { s->display(out); } #endif Now I'm having some issues with it. For one, when I add 0 to a queue and then I output the queue like so.. Queue<double> qdub; qdub.enqueue(0); cout << qdub << endl; That works, it will output 0. But for example, if I modify that queue in any way.. like.. assign it to a different queue.. Queue<double> qdub1; Queue<double> qdub2; qdub1.enqueue(0; qdub2 = qdub1; cout << qdub2 << endl; It will give me weird values for 0 like.. 7.86914e-316. Help on this would be much appreciated!

    Read the article

  • WMI Remote Process Starting

    - by Goober
    Scenario I've written a WMI Wrapper that seems to be quite sufficient, however whenever I run the code to start a remote process on a server, I see the process name appear in the task manager but the process itself does not start like it should (as in, I don't see the command line log window of the process that prints out what it's doing etc.) The process I am trying to start is just a C# application executable that I have written. Below is my WMI Wrapper Code and the code I am using to start running the process. Question Is the process actually running? - Even if it is only displaying the process name in the task manager and not actually launching the application to the users window? Code To Start The Process IPHostEntry hostEntry = Dns.GetHostEntry("InsertServerName"); WMIWrapper wrapper = new WMIWrapper("Insert User Name", "Insert Password", hostEntry.HostName); List<Process> processes = wrapper.GetProcesses(); foreach (Process process in processes) { if (process.Caption.Equals("MyAppName.exe")) { Console.WriteLine(process.Caption); Console.WriteLine(process.CommandLine); int processId; wrapper.StartProcess("E:\\MyData\\Data\\MyAppName.exe", out processId); Console.WriteLine(processId.ToString()); } } Console.ReadLine(); WMI Wrapper Code using System; using System.Collections.Generic; using System.Management; using System.Runtime.InteropServices; using Common.WMI.Objects; using System.Net; namespace Common.WMIWrapper { public class WMIWrapper : IDisposable { #region Constructor /// <summary> /// Creates a new instance of the wrapper /// </summary> /// <param jobName="username"></param> /// <param jobName="password"></param> /// <param jobName="server"></param> public WMIWrapper(string server) { Initialise(server); } /// <summary> /// Creates a new instance of the wrapper /// </summary> /// <param jobName="username"></param> /// <param jobName="password"></param> /// <param jobName="server"></param> public WMIWrapper(string username, string password, string server) { Initialise(username, password, server); } #endregion #region Destructor /// <summary> /// Clean up unmanaged references /// </summary> ~WMIWrapper() { Dispose(false); } #endregion #region Initialise /// <summary> /// Initialise the WMI Connection (local machine) /// </summary> /// <param name="server"></param> private void Initialise(string server) { m_server = server; // set connection options m_connectOptions = new ConnectionOptions(); IPHostEntry host = Dns.GetHostEntry(Environment.MachineName); } /// <summary> /// Initialise the WMI connection /// </summary> /// <param jobName="username">Username to connect to server with</param> /// <param jobName="password">Password to connect to server with</param> /// <param jobName="server">Server to connect to</param> private void Initialise(string username, string password, string server) { m_server = server; // set connection options m_connectOptions = new ConnectionOptions(); IPHostEntry host = Dns.GetHostEntry(Environment.MachineName); if (host.HostName.Equals(server, StringComparison.OrdinalIgnoreCase)) return; m_connectOptions.Username = username; m_connectOptions.Password = password; m_connectOptions.Impersonation = ImpersonationLevel.Impersonate; m_connectOptions.EnablePrivileges = true; } #endregion /// <summary> /// Return a list of available wmi namespaces /// </summary> /// <returns></returns> public List<String> GetWMINamespaces() { ManagementScope wmiScope = new ManagementScope(String.Format("\\\\{0}\\root", this.Server), this.ConnectionOptions); List<String> wmiNamespaceList = new List<String>(); ManagementClass wmiNamespaces = new ManagementClass(wmiScope, new