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/*
*
* 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
* under the License.
*
*/
#include "qpid/sys/AsynchIOHandler.h"
#include "qpid/sys/AsynchIO.h"
#include "qpid/sys/Socket.h"
#include "qpid/framing/AMQP_HighestVersion.h"
#include "qpid/framing/ProtocolInitiation.h"
#include "qpid/log/Statement.h"
#include <boost/bind.hpp>
namespace qpid {
namespace sys {
// Buffer definition
struct Buff : public AsynchIO::BufferBase {
Buff() :
AsynchIO::BufferBase(new char[65536], 65536)
{}
~Buff()
{ delete [] bytes;}
};
AsynchIOHandler::AsynchIOHandler(std::string id, ConnectionCodec::Factory* f) :
identifier(id),
aio(0),
factory(f),
codec(0),
readError(false),
isClient(false),
readCredit(InfiniteCredit)
{}
AsynchIOHandler::~AsynchIOHandler() {
if (codec)
codec->closed();
delete codec;
}
void AsynchIOHandler::init(AsynchIO* a, int numBuffs) {
aio = a;
// Give connection some buffers to use
for (int i = 0; i < numBuffs; i++) {
aio->queueReadBuffer(new Buff);
}
}
void AsynchIOHandler::write(const framing::ProtocolInitiation& data)
{
QPID_LOG(debug, "SENT [" << identifier << "] INIT(" << data << ")");
AsynchIO::BufferBase* buff = aio->getQueuedBuffer();
if (!buff)
buff = new Buff;
framing::Buffer out(buff->bytes, buff->byteCount);
data.encode(out);
buff->dataCount = data.encodedSize();
aio->queueWrite(buff);
}
void AsynchIOHandler::abort() {
// Don't disconnect if we're already disconnecting
if (!readError) {
aio->requestCallback(boost::bind(&AsynchIOHandler::eof, this, _1));
}
}
void AsynchIOHandler::activateOutput() {
aio->notifyPendingWrite();
}
// Input side
void AsynchIOHandler::giveReadCredit(int32_t credit) {
// Check whether we started in the don't about credit state
if (readCredit.boolCompareAndSwap(InfiniteCredit, credit))
return;
// TODO In theory should be able to use an atomic operation before taking the lock
// but in practice there seems to be an unexplained race in that case
ScopedLock<Mutex> l(creditLock);
if (readCredit.fetchAndAdd(credit) != 0)
return;
assert(readCredit.get() >= 0);
if (readCredit.get() != 0)
aio->startReading();
}
void AsynchIOHandler::readbuff(AsynchIO& , AsynchIO::BufferBase* buff) {
if (readError) {
return;
}
// Check here for read credit
if (readCredit.get() != InfiniteCredit) {
if (readCredit.get() == 0) {
// FIXME aconway 2009-10-01: Workaround to avoid "false wakeups".
// readbuff is sometimes called with no credit.
// This should be fixed somewhere else to avoid such calls.
aio->unread(buff);
return;
}
// TODO In theory should be able to use an atomic operation before taking the lock
// but in practice there seems to be an unexplained race in that case
ScopedLock<Mutex> l(creditLock);
if (--readCredit == 0) {
assert(readCredit.get() >= 0);
if (readCredit.get() == 0) {
aio->stopReading();
}
}
}
size_t decoded = 0;
if (codec) { // Already initiated
try {
decoded = codec->decode(buff->bytes+buff->dataStart, buff->dataCount);
}catch(const std::exception& e){
QPID_LOG(error, e.what());
readError = true;
aio->queueWriteClose();
}
}else{
framing::Buffer in(buff->bytes+buff->dataStart, buff->dataCount);
framing::ProtocolInitiation protocolInit;
if (protocolInit.decode(in)) {
decoded = in.getPosition();
QPID_LOG(debug, "RECV [" << identifier << "] INIT(" << protocolInit << ")");
try {
codec = factory->create(protocolInit.getVersion(), *this, identifier);
if (!codec) {
//TODO: may still want to revise this...
//send valid version header & close connection.
write(framing::ProtocolInitiation(framing::highestProtocolVersion));
readError = true;
aio->queueWriteClose();
}
} catch (const std::exception& e) {
QPID_LOG(error, e.what());
readError = true;
aio->queueWriteClose();
}
}
}
// TODO: unreading needs to go away, and when we can cope
// with multiple sub-buffers in the general buffer scheme, it will
if (decoded != size_t(buff->dataCount)) {
// Adjust buffer for used bytes and then "unread them"
buff->dataStart += decoded;
buff->dataCount -= decoded;
aio->unread(buff);
} else {
// Give whole buffer back to aio subsystem
aio->queueReadBuffer(buff);
}
}
void AsynchIOHandler::eof(AsynchIO&) {
QPID_LOG(debug, "DISCONNECTED [" << identifier << "]");
if (codec) codec->closed();
readError = true;
aio->queueWriteClose();
}
void AsynchIOHandler::closedSocket(AsynchIO&, const Socket& s) {
// If we closed with data still to send log a warning
if (!aio->writeQueueEmpty()) {
QPID_LOG(warning, "CLOSING [" << identifier << "] unsent data (probably due to client disconnect)");
}
delete &s;
aio->queueForDeletion();
delete this;
}
void AsynchIOHandler::disconnect(AsynchIO& a) {
// treat the same as eof
eof(a);
}
// Notifications
void AsynchIOHandler::nobuffs(AsynchIO&) {
}
void AsynchIOHandler::idle(AsynchIO&){
if (isClient && codec == 0) {
codec = factory->create(*this, identifier);
write(framing::ProtocolInitiation(codec->getVersion()));
return;
}
if (codec == 0) return;
try {
if (codec->canEncode()) {
// Try and get a queued buffer if not then construct new one
AsynchIO::BufferBase* buff = aio->getQueuedBuffer();
if (!buff) buff = new Buff;
size_t encoded=codec->encode(buff->bytes, buff->byteCount);
buff->dataCount = encoded;
aio->queueWrite(buff);
}
if (codec->isClosed()) {
readError = true;
aio->queueWriteClose();
}
} catch (const std::exception& e) {
QPID_LOG(error, e.what());
readError = true;
aio->queueWriteClose();
}
}
}} // namespace qpid::sys
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