summaryrefslogtreecommitdiffstats
path: root/tdecore/klockfile.h
blob: be347ab56aa322334ce7b0173aa00958ea138cb0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
/*
   This file is part of the KDE libraries
   Copyright (c) 2004 Waldo Bastian <bastian@kde.org>
   
   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public
   License version 2 as published by the Free Software Foundation.
   
   This library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.
   
   You should have received a copy of the GNU Library General Public License
   along with this library; see the file COPYING.LIB.  If not, write to
   the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
   Boston, MA 02110-1301, USA.
*/

#ifndef _KLOCTDEFILE_H_
#define _KLOCTDEFILE_H_

#include <tqstring.h>
#include <tqdatetime.h>

#include <ksharedptr.h>
/**
 * The TDELockFile class provides NFS safe lockfiles.
 *
 * @author Waldo Bastian <bastian@kde.org>
 * @since 3.3
 */
class TDECORE_EXPORT TDELockFile : public TDEShared
{
public:
   typedef TDESharedPtr<TDELockFile> Ptr;

   TDELockFile(const TQString &file);

   /**
    * Destroys the object, releasing the lock if held
    **/
   ~TDELockFile();

   /**
    * Possible return values of the lock function.
    */
   enum LockResult {
     /**
      * Lock was acquired successfully
      */
     LockOK = 0, 

     /**
      * The lock could not be acquired because it is held by another process
      */
     LockFail,
     
     /**
      * The lock could not be acquired due to an error
      */
     LockError,

     /**
      * A stale lock has been detected
      */
     LockStale
   };

   enum LockOptions {
     /**
      * Return immediately, do not wait for the lock to become available
      */
     LockNoBlock = 1,
     
     /**
      * Automatically remove a lock when a lock is detected that is stale
      * for more than staleTime() seconds.
      */
     LockForce = 2
   };

   /**
    * Attempt to acquire the lock
    *
    * @param options A set of @ref LockOptions OR'ed together.
    */
   LockResult lock(int options=0);
   
   /**
    * Returns whether the lock is held or not
    */
   bool isLocked() const;
   
   /**
    * Release the lock
    */
   void unlock();

   /**
    * Return the time in seconds after which a lock is considered stale
    * The default is 30.
    */
   int staleTime() const;
   
   /**
    * Set the time in seconds after which a lock is considered stale
    */
   void setStaleTime(int _staleTime);

   /**
    * Returns the pid, hostname and appname of the process holding
    * the lock after the lock functon has returned with LockStale.
    * @returns false if the pid and hostname could not be determined
    */
   bool getLockInfo(int &pid, TQString &hostname, TQString &appname);

private:
   class TDELockFilePrivate;
   TDELockFilePrivate *d;
};

#endif