ManagementPath("__namespace"), null); ; foreach (ManagementObject ns in wmiNamespaces.GetInstances()) wmiNamespaceList.Add(ns["Name"].ToString()); return wmiNamespaceList; } /// <summary> /// Return a list of available classes in a namespace /// </summary> /// <param jobName="wmiNameSpace">Namespace to get wmi classes for</param> /// <returns>List of classes in the requested namespace</returns> public List<String> GetWMIClassList(string wmiNameSpace) { ManagementScope wmiScope = new ManagementScope(String.Format("\\\\{0}\\root\\{1}", this.Server, wmiNameSpace), this.ConnectionOptions); List<String> wmiClasses = new List<String>(); ManagementObjectSearcher wmiSearcher = new ManagementObjectSearcher(wmiScope, new WqlObjectQuery("SELECT * FROM meta_Class"), null); foreach (ManagementClass wmiClass in wmiSearcher.Get()) wmiClasses.Add(wmiClass["__CLASS"].ToString()); return wmiClasses; } /// <summary> /// Get a list of wmi properties for the specified class /// </summary> /// <param jobName="wmiNameSpace">WMI Namespace</param> /// <param jobName="wmiClass">WMI Class</param> /// <returns>List of properties for the class</returns> public List<String> GetWMIClassPropertyList(string wmiNameSpace, string wmiClass) { List<String> wmiClassProperties = new List<string>(); ManagementClass managementClass = GetWMIClass(wmiNameSpace, wmiClass); foreach (PropertyData property in managementClass.Properties) wmiClassProperties.Add(property.Name); return wmiClassProperties; } /// <summary> /// Returns a list of methods for the class /// </summary> /// <param jobName="wmiNameSpace"></param> /// <param jobName="wmiClass"></param> /// <returns></returns> public List<String> GetWMIClassMethodList(string wmiNameSpace, string wmiClass) { List<String> wmiClassMethods = new List<string>(); ManagementClass managementClass = GetWMIClass(wmiNameSpace, wmiClass); foreach (MethodData method in managementClass.Methods) wmiClassMethods.Add(method.Name); return wmiClassMethods; } /// <summary> /// Retrieve the specified management class /// </summary> /// <param jobName="wmiNameSpace">Namespace of the class</param> /// <param jobName="wmiClass">Type of the class</param> /// <returns></returns> public ManagementClass GetWMIClass(string wmiNameSpace, string wmiClass) { ManagementScope wmiScope = new ManagementScope(String.Format("\\\\{0}\\root\\{1}", this.Server, wmiNameSpace), this.ConnectionOptions); ManagementClass managementClass = null; ManagementObjectSearcher wmiSearcher = new ManagementObjectSearcher(wmiScope, new WqlObjectQuery(String.Format("SELECT * FROM meta_Class WHERE __CLASS = '{0}'", wmiClass)), null); foreach (ManagementClass wmiObject in wmiSearcher.Get()) managementClass = wmiObject; return managementClass; } /// <summary> /// Get an instance of the specficied class /// </summary> /// <param jobName="wmiNameSpace">Namespace of the classes</param> /// <param jobName="wmiClass">Type of the classes</param> /// <returns>Array of management classes</returns> public ManagementObject[] GetWMIClassObjects(string wmiNameSpace, string wmiClass) { ManagementScope wmiScope = new ManagementScope(String.Format("\\\\{0}\\root\\{1}", this.Server, wmiNameSpace), this.ConnectionOptions); List<ManagementObject> wmiClasses = new List<ManagementObject>(); ManagementObjectSearcher wmiSearcher = new ManagementObjectSearcher(wmiScope, new WqlObjectQuery(String.Format("SELECT * FROM {0}", wmiClass)), null); foreach (ManagementObject wmiObject in wmiSearcher.Get()) wmiClasses.Add(wmiObject); return wmiClasses.ToArray(); } /// <summary> /// Get a full list of services /// </summary> /// <returns></returns> public List<Service> GetServices() { return GetService(null); } /// <summary> /// Get a list of services /// </summary> /// <returns></returns> public List<Service> GetService(string name) { ManagementObject[] services = GetWMIClassObjects("CIMV2", "WIN32_Service"); List<Service> serviceList = new List<Service>(); for (int i = 0; i < services.Length; i++) { ManagementObject managementObject = services[i]; Service service = new Service(managementObject); service.Status = (string)managementObject["Status"]; service.Name = (string)managementObject["Name"]; service.DisplayName = (string)managementObject["DisplayName"]; service.PathName = (string)managementObject["PathName"]; service.ProcessId = (uint)managementObject["ProcessId"]; service.Started = (bool)managementObject["Started"]; service.StartMode = (string)managementObject["StartMode"]; service.ServiceType = (string)managementObject["ServiceType"]; service.InstallDate = (string)managementObject["InstallDate"]; service.Description = (string)managementObject["Description"]; service.Caption = (string)managementObject["Caption"]; if (String.IsNullOrEmpty(name) || name.Equals(service.Name, StringComparison.OrdinalIgnoreCase)) serviceList.Add(service); } return serviceList; } /// <summary> /// Get a list of processes /// </summary> /// <returns></returns> public List<Process> GetProcesses() { return GetProcess(null); } /// <summary> /// Get a list of processes /// </summary> /// <returns></returns> public List<Process> GetProcess(uint? processId) { ManagementObject[] processes = GetWMIClassObjects("CIMV2", "WIN32_Process"); List<Process> processList = new List<Process>(); for (int i = 0; i < processes.Length; i++) { ManagementObject managementObject = processes[i]; Process process = new Process(managementObject); process.Priority = (uint)managementObject["Priority"]; process.ProcessId = (uint)managementObject["ProcessId"]; process.Status = (string)managementObject["Status"]; DateTime createDate; if (ConvertFromWmiDate((string)managementObject["CreationDate"], out createDate)) process.CreationDate = createDate.ToString("dd-MMM-yyyy HH:mm:ss"); process.Caption = (string)managementObject["Caption"]; process.CommandLine = (string)managementObject["CommandLine"]; process.Description = (string)managementObject["Description"]; process.ExecutablePath = (string)managementObject["ExecutablePath"]; process.ExecutionState = (string)managementObject["ExecutionState"]; process.MaximumWorkingSetSize = (UInt32?)managementObject ["MaximumWorkingSetSize"]; process.MinimumWorkingSetSize = (UInt32?)managementObject["MinimumWorkingSetSize"]; process.KernelModeTime = (UInt64)managementObject["KernelModeTime"]; process.ThreadCount = (UInt32)managementObject["ThreadCount"]; process.UserModeTime = (UInt64)managementObject["UserModeTime"]; process.VirtualSize = (UInt64)managementObject["VirtualSize"]; process.WorkingSetSize = (UInt64)managementObject["WorkingSetSize"]; if (processId == null || process.ProcessId == processId.Value) processList.Add(process); } return processList; } /// <summary> /// Start the specified process /// </summary> /// <param jobName="commandLine"></param> /// <returns></returns> public bool StartProcess(string command, out int processId) { processId = int.MaxValue; ManagementClass processClass = GetWMIClass("CIMV2", "WIN32_Process"); object[] objectsIn = new object[4]; objectsIn[0] = command; processClass.InvokeMethod("Create", objectsIn); if (objectsIn[3] == null) return false; processId = int.Parse(objectsIn[3].ToString()); return true; } /// <summary> /// Schedule a process on the remote machine /// </summary> /// <param name="command"></param> /// <param name="scheduleTime"></param> /// <param name="jobName"></param> /// <returns></returns> public bool ScheduleProcess(string command, DateTime scheduleTime, out string jobName) { jobName = String.Empty; ManagementClass scheduleClass = GetWMIClass("CIMV2", "Win32_ScheduledJob"); object[] objectsIn = new object[7]; objectsIn[0] = command; objectsIn[1] = String.Format("********{0:00}{1:00}{2:00}.000000+060", scheduleTime.Hour, scheduleTime.Minute, scheduleTime.Second); objectsIn[5] = true; scheduleClass.InvokeMethod("Create", objectsIn); if (objectsIn[6] == null) return false; UInt32 scheduleid = (uint)objectsIn[6]; jobName = scheduleid.ToString(); return true; } /// <summary> /// Returns the current time on the remote server /// </summary> /// <returns></returns> public DateTime Now() { ManagementScope wmiScope = new ManagementScope(String.Format("\\\\{0}\\root\\{1}", this.Server, "CIMV2"), this.ConnectionOptions); ManagementClass managementClass = null; ManagementObjectSearcher wmiSearcher = new ManagementObjectSearcher(wmiScope, new WqlObjectQuery(String.Format("SELECT * FROM Win32_LocalTime")), null); DateTime localTime = DateTime.MinValue; foreach (ManagementObject time in wmiSearcher.Get()) { UInt32 day = (UInt32)time["Day"]; UInt32 month = (UInt32)time["Month"]; UInt32 year = (UInt32)time["Year"]; UInt32 hour = (UInt32)time["Hour"]; UInt32 minute = (UInt32)time["Minute"]; UInt32 second = (UInt32)time["Second"]; localTime = new DateTime((int)year, (int)month, (int)day, (int)hour, (int)minute, (int)second); }; return localTime; } /// <summary> /// Converts a wmi date into a proper date /// </summary> /// <param jobName="wmiDate">Wmi formatted date</param> /// <returns>Date time object</returns> private static bool ConvertFromWmiDate(string wmiDate, out DateTime properDate) { properDate = DateTime.MinValue; string properDateString; // check if string is populated if (String.IsNullOrEmpty(wmiDate)) return false; wmiDate = wmiDate.Trim().ToLower().Replace("*", "0"); string[] months = new string[] { "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" }; try { properDateString = String.Format("{0}-{1}-{2} {3}:{4}:{5}.{6}", wmiDate.Substring(6, 2), months[int.Parse(wmiDate.Substring(4, 2)) - 1], wmiDate.Substring(0, 4), wmiDate.Substring(8, 2), wmiDate.Substring(10, 2), wmiDate.Substring(12, 2), wmiDate.Substring(15, 6)); } catch (InvalidCastException) { return false; } catch (ArgumentOutOfRangeException) { return false; } // try and parse the new date if (!DateTime.TryParse(properDateString, out properDate)) return false; // true if conversion successful return true; } private bool m_disposed; #region IDisposable Members /// <summary> /// Managed dispose /// </summary> public void Dispose() { Dispose(true); GC.SuppressFinalize(this); } /// <summary> /// Dispose of managed and unmanaged objects /// </summary> /// <param jobName="disposing"></param> public void Dispose(bool disposing) { if (disposing) { m_connectOptions = null; } } #endregion #region Properties private ConnectionOptions m_connectOptions; /// <summary> /// Gets or sets the management scope /// </summary> private ConnectionOptions ConnectionOptions { get { return m_connectOptions; } set { m_connectOptions = value; } } private String m_server; /// <summary> /// Gets or sets the server to connect to /// </summary> public String Server { get { return m_server; } set { m_server = value; } } #endregion } }

    Read the article

  • Tuesday + 3 = Friday? C++ Programming Problem

    - by lampshade
    Looking at the main function, we can see that I've Hard Coded the "Monday" into my setDay public function. It is easy to grab a day of the week from the user using a c-string (as I did in setDay), but how would I ask the user to add n to the day that is set, "Monday" and come up with "Thursday"? It is hard because typdef enum { INVALID, MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY, SUNDAY} doesn't interpret 9 is 0 and/or 10 as 1. #include <iostream> using std::cout; using std::endl; class DayOfTheWeek //class is encapsulation of functions and members that manipulate the data. { public: DayOfTheWeek(); // Constructor virtual ~DayOfTheWeek(); // Destructor void setDay(const char * day); // Function to set the day void printDay() const; // Function to Print the day. const char * getDay() const; // Function to get the day. const char * plusOneDay(); // Next day function const char * minusOneDay(); // Previous day function const char * addDays(int addValue); // function that adds days based on parameter value private: char * day; // variable for the days of the week. }; DayOfTheWeek::DayOfTheWeek() : day(0) { // Usually I would allocate pointer member variables // Here in the construction of the Object } const char * DayOfTheWeek::getDay() const { return day; // we can get the day simply by returning it. } const char * DayOfTheWeek::minusOneDay() { if ( strcmp( day, "Monday" ) == 0) { cout << "The day before " << day << " is "; return "Sunday"; } else if ( strcmp( day, "Tuesday" ) == 0 ) { cout << "The day before " << day << " is "; return "Monday"; } else if ( strcmp( day, "Wednesday" ) == 0 ) { cout << "The day before " << day << " is "; return "Tuesday"; } else if ( strcmp( day, "Thursday" ) == 0 ) { cout << "The day before " << day << " is "; return "Wednesday"; } else if ( strcmp( day, "Friday" ) == 