/usr/include/casacore/tables/Tables/ExternalLockSync.h is in casacore-dev 2.2.0-2.
This file is owned by root:root, with mode 0o644.
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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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 | //# ExternalLockSync.h: Class to hold table lock data
//# Copyright (C) 1997,1998
//# Associated Universities, Inc. Washington DC, USA.
//#
//# This library is free software; you can redistribute it and/or modify it
//# under the terms of the GNU Library General Public License as published by
//# the Free Software Foundation; either version 2 of the License, or (at your
//# option) any later version.
//#
//# 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; if not, write to the Free Software Foundation,
//# Inc., 675 Massachusetts Ave, Cambridge, MA 02139, USA.
//#
//# Correspondence concerning AIPS++ should be addressed as follows:
//# Internet email: aips2-request@nrao.edu.
//# Postal address: AIPS++ Project Office
//# National Radio Astronomy Observatory
//# 520 Edgemont Road
//# Charlottesville, VA 22903-2475 USA
//#
//# $Id$
#ifndef TABLES_EXTERNALLOCKSYNC_H
#define TABLES_EXTERNALLOCKSYNC_H
//# Includes
#include <casacore/casa/aips.h>
#include <casacore/tables/Tables/TableLockData.h>
#include <casacore/tables/Tables/TableSyncData.h>
namespace casacore { //# NAMESPACE CASACORE - BEGIN
// <summary>
// Class to hold table lock data.
// </summary>
// <use visibility=local>
// <reviewed reviewer="UNKNOWN" date="before2004/08/25" tests="tTable" demos="">
// </reviewed>
// <prerequisite>
// <li> class <linkto class=Table>TableLock</linkto>
// </prerequisite>
// <synopsis>
// This class keeps the <src>LockFile</src> object used to do the
// actual locking/unlocking.
// It also keeps the synchronization information.
// </synopsis>
// <motivation>
// Encapsulate Table locking data.
// </motivation>
class ExternalLockSync
{
public:
// Construct from the given TableLock object.
ExternalLockSync (const TableLock& lockOptions);
~ExternalLockSync();
// Create the <src>LockFile</src> object and acquire a read or write
// lock when permanent locking is in effect.
// It throws an exception when acquiring the lock failed.
void makeLock (const String& tableName, Bool create, FileLocker::LockType);
// Acquire a read or write lock (when needed).
// Nattempts==0 indicates that it has to wait until the lock is acquired.
// Nattempts>0 indicates that it gives up acquiring the lock when
// nattempts have been done (with 1 second intervals).
// It throws an exception when acquire failed while it had to wait.
// It returns a false status when acquiring the lock failed
// while it does not have to wait.
// <br>When a lock is successfully acquired, the number of rows
// (see function nrrow() below) is reset as a result of
// synchronizing the access to the table.
Bool acquire (FileLocker::LockType = FileLocker::Write, uInt nattempts = 0);
// Get the current number of rows in this object.
uInt nrow() const;
// Release the lock and synchronize the table access.
// When autolocking is in effect, the lock is only released when
// the inspection-interval (see class
// <linkto class=TableLockData>TableLockData</linkto>) has expired.
// It does nothing when permanent locking is used.
// It throws an exception when the release failed.
void release (uInt nrrow);
// Check if the table has a read or write lock, thus if the table can
// be read or written safely.
Bool hasLock (FileLocker::LockType) const;
private:
// Copy constructor is forbidden.
ExternalLockSync (const ExternalLockSync& that);
// Assignment is forbidden.
ExternalLockSync& operator= (const ExternalLockSync& that);
// The callback function when releasing a lock.
static MemoryIO* releaseCallBack (void* lockSyncObject, Bool always);
// The member function executing the callback functionality.
MemoryIO* doReleaseCallBack (Bool always);
//# Define the lock and sync data objects.
TableLockData itsLock;
TableSyncData itsSync;
uInt itsNrrow;
};
inline Bool ExternalLockSync::hasLock (FileLocker::LockType type) const
{
return itsLock.hasLock (type);
}
inline void ExternalLockSync::release (uInt nrrow)
{
itsNrrow = nrrow;
itsLock.release();
}
inline MemoryIO* ExternalLockSync::doReleaseCallBack (Bool)
{
itsSync.write (itsNrrow);
return &(itsSync.memoryIO());
}
inline uInt ExternalLockSync::nrow() const
{
return itsNrrow;
}
} //# NAMESPACE CASACORE - END
#endif
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