On 03/14/2011 02:12 PM, Carl Trieloff wrote:
On 03/14/2011 10:07 AM, Gordon Sim wrote:
Its the iterator that is the issue, not the smart pointer that it
points to. You test (it == bindingCache.end()) outside the lock and
that is not safe.
FYI -- .end() function is independent of the validity of the iterator.
'it' will either == the const of end, or ref the smart pointer which
is then safe, even if cleared. I maintain it it safe.
I maintain it is not and offer the attached test as evidence of that.
This reliably crashes the broker after your change but not when that
change is reverted.
/*
*
* 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
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
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#include <qpid/client/Connection.h>
#include <qpid/client/AsyncSession.h>
#include <qpid/client/Session.h>
#include <qpid/sys/Runnable.h>
#include <qpid/sys/Thread.h>
#include <boost/bind.hpp>
#include <boost/format.hpp>
#include <boost/lexical_cast.hpp>
#include <boost/ptr_container/ptr_vector.hpp>
#include <iostream>
#include <vector>
using namespace qpid::client;
using namespace qpid::sys;
class Client : public Runnable
{
Thread thread;
bool failed;
void run()
{
try {
execute();
} catch(const std::exception& error) {
std::cout << error.what() << std::endl;
failed = true;
}
}
protected:
virtual void execute() = 0;
public:
Client () : failed(false) {}
virtual ~Client() {}
void start()
{
thread = Thread(*this);
}
void wait()
{
thread.join();
}
};
typedef std::vector<std::string> Strings;
class Binder : public Client
{
const ConnectionSettings settings;
const std::string exchange;
const Strings queues;
const Strings keys;
void execute()
{
Connection connection;
connection.open(settings);
Session session = connection.newSession();
while (true) {
for (Strings::const_iterator q = queues.begin(); q != queues.end(); q++) {
session.queueDeclare(arg::queue=*q);
for (Strings::const_iterator i = keys.begin(); i != keys.end(); i++) {
session.exchangeBind(arg::exchange=exchange, arg::queue=*q, arg::bindingKey=*i);
}
}
for (Strings::const_iterator q = queues.begin(); q != queues.end(); q++) {
for (Strings::const_iterator i = keys.begin(); i != keys.end(); i++) {
session.exchangeUnbind(arg::exchange=exchange, arg::queue=*q, arg::bindingKey=*i);
}
session.queueDelete(arg::queue=*q);
}
}
}
public:
Binder(const ConnectionSettings& s, const std::string& e, const Strings& q, const Strings& k) :
settings(s), exchange(e), queues(q), keys(k) {}
};
class Checker : public Client
{
const ConnectionSettings settings;
const std::string exchange;
const Strings queues;
const Strings keys;
void checkKeysForQueue(Session& session, const std::string& q)
{
if (keys.empty()) {
session.exchangeBound(arg::exchange=exchange, arg::queue=q);
} else {
for (Strings::const_iterator k = keys.begin(); k != keys.end(); k++) {
session.exchangeBound(arg::exchange=exchange, arg::queue=q, arg::bindingKey=*k);
}
}
}
void execute()
{
Connection connection;
connection.open(settings);
Session session = connection.newSession();
while (true) {
if (queues.empty()) {
checkKeysForQueue(session, "");
} else {
for (Strings::const_iterator q = queues.begin(); q != queues.end(); q++) {
session.queueDeclare(arg::queue=*q);
checkKeysForQueue(session, *q);
}
}
}
}
public:
Checker(const ConnectionSettings& s, const std::string& e, const Strings& q, const Strings& k) :
settings(s), exchange(e), queues(q), keys(k) {}
};
class Sender : public Client
{
const ConnectionSettings settings;
const std::string exchange;
const Strings keys;
void execute()
{
Connection connection;
connection.open(settings);
AsyncSession session = connection.newSession();
Message message;
while (true) {
for (Strings::const_iterator k = keys.begin(); k != keys.end(); k++) {
message.getDeliveryProperties().setRoutingKey(*k);
session.messageTransfer(arg::destination=exchange, arg::content=message);
}
}
}
public:
Sender(const ConnectionSettings& s, const std::string& e, const Strings& k) :
settings(s), exchange(e), keys(k) {}
};
typedef boost::ptr_vector<Client> Clients;
std::string getString(const std::string& base, uint i)
{
return boost::lexical_cast<std::string>(boost::format("%1%:%2%") % base % i);
}
Strings getStrings(const std::string& base, uint count)
{
Strings strings;
for (uint i = 0; i < count; i++) {
strings.push_back(getString(base, i));
}
return strings;
}
int main(int argc, char** argv) {
try {
std::string exchange = "amq.topic";
ConnectionSettings settings;
if (argc > 1) settings.host = argv[1];
if (argc > 2) settings.port = atoi(argv[2]);
if (argc > 3) exchange = argv[3];
Clients clients;
clients.push_back(new Checker(settings, exchange, getStrings("dummy", 1), Strings()));
for (uint i = 0; i < 10; i++) {
clients.push_back(new Binder(settings, exchange, getStrings((boost::format("queue%1%") % i).str(), 1000), getStrings("k", 1000)));
clients.push_back(new Sender(settings, exchange, getStrings("k", 1000)));
}
std::for_each(clients.begin(), clients.end(), boost::bind(&Client::start, _1));
std::for_each(clients.begin(), clients.end(), boost::bind(&Client::wait, _1));
return 0;
} catch(const std::exception& error) {
std::cout << error.what() << std::endl;
}
return 1;
}
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