office-gobmx/ucb/source/ucp/webdav-curl/SerfLockStore.cxx
Michael Stahl 7ac06bdbf8 ucb: webdav-curl: fix deadlock in SerfLockStore::refreshLocks()
... and removeLock()

(regression from commit 03c7cd9bbe)

Change-Id: I4029a7079c7331a7a00c11e2bec5639086bcc928
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/129666
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>
Reviewed-by: Michael Stahl <michael.stahl@allotropia.de>
Tested-by: Jenkins
2022-02-08 16:02:30 +01:00

256 lines
7 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
* This file is part of the LibreOffice project.
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*
* This file incorporates work covered by the following license notice:
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed
* with this work for additional information regarding copyright
* ownership. The ASF licenses this file to you under the Apache
* License, Version 2.0 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.apache.org/licenses/LICENSE-2.0 .
*/
#include <rtl/ustring.hxx>
#include <sal/log.hxx>
#include <osl/time.h>
#include <osl/thread.hxx>
#include <salhelper/thread.hxx>
#include <com/sun/star/ucb/LockScope.hpp>
#include "CurlSession.hxx"
#include "SerfLockStore.hxx"
using namespace http_dav_ucp;
namespace http_dav_ucp {
class TickerThread : public salhelper::Thread
{
bool m_bFinish;
SerfLockStore & m_rLockStore;
public:
explicit TickerThread( SerfLockStore & rLockStore )
: Thread( "WebDavTickerThread" ), m_bFinish( false ),
m_rLockStore( rLockStore ) {}
void finish() { m_bFinish = true; }
private:
virtual void execute();
};
} // namespace http_dav_ucp
void TickerThread::execute()
{
osl_setThreadName("http_dav_ucp::TickerThread");
SAL_INFO("ucb.ucp.webdav", "TickerThread: start." );
// we have to go through the loop more often to be able to finish ~quickly
const int nNth = 25;
int nCount = nNth;
while ( !m_bFinish )
{
if ( nCount-- <= 0 )
{
m_rLockStore.refreshLocks();
nCount = nNth;
}
TimeValue aTV;
aTV.Seconds = 0;
aTV.Nanosec = 1000000000 / nNth;
salhelper::Thread::wait( aTV );
}
SAL_INFO("ucb.ucp.webdav", "TickerThread: stop." );
}
SerfLockStore::SerfLockStore()
{
}
SerfLockStore::~SerfLockStore()
{
std::unique_lock aGuard(m_aMutex);
stopTicker(aGuard);
aGuard.lock(); // actually no threads should even try to access members now
// release active locks, if any.
SAL_WARN_IF( !m_aLockInfoMap.empty(), "ucb.ucp.webdav",
"SerfLockStore::~SerfLockStore - Releasing active locks!" );
for ( auto& rLockInfo : m_aLockInfoMap )
{
rLockInfo.second.m_xSession->NonInteractive_UNLOCK(rLockInfo.first);
}
}
void SerfLockStore::startTicker()
{
std::unique_lock aGuard( m_aMutex );
if ( !m_pTickerThread.is() )
{
m_pTickerThread = new TickerThread( *this );
m_pTickerThread->launch();
}
}
void SerfLockStore::stopTicker(std::unique_lock<std::mutex> & rGuard)
{
rtl::Reference<TickerThread> pTickerThread;
if (m_pTickerThread.is())
{
m_pTickerThread->finish(); // needs mutex
// the TickerThread may run refreshLocks() at most once after this
pTickerThread = m_pTickerThread;
m_pTickerThread.clear();
}
rGuard.unlock();
if (pTickerThread.is() && pTickerThread->getIdentifier() != osl::Thread::getCurrentIdentifier())
{
pTickerThread->join(); // without m_aMutex locked (to prevent deadlock)
}
}
OUString const*
SerfLockStore::getLockTokenForURI(OUString const& rURI, css::ucb::Lock const*const pLock)
{
assert(rURI.startsWith("http://") || rURI.startsWith("https://"));
std::unique_lock aGuard( m_aMutex );
auto const it(m_aLockInfoMap.find(rURI));
if (it == m_aLockInfoMap.end())
{
return nullptr;
}
if (!pLock) // any lock will do
{
return &it->second.m_sToken;
}
// 0: EXCLUSIVE 1: SHARED
if (it->second.m_Lock.Scope == ucb::LockScope_SHARED && pLock->Scope == ucb::LockScope_EXCLUSIVE)
{
return nullptr;
}
assert(it->second.m_Lock.Type == pLock->Type); // only WRITE possible
if (it->second.m_Lock.Depth < pLock->Depth)
{
return nullptr;
}
// Only own locks are expected in the lock store, but depending on the
// server it->second.m_Lock.Owner may contain the string this UCP passed in
// the LOCK request, or a user identifier generated by the server (happens
// with Sharepoint), so just ignore it here.
// ignore Timeout ?
return &it->second.m_sToken;
}
void SerfLockStore::addLock( const OUString& rURI,
ucb::Lock const& rLock,
const OUString& sToken,
rtl::Reference<CurlSession> const & xSession,
sal_Int32 nLastChanceToSendRefreshRequest )
{
assert(rURI.startsWith("http://") || rURI.startsWith("https://"));
{
std::unique_lock aGuard( m_aMutex );
m_aLockInfoMap[ rURI ]
= LockInfo(sToken, rLock, xSession, nLastChanceToSendRefreshRequest);
}
startTicker();
}
void SerfLockStore::removeLock(const OUString& rURI)
{
std::unique_lock aGuard( m_aMutex );
removeLockImpl(aGuard, rURI);
}
void SerfLockStore::removeLockImpl(std::unique_lock<std::mutex> & rGuard, const OUString& rURI)
{
assert(rURI.startsWith("http://") || rURI.startsWith("https://"));
m_aLockInfoMap.erase(rURI);
if ( m_aLockInfoMap.empty() )
{
stopTicker(rGuard);
}
}
void SerfLockStore::refreshLocks()
{
std::unique_lock aGuard( m_aMutex );
::std::vector<OUString> authFailedLocks;
for ( auto& rLockInfo : m_aLockInfoMap )
{
LockInfo & rInfo = rLockInfo.second;
if ( rInfo.m_nLastChanceToSendRefreshRequest != -1 )
{
// 30 seconds or less remaining until lock expires?
TimeValue t1;
osl_getSystemTime( &t1 );
if ( rInfo.m_nLastChanceToSendRefreshRequest - 30
<= sal_Int32( t1.Seconds ) )
{
// refresh the lock.
sal_Int32 nlastChanceToSendRefreshRequest = -1;
bool isAuthFailed(false);
if (rInfo.m_xSession->NonInteractive_LOCK(
rLockInfo.first, rLockInfo.second.m_sToken,
nlastChanceToSendRefreshRequest,
isAuthFailed))
{
rInfo.m_nLastChanceToSendRefreshRequest
= nlastChanceToSendRefreshRequest;
}
else
{
if (isAuthFailed)
{
authFailedLocks.push_back(rLockInfo.first);
}
// refresh failed. stop auto-refresh.
rInfo.m_nLastChanceToSendRefreshRequest = -1;
}
}
}
}
for (auto const& rLock : authFailedLocks)
{
removeLockImpl(aGuard, rLock);
}
}
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */