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XrdSysXSLock.hh
Go to the documentation of this file.
#ifndef __SYS_XSLOCK_HH__
#define __SYS_XSLOCK_HH__
/******************************************************************************/
/* */
/* X r d S y s X S L o c k . h h */
/* */
/* (c) 2003 by the Board of Trustees of the Leland Stanford, Jr., University */
/* All Rights Reserved */
/* Produced by Andrew Hanushevsky for Stanford University under contract */
/* DE-AC02-76-SFO0515 with the Department of Energy */
/* */
/* This file is part of the XRootD software suite. */
/* */
/* XRootD is free software: you can redistribute it and/or modify it under */
/* the terms of the GNU Lesser General Public License as published by the */
/* Free Software Foundation, either version 3 of the License, or (at your */
/* option) any later version. */
/* */
/* XRootD 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 Lesser General Public */
/* License for more details. */
/* */
/* You should have received a copy of the GNU Lesser General Public License */
/* along with XRootD in a file called COPYING.LESSER (LGPL license) and file */
/* COPYING (GPL license). If not, see <http://www.gnu.org/licenses/>. */
/* */
/* The copyright holder's institutional names and contributor's names may not */
/* be used to endorse or promote products derived from this software without */
/* specific prior written permission of the institution or contributor. */
/******************************************************************************/
#include <cerrno>
#include "XrdSys/XrdSysPthread.hh"
// These are valid usage options
//
enum XrdSysXS_Type {xs_None = 0, xs_Shared = 1, xs_Exclusive = 2};
// This class implements the shared lock. Any number of readers are allowed
// by requesting a shared lock. Only one exclusive writer is allowed by
// requesting an exclusive lock. Up/downgrading is not supported.
//
class XrdSysXSLock
{
public:
void Lock(const XrdSysXS_Type usage);
void UnLock(const XrdSysXS_Type usage=xs_None);
XrdSysXSLock() : cur_usage(xs_None), cur_count(0), exc_wait(0),
shr_wait(0), toggle(0), WantShr(0), WantExc(0) {}
~XrdSysXSLock();
private:
XrdSysXS_Type cur_usage;
int cur_count;
int exc_wait;
int shr_wait;
int toggle;
XrdSysMutex LockContext;
XrdSysSemaphore WantShr;
XrdSysSemaphore WantExc;
};
#endif
usage
void usage()
Definition XrdClReplay.cc:1072
XrdSysPthread.hh
XrdSysXS_Type
XrdSysXS_Type
Definition XrdSysXSLock.hh:38
xs_Exclusive
@ xs_Exclusive
Definition XrdSysXSLock.hh:38
xs_None
@ xs_None
Definition XrdSysXSLock.hh:38
xs_Shared
@ xs_Shared
Definition XrdSysXSLock.hh:38
XrdSysMutex
Definition XrdSysPthread.hh:165
XrdSysSemaphore
Definition XrdSysPthread.hh:494
XrdSysXSLock::Lock
void Lock(const XrdSysXS_Type usage)
Definition XrdSysXSLock.cc:55
XrdSysXSLock::UnLock
void UnLock(const XrdSysXS_Type usage=xs_None)
Definition XrdSysXSLock.cc:95
XrdSysXSLock::XrdSysXSLock
XrdSysXSLock()
Definition XrdSysXSLock.hh:52
XrdSysXSLock::~XrdSysXSLock
~XrdSysXSLock()
Definition XrdSysXSLock.cc:38