0 ) { cout << "The day before " << day << " is "; return "Thursday"; } else if ( strcmp( day, "Saturday" ) == 0 ) { cout << "The day before " << day << " is "; return "Friday"; } else if ( strcmp( day, "Sunday" ) == 0 ) { cout << "The day before " << day << " is "; return "Saturday"; } else { cout << "'" << day << "'"; return "is an invalid day of the week!"; } } const char * DayOfTheWeek::plusOneDay() { if ( strcmp( day, "Monday" ) == 0) { cout << "The day after " << day << " is "; return "Tuesday"; } else if ( strcmp( day, "Tuesday" ) == 0 ) { cout << "The day after " << day << " is "; return "Wednesday"; } else if ( strcmp( day, "Wednesday" ) == 0 ) { cout << "The day after " << day << " is "; return "Thursday"; } else if ( strcmp( day, "Thursday" ) == 0 ) { cout << "The day after " << day << " is "; return "Friday"; } else if ( strcmp( day, "Friday" ) == 0 ) { cout << "The day after " << day << " is "; return "Saturday"; } else if ( strcmp( day, "Saturday" ) == 0 ) { cout << "The day after " << day << " is "; return "Sunday"; } else if ( strcmp( day, "Sunday" ) == 0 ) { cout << "The day after " << day << " is "; return "Monday"; } else { cout << "'" << day << "'"; return " is an invalid day of the week!"; } } const char * DayOfTheWeek::addDays(int addValue) { if ( addValue < 0 ) { if ( strcmp( day, "Monday" ) == 0) { cout << day << " - " << -addValue << " = "; return "Friday"; } else if ( strcmp( day, "Tuesday" ) == 0 ) { cout << day << " - " << -addValue << " = "; return "Saturday"; } else if ( strcmp( day, "Wednesday" ) == 0 ) { cout << day << " - " << -addValue << " = "; return "Sunday"; } else if ( strcmp( day, "Thursday" ) == 0 ) { cout << day << " - " << -addValue << " = "; return "Monday"; } else if ( strcmp( day, "Friday" ) == 0 ) { cout << day << " - " << -addValue << " = "; return "Tuesday"; } else if ( strcmp( day, "Saturday" ) == 0 ) { cout << day << " - " << -addValue << " = "; return "Wednesday"; } else if ( strcmp( day, "Sunday" ) == 0 ) { cout << day << " - " << -addValue << " = "; return "Thursday"; } else { cout << "'" << day << "' "; return "is an invalid day of the week! "; } } else // if our parameter is greater than 0 (positive) { if ( strcmp( day, "Monday" ) == 0) { cout << day << " + " << addValue << " = "; return "Thursday"; } else if ( strcmp( day, "Tuesday" ) == 0 ) { cout << day << " + " << addValue << " = "; return "Friday"; } else if ( strcmp( day, "Wednesday" ) == 0 ) { cout << day << " + " << addValue << " = "; return "Saturday"; } else if ( strcmp( day, "Thursday" ) == 0 ) { cout << day << " + " << addValue << " = "; return "Sunday"; } else if ( strcmp( day, "Friday" ) == 0 ) { cout << day << " + " << addValue << " = "; return "Monday"; } else if ( strcmp( day, "Saturday" ) == 0 ) { cout << day << " + " << addValue << " = "; return "Tuesday"; } else if ( strcmp( day, "Sunday" ) == 0 ) { cout << day << " + " << addValue << " = "; return "Wednesday"; } else { cout << "'" << day << "' "; return "is an invalid day of the week! "; } } } void DayOfTheWeek::printDay() const { cout << "The Value of the " << day; } void DayOfTheWeek::setDay(const char * day) { if (day) {// Here I am allocating the object member char day pointer this->day = new char[strlen(day)+1]; size_t length = strlen(day)+1; // +1 for trailing null char strcpy_s(this->day , length , day); // copying c-strings } else day = NULL; // If their was a problem with the parameter 'day' } DayOfTheWeek::~DayOfTheWeek() { delete day; // Free the memory allocated in SetDay } int main() { DayOfTheWeek MondayObject; // declare an object MondayObject.setDay("Monday"); // Call our public function 'setDay' to set a day of the week MondayObject.printDay(); // Call our public function 'printDay' to print the day we set cout << " object is " << MondayObject.getDay() << endl; // Print the value of the object cout << MondayObject.plusOneDay() << endl; cout << MondayObject.minusOneDay() << endl; cout << MondayObject.addDays(3) << endl; MondayObject.printDay(); cout << " object is still " << MondayObject.getDay() << endl; // Print the value of the object cout << MondayObject.addDays(-3) << endl; return 0; }

    Read the article

< Previous Page | 10 11 12 13 14