source: XMLIO_V2/external/include/Poco/Util/ServerApplication.h @ 80

//
// ServerApplication.h
//
// $Id: //poco/1.3/Util/include/Poco/Util/ServerApplication.h#4 $
//
// Library: Util
// Package: Application
// Module:  ServerApplication
//
// Definition of the ServerApplication class.
//
// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// Permission is hereby granted, free of charge, to any person or organization
// obtaining a copy of the software and accompanying documentation covered by
// this license (the "Software") to use, reproduce, display, distribute,
// execute, and transmit the Software, and to prepare derivative works of the
// Software, and to permit third-parties to whom the Software is furnished to
// do so, all subject to the following:
// 
// The copyright notices in the Software and this entire statement, including
// the above license grant, this restriction and the following disclaimer,
// must be included in all copies of the Software, in whole or in part, and
// all derivative works of the Software, unless such copies or derivative
// works are solely in the form of machine-executable object code generated by
// a source language processor.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//


#ifndef Util_ServerApplication_INCLUDED
#define Util_ServerApplication_INCLUDED


#include "Poco/Util/Util.h"
#include "Poco/Util/Application.h"
#include "Poco/Event.h"


namespace Poco {
namespace Util {


class Util_API ServerApplication: public Application
        /// A subclass of the Application class that is used
        /// for implementing server applications.
        ///
        /// A ServerApplication allows for the application
        /// to run as a Windows service or as a Unix daemon
        /// without the need to add extra code.
        ///
        /// For a ServerApplication to work both from the command line
        /// and as a daemon or service, a few rules must be met:
        ///   - Subsystems must be registered in the constructor.
        ///   - All non-trivial initializations must be made in the
        ///     initialize() method.
        ///   - At the end of the main() method, waitForTerminationRequest()
        ///     should be called.
        ///   - The main(argc, argv) function must look as follows:
        ///
        ///   int main(int argc, char** argv)
        ///   {
        ///       MyServerApplication app;
        ///       return app.run(argc, argv);
        ///   }
        ///
        /// The POCO_SERVER_MAIN macro can be used to implement main(argc, argv).
        /// If POCO has been built with POCO_WIN32_UTF8, POCO_SERVER_MAIN supports
        /// Unicode command line arguments.
        ///
        /// On Windows platforms, an application built on top of the
        /// ServerApplication class can be run both from the command line
        /// or as a service.
        ///
        /// To run an application as a Windows service, it must be registered
        /// with the Windows Service Control Manager (SCM). To do this, the application
        /// can be started from the command line, with the /registerService option
        /// specified. This causes the application to register itself with the
        /// SCM, and then exit. Similarly, an application registered as a service can
        /// be unregistered, by specifying the /unregisterService option.
        /// The file name of the application executable (excluding the .exe suffix)
        /// is used as the service name. Additionally, a more user-friendly name can be
        /// specified, using the /displayName option (e.g., /displayName="Demo Service").
        ///
        /// An application can determine whether it is running as a service by checking
        /// for the "application.runAsService" configuration property.
        /// 
        ///     if (config().getBool("application.runAsService", false))
        ///     {
        ///         // do service specific things
        ///     }
        ///
        /// Note that the working directory for an application running as a service
        /// is the Windows system directory (e.g., C:\Windows\system32). Take this
        /// into account when working with relative filesystem paths. Also, services
        /// run under a different user account, so an application that works when
        /// started from the command line may fail to run as a service if it depends
        /// on a certain environment (e.g., the PATH environment variable).
        ///
        /// An application registered as a Windows service can be started
        /// with the NET START <name> command and stopped with the NET STOP <name>
        /// command. Alternatively, the Services MMC applet can be used.
        ///
        /// On Unix platforms, an application built on top of the ServerApplication
        /// class can be optionally run as a daemon by giving the --daemon
        /// command line option. A daemon, when launched, immediately
        /// forks off a background process that does the actual work. After launching
        /// the background process, the foreground process exits.
        /// 
        /// After the initialization is complete, but before entering the main() method,
        /// the current working directory for the daemon process is changed to the root
        /// directory ("/"), as it is common practice for daemon processes. Therefore, be
        /// careful when working with files, as relative paths may not point to where
        /// you expect them point to.
        ///
        /// An application can determine whether it is running as a daemon by checking
        /// for the "application.runAsDaemon" configuration property.
        ///
        ///     if (config().getBool("application.runAsDaemon", false))
        ///     {
        ///         // do daemon specific things
        ///     }
        ///
        /// When running as a daemon, specifying the --pidfile option (e.g.,
        /// --pidfile=/var/run/sample.pid) may be useful to record the process ID of 
        /// the daemon in a file. The PID file will be removed when the daemon process 
        /// terminates (but not, if it crashes).
{
public:
        ServerApplication();
                /// Creates the ServerApplication.

        ~ServerApplication();
                /// Destroys the ServerApplication.
                
        bool isInteractive() const;
                /// Returns true if the application runs from the command line.
                /// Returns false if the application runs as a Unix daemon
                /// or Windows service.

        int run(int argc, char** argv);
                /// Runs the application by performing additional initializations
                /// and calling the main() method.

#if defined(POCO_WIN32_UTF8) && !defined(POCO_NO_WSTRING)
        int run(int argc, wchar_t** argv);
                /// Runs the application by performing additional initializations
                /// and calling the main() method.
                ///
                /// This Windows-specific version of init is used for passing
                /// Unicode command line arguments from wmain().
#endif

protected:
        int run();
        void waitForTerminationRequest();
        void defineOptions(OptionSet& options);
        void handleOption(const std::string& name, const std::string& value);
        static void terminate();

private:
#if defined(POCO_OS_FAMILY_UNIX)
        bool isDaemon(int argc, char** argv);
        void beDaemon();
#elif defined(POCO_OS_FAMILY_WINDOWS)
        enum Action
        {
                SRV_RUN,
                SRV_REGISTER,
                SRV_UNREGISTER
        };
        static BOOL __stdcall ConsoleCtrlHandler(DWORD ctrlType);
        static void __stdcall ServiceControlHandler(DWORD control);
#if defined(POCO_WIN32_UTF8) && !defined(POCO_NO_WSTRING)
        static void __stdcall ServiceMain(DWORD argc, LPWSTR* argv);
#else
        static void __stdcall ServiceMain(DWORD argc, LPTSTR* argv);
#endif

        bool hasConsole();
        bool isService();
        void beService();
        void registerService();
        void unregisterService();
        
        Action      _action;
        std::string _displayName;

        static Poco::Event           _terminated;
        static SERVICE_STATUS        _serviceStatus; 
        static SERVICE_STATUS_HANDLE _serviceStatusHandle; 
#endif
};


} } // namespace Poco::Util


//
// Macro to implement main()
//
#if defined(_WIN32) && defined(POCO_WIN32_UTF8)
        #define POCO_SERVER_MAIN(App) \
        int wmain(int argc, wchar_t** argv)     \
        {                                                                       \
                App app;                                                \
                return app.run(argc, argv);             \
        }
#else
        #define POCO_SERVER_MAIN(App) \
        int main(int argc, char** argv)         \
        {                                                                       \
                App app;                                                \
                return app.run(argc, argv);             \
        }
#endif


#endif // Util_ServerApplication_INCLUDED