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/* - mode: c; c-basic-offset: 2; indent-tabs-mode: nil; -*-
* vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
*
* Copyright (C) 2010 Brian Aker
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <config.h>
#include <plugin/user_locks/module.h>
#include <boost/thread/locks.hpp>
#include <string>
namespace user_locks {
bool Locks::lock(drizzled::session_id_t id_arg, const user_locks::Key &arg, int64_t wait_for)
{
boost::unique_lock<boost::mutex> scope(mutex);
boost::system_time timeout= boost::get_system_time() + boost::posix_time::seconds(wait_for);
LockMap::iterator iter;
while ((iter= lock_map.find(arg)) != lock_map.end())
{
if (id_arg == iter->second->id)
{
// We own the lock, so we just exit.
return true;
}
try {
if (wait_for)
{
bool success= release_cond.timed_wait(scope, timeout);
if (not success)
return false;
}
else
{
release_cond.wait(scope);
}
}
catch(boost::thread_interrupted const& error)
{
// Currently nothing is done here.
throw error;
}
}
if (iter == lock_map.end())
{
create_cond.notify_all();
return lock_map.insert(std::make_pair(arg, new Lock(id_arg))).second;
}
return false;
}
// Currently we just let timeouts occur, and the caller will need to know
// what it is looking for/whether to go back into this.
void Locks::waitCreate(int64_t wait_for)
{
boost::unique_lock<boost::mutex> scope(mutex);
boost::system_time timeout= boost::get_system_time() + boost::posix_time::seconds(wait_for);
try {
create_cond.timed_wait(scope, timeout);
}
catch(boost::thread_interrupted const& error)
{
// Currently nothing is done here.
throw error;
}
}
bool Locks::lock(drizzled::session_id_t id_arg, const user_locks::Keys &arg)
{
boost::unique_lock<boost::mutex> scope(mutex);
user_locks::Keys created;
bool error= false;
for (user_locks::Keys::const_iterator iter= arg.begin(); iter != arg.end(); iter++)
{
LockMap::iterator record= lock_map.find(*iter);
if (record != lock_map.end()) // Found, so check ownership of the lock
{
if (id_arg != (*record).second->id)
{
// So it turns out the locks exist, and we can't grab them all
error= true;
break;
}
}
else
{
lock_map.insert(std::make_pair(*iter, new Lock(id_arg)));
created.insert(*iter);
}
}
if (error)
{
for (user_locks::Keys::const_iterator iter= created.begin(); iter != created.end(); iter++)
{
lock_map.erase(*iter);
}
return false;
}
create_cond.notify_all();
return true;
}
bool Locks::isUsed(const user_locks::Key &arg, drizzled::session_id_t &id_arg)
{
boost::unique_lock<boost::mutex> scope(mutex);
LockMap::iterator iter= lock_map.find(arg);
if ( iter == lock_map.end())
return false;
id_arg= iter->second->id;
return true;
}
bool Locks::isFree(const user_locks::Key &arg)
{
boost::unique_lock<boost::mutex> scope(mutex);
LockMap::iterator iter= lock_map.find(arg);
return iter != lock_map.end();
}
void Locks::Copy(LockMap &lock_map_arg)
{
boost::unique_lock<boost::mutex> scope(mutex);
lock_map_arg= lock_map;
}
locks::return_t Locks::release(const user_locks::Key &arg, drizzled::session_id_t &id_arg, bool and_wait)
{
size_t elements= 0;
boost::unique_lock<boost::mutex> scope(mutex);
LockMap::iterator iter= lock_map.find(arg);
// Nothing is found
if ( iter == lock_map.end())
return locks::NOT_FOUND;
if (iter->second->id == id_arg)
{
elements= lock_map.erase(arg);
assert(elements); // If we can't find what we just found, then we are broken
if (elements)
{
release_cond.notify_one();
if (and_wait)
{
bool found= false;
while (not found)
{
assert(boost::this_thread::interruption_enabled());
try {
create_cond.wait(scope);
}
catch(boost::thread_interrupted const& error)
{
// Currently nothing is done here.
throw error;
}
iter= lock_map.find(arg);
if (iter != lock_map.end())
found= true;
}
}
return locks::SUCCESS;
}
}
return locks::NOT_OWNED_BY;
}
} /* namespace user_locks */
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