(C++) MemcheckExample6

 

 

memcheck example 6: how to stop a Wt server is a memcheck example that tests how to stop a Wt server cleanly.

 

• Download the Qt Creator project 'CppMemcheckExample6' (zip)
• View the valgrind output of 'CppMemcheckExample6' and pressing CTRL-C (txt)
• View the valgrind output of 'CppMemcheckExample6' and calling std::exit(0) (txt)
• View the valgrind output of 'CppMemcheckExample6' and calling throw (txt)

 

This example was developed, because tools like valgrind and the profiler gprof require a program to quit without errors.

 

This web application creates four buttons, that each use a different way to let main return. Of these four buttons, two are disabled: these call methods that do not cause the application to terminate (yet). When starting the web application from command line, pressing CTRL-C is another option to cleanly terminate it.

Technical facts

 

Operating system(s) or programming environment(s)

• Lubuntu 15.04 (vivid)

IDE(s):

• Qt Creator 3.1.1

Project type:

• Console application

C++ standard:

• C++98

Compiler(s):

• G++ 4.9.2

Libraries used:

• STL: GNU ISO C++ Library, version 4.9.2

 

 

 

 

 

Qt project file: ./CppMemcheckExample6/CppMemcheckExample6.pro

 

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include(../../WebApplication.pri) include(../../Libraries/BoostAll.pri) include(../../Libraries/Wt.pri) SOURCES += main.cpp

 

 

 

 

 

./CppMemcheckExample6/main.cpp

 

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#include <Wt/WApplication> #include <Wt/WBreak> #include <Wt/WContainerWidget> //#include <Wt/WLineEdit> #include <Wt/WPushButton> //#include <Wt/WText> #include <Wt/WServer> struct ApplicationCppValgrindExample6 : public Wt::WApplication {   ApplicationCppValgrindExample6(const Wt::WEnvironment& env)   : Wt::WApplication(env)   {     this->setTitle("CppValgrindExample6");     {       Wt::WPushButton * button = new Wt::WPushButton("Call std::exit(0)");       button->clicked().connect(this,&ApplicationCppValgrindExample6::DoExit);       this->root()->addWidget(button);     }     {       Wt::WPushButton * button = new Wt::WPushButton("Call Wt::WServer::waitForShutdown and Wt::WServer::stop");       button->setEnabled(false);       button->clicked().connect(this,&ApplicationCppValgrindExample6::DoStop1);       this->root()->addWidget(button);     }     {       Wt::WPushButton * button = new Wt::WPushButton("Call Wt::WServer::stop");       button->setEnabled(false);       button->clicked().connect(this,&ApplicationCppValgrindExample6::DoStop2);       this->root()->addWidget(button);     }     {       Wt::WPushButton * button = new Wt::WPushButton("Throw");       button->clicked().connect(this,&ApplicationCppValgrindExample6::DoThrow);       this->root()->addWidget(button);     }   }   void DoExit() { std::exit(0); }   void DoStop1()   {     Wt::WServer::instance()->waitForShutdown();     Wt::WServer::instance()->stop();   }   void DoStop2() { Wt::WServer::instance()->stop(); }   void DoThrow() { throw; } }; Wt::WApplication * CreateApplication(const Wt::WEnvironment& env) {   return new ApplicationCppValgrindExample6(env); } int main(int, char *argv[]) {   //C++0x initializer list   const char * const v[7] =   {     argv[0],     "--docroot", ".",     "--http-port", "8080",     "--http-address", "0.0.0.0"   };   return WRun(7, const_cast<char**>(v), &CreateApplication); }

 

 

 

 

 

./CppMemcheckExample6/valgrind_memcheck.sh

 

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#!/bin/sh valgrind --leak-check=full -v --show-reachable=yes --log-file=valgrind_memcheck.txt ../CppValgrindExample6-build-desktop/./CppValgrindExample6