lock.cpp
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00021 #include "lock.h"
00022
00023 #include <kapplication.h>
00024 #include <kdebug.h>
00025 #include <klocale.h>
00026 #include <kstandarddirs.h>
00027 #include <ktempfile.h>
00028
00029 #include <qfile.h>
00030
00031 #include <signal.h>
00032 #include <sys/types.h>
00033 #include <sys/stat.h>
00034 #include <unistd.h>
00035
00036 using namespace KABC;
00037
00038 Lock::Lock( const QString &identifier )
00039 : mIdentifier( identifier )
00040 {
00041 mIdentifier.replace( "/", "_" );
00042 }
00043
00044 Lock::~Lock()
00045 {
00046 unlock();
00047 }
00048
00049 QString Lock::locksDir()
00050 {
00051 return locateLocal( "data", "kabc/lock/" );
00052 }
00053
00054 bool Lock::readLockFile( const QString &filename, int &pid, QString &app )
00055 {
00056 QFile file( filename );
00057 if ( !file.open( IO_ReadOnly ) ) return false;
00058
00059 QTextStream t( &file );
00060 t >> pid >> ws >> app;
00061
00062 return true;
00063 }
00064
00065 bool Lock::writeLockFile( const QString &filename )
00066 {
00067 QFile file( filename );
00068 if ( !file.open( IO_WriteOnly ) ) return false;
00069 QTextStream t( &file );
00070 t << ::getpid() << endl << QString( KGlobal::instance()->instanceName() );
00071
00072 return true;
00073 }
00074
00075 QString Lock::lockFileName() const
00076 {
00077 return locksDir() + mIdentifier + ".lock";
00078 }
00079
00080 bool Lock::lock()
00081 {
00082 kdDebug(5700) << "Lock::lock()" << endl;
00083
00084 QString lockName = lockFileName();
00085 kdDebug(5700) << "-- lock name: " << lockName << endl;
00086
00087 if ( QFile::exists( lockName ) ) {
00088 int pid;
00089 QString app;
00090
00091 if ( !readLockFile( lockFileName(), pid, app ) ) {
00092 mError = i18n("Unable to open lock file.");
00093 return false;
00094 }
00095
00096 int retval = ::kill( pid, 0 );
00097 if ( retval == -1 && errno == ESRCH ) {
00098 QFile::remove( lockName );
00099 kdWarning(5700) << "Removed stale lock file from process '" << app << "'"
00100 << endl;
00101 } else {
00102 QString identifier( mIdentifier );
00103 identifier.replace( '_', '/' );
00104
00105 mError = i18n("The resource '%1' is locked by application '%2'.")
00106 .arg( identifier ).arg( app );
00107 return false;
00108 }
00109 }
00110
00111 QString lockUniqueName;
00112 lockUniqueName = mIdentifier + kapp->randomString( 8 );
00113 mLockUniqueName = locateLocal( "data", "kabc/lock/" + lockUniqueName );
00114 kdDebug(5700) << "-- lock unique name: " << mLockUniqueName << endl;
00115
00116
00117 writeLockFile( mLockUniqueName );
00118
00119
00120 int result = ::link( QFile::encodeName( mLockUniqueName ),
00121 QFile::encodeName( lockName ) );
00122
00123 if ( result == 0 ) {
00124 mError = "";
00125 emit locked();
00126 return true;
00127 }
00128
00129
00130
00131 mError = i18n("Error");
00132 return false;
00133 }
00134
00135 bool Lock::unlock()
00136 {
00137 int pid;
00138 QString app;
00139 if ( readLockFile( lockFileName(), pid, app ) ) {
00140 if ( pid == getpid() ) {
00141 QFile::remove( lockFileName() );
00142 QFile::remove( mLockUniqueName );
00143 emit unlocked();
00144 } else {
00145 mError = i18n("Unlock failed. Lock file is owned by other process: %1 (%2)")
00146 .arg( app ).arg( QString::number( pid ) );
00147 kdDebug() << "Lock::unlock(): " << mError << endl;
00148 return false;
00149 }
00150 }
00151
00152 mError = "";
00153 return true;
00154 }
00155
00156 QString Lock::error() const
00157 {
00158 return mError;
00159 }
00160
00161 #include "lock.moc"
This file is part of the documentation for kabc Library Version 3.4.0.