WebSVN - public - Diff - Rev 73 and 84 - /incron/tags/incron-0.5.7/appinst.h



/// Application instance class header
/**
 * \file appinst.h
 *
 * Copyright (C) 2007 Lukas Jelinek, <lukas@aiken.cz>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of one of the following licenses:
 *
 * \li 1. X11-style license (see LICENSE-X11)
 * \li 2. GNU Lesser General Public License, version 2.1 (see LICENSE-LGPL)
 * \li 3. GNU General Public License, version 2  (see LICENSE-GPL)
 *
 * If you want to help with choosing the best license for you,
 * please visit http://www.gnu.org/licenses/license-list.html.
 *
 */


#ifndef APPINST_H_
#define APPINST_H_


#include <string>


#define APPLOCK_BASEDIR "/var/run"


/// Exception class.
/**
 * This class provides information about occurred errors.
 */
class AppInstException
{
public:
  /// Constructor.
  /**
   * \param[in] iErr error number
   */
  AppInstException(int iErr) : m_iErr(iErr) {}
 
  /// Returns the error number.
  /**
   * \return error number
   */
  inline int GetErrorNumber() const
  {
    return m_iErr;
  }
 
private:
  int m_iErr; ///< error number
   
};

/// Application instance management class.
/**
 * This class is intended for application which require to
 * be running only once (one instance only). It provides some
 * methods for simple locking, signaling etc.
 */
class AppInstance
{
public:
  /// Constructor.
  /**
   * \param[in] rName application name
   * \param[in] rBase lockfile base directory
   *
   * \attention If an empty base directory is given it is replaced by
   *            the default value.
   */
  AppInstance(const std::string& rName, const std::string& rBase = APPLOCK_BASEDIR);
 
  /// Destructor.
  ~AppInstance();
 
  /// Attempts to lock the instance.
  /**
   * This method attempts to create a lockfile. If the file
   * already exists it checks whether its owner is still living.
   * If it does this method fails. Otherwise it unlinks this file
   * and re-attempts to create it.
   *
   * \return true = instance locked, false = otherwise
   */
  bool Lock();
 
  /// Unlocks the instance.
  /**
   * This method removes (unlinks) the appropriate lockfile.
   * If the instance hasn't been locked this method has no
   * effect.
   */
  void Unlock();
 
  /// Checks whether an instance of this application exists.
  /**
   * If this instance has acquired the lockfile the call will
   * be successful. Otherwise it checks for existence of
   * another running instance.
   *
   * \return true = instance exists, false = otherwise
   */
  bool Exists() const;
 
  /// Sends a signal to an instance of this application.
  /**
   * This method doesn't signal the current instance.
   *
   * \param[in] iSigNo signal number
   * \return true = success, false = otherwise
   */
  bool SendSignal(int iSigNo) const;
 
  /// Terminates an instance of this application.
  /**
   * This method doesn't terminate the current instance.
   *
   * \return true = success, false = otherwise
   */
  inline bool Terminate() const
  {
    return SendSignal(SIGTERM);
  }
 
protected:
  bool DoLock();
 
private:
  std::string m_path; ///< lock path
  bool m_fLocked;     ///< locked yes/no
};

#endif /*APPINST_H_*/
 

Rev 73	Rev 84
1		1
2	/// Application instance class header	2	/// Application instance class header
3	/**	3	/**
4	* \file appinst.h	4	* \file appinst.h
5	*	5	*
6	* Copyright (C) 2007 Lukas Jelinek, <lukas@aiken.cz>	6	* Copyright (C) 2007 Lukas Jelinek, <lukas@aiken.cz>
7	*	7	*
8	* This program is free software; you can redistribute it and/or	8	* This program is free software; you can redistribute it and/or
9	* modify it under the terms of one of the following licenses:	9	* modify it under the terms of one of the following licenses:
10	*	10	*
11	* \li 1. X11-style license (see LICENSE-X11)	11	* \li 1. X11-style license (see LICENSE-X11)
12	* \li 2. GNU Lesser General Public License, version 2.1 (see LICENSE-LGPL)	12	* \li 2. GNU Lesser General Public License, version 2.1 (see LICENSE-LGPL)
13	* \li 3. GNU General Public License, version 2 (see LICENSE-GPL)	13	* \li 3. GNU General Public License, version 2 (see LICENSE-GPL)
14	*	14	*
15	* If you want to help with choosing the best license for you,	15	* If you want to help with choosing the best license for you,
16	* please visit http://www.gnu.org/licenses/license-list.html.	16	* please visit http://www.gnu.org/licenses/license-list.html.
17	*	17	*
18	*/	18	*/
19		19
20		20
21	#ifndef APPINST_H_	21	#ifndef APPINST_H_
22	#define APPINST_H_	22	#define APPINST_H_
23		23
24		24
25	#include <string>	25	#include <string>
26		26
27		27
28	#define APPLOCK_BASEDIR "/var/run"	28	#define APPLOCK_BASEDIR "/var/run"
29		29
30		30
31	/// Exception class.	31	/// Exception class.
32	/**	32	/**
33	* This class provides information about occurred errors.	33	* This class provides information about occurred errors.
34	*/	34	*/
35	class AppInstException	35	class AppInstException
36	{	36	{
37	public:	37	public:
38	/// Constructor.	38	/// Constructor.
39	/**	39	/**
40	* \param[in] iErr error number	40	* \param[in] iErr error number
41	*/	41	*/
42	AppInstException(int iErr) : m_iErr(iErr) {}	42	AppInstException(int iErr) : m_iErr(iErr) {}
43		43
44	/// Returns the error number.	44	/// Returns the error number.
45	/**	45	/**
46	* \return error number	46	* \return error number
47	*/	47	*/
48	inline int GetErrorNumber() const	48	inline int GetErrorNumber() const
49	{	49	{
50	return m_iErr;	50	return m_iErr;
51	}	51	}
52		52
53	private:	53	private:
54	int m_iErr; ///< error number	54	int m_iErr; ///< error number
55		55
56	};	56	};
57		57
58	/// Application instance management class.	58	/// Application instance management class.
59	/**	59	/**
60	* This class is intended for application which require to	60	* This class is intended for application which require to
61	* be running only once (one instance only). It provides some	61	* be running only once (one instance only). It provides some
62	* methods for simple locking, signaling etc.	62	* methods for simple locking, signaling etc.
63	*/	63	*/
64	class AppInstance	64	class AppInstance
65	{	65	{
66	public:	66	public:
67	/// Constructor.	67	/// Constructor.
68	/**	68	/**
69	* \param[in] rName application name	69	* \param[in] rName application name
70	* \param[in] rBase lockfile base directory	70	* \param[in] rBase lockfile base directory
71	*	71	*
72	* \attention If an empty base directory is given it is replaced by	72	* \attention If an empty base directory is given it is replaced by
73	* the default value.	73	* the default value.
74	*/	74	*/
75	AppInstance(const std::string& rName, const std::string& rBase = APPLOCK_BASEDIR);	75	AppInstance(const std::string& rName, const std::string& rBase = APPLOCK_BASEDIR);
76		76
77	/// Destructor.	77	/// Destructor.
78	~AppInstance();	78	~AppInstance();
79		79
80	/// Attempts to lock the instance.	80	/// Attempts to lock the instance.
81	/**	81	/**
82	* This method attempts to create a lockfile. If the file	82	* This method attempts to create a lockfile. If the file
83	* already exists it checks whether its owner is still living.	83	* already exists it checks whether its owner is still living.
84	* If it does this method fails. Otherwise it unlinks this file	84	* If it does this method fails. Otherwise it unlinks this file
85	* and re-attempts to create it.	85	* and re-attempts to create it.
86	*	86	*
87	* \return true = instance locked, false = otherwise	87	* \return true = instance locked, false = otherwise
88	*/	88	*/
89	bool Lock();	89	bool Lock();
90		90
91	/// Unlocks the instance.	91	/// Unlocks the instance.
92	/**	92	/**
93	* This method removes (unlinks) the appropriate lockfile.	93	* This method removes (unlinks) the appropriate lockfile.
94	* If the instance hasn't been locked this method has no	94	* If the instance hasn't been locked this method has no
95	* effect.	95	* effect.
96	*/	96	*/
97	void Unlock();	97	void Unlock();
98		98
99	/// Checks whether an instance of this application exists.	99	/// Checks whether an instance of this application exists.
100	/**	100	/**
101	* If this instance has acquired the lockfile the call will	101	* If this instance has acquired the lockfile the call will
102	* be successful. Otherwise it checks for existence of	102	* be successful. Otherwise it checks for existence of
103	* another running instance.	103	* another running instance.
104	*	104	*
105	* \return true = instance exists, false = otherwise	105	* \return true = instance exists, false = otherwise
106	*/	106	*/
107	bool Exists() const;	107	bool Exists() const;
108		108
109	/// Sends a signal to an instance of this application.	109	/// Sends a signal to an instance of this application.
110	/**	110	/**
111	* This method doesn't signal the current instance.	111	* This method doesn't signal the current instance.
112	*	112	*
113	* \param[in] iSigNo signal number	113	* \param[in] iSigNo signal number
114	* \return true = success, false = otherwise	114	* \return true = success, false = otherwise
115	*/	115	*/
116	bool SendSignal(int iSigNo) const;	116	bool SendSignal(int iSigNo) const;
117		117
118	/// Terminates an instance of this application.	118	/// Terminates an instance of this application.
119	/**	119	/**
120	* This method doesn't terminate the current instance.	120	* This method doesn't terminate the current instance.
121	*	121	*
122	* \return true = success, false = otherwise	122	* \return true = success, false = otherwise
123	*/	123	*/
124	inline bool Terminate() const	124	inline bool Terminate() const
125	{	125	{
126	return SendSignal(SIGTERM);	126	return SendSignal(SIGTERM);
127	}	127	}
128		128
129	protected:	129	protected:
130	bool DoLock();	130	bool DoLock();
131		131
132	private:	132	private:
133	std::string m_path; ///< lock path	133	std::string m_path; ///< lock path
134	bool m_fLocked; ///< locked yes/no	134	bool m_fLocked; ///< locked yes/no
135	};	135	};
136		136
137	#endif /APPINST_H_/	137	#endif /APPINST_H_/
138		138

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