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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/AsynchIO.h"
#include "check.h"
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <errno.h>
#include <boost/bind.hpp>
using namespace qpid::sys;
namespace {
/*
* Make file descriptor non-blocking
*/
void nonblocking(int fd) {
QPID_POSIX_CHECK(::fcntl(fd, F_SETFL, O_NONBLOCK));
}
}
/*
* Asynch Acceptor
*/
AsynchAcceptor::AsynchAcceptor(int fd, Callback callback) :
acceptedCallback(callback),
handle(fd, boost::bind(&AsynchAcceptor::readable, this, _1), 0) {
nonblocking(fd);
}
void AsynchAcceptor::start(Poller::shared_ptr poller) {
handle.watch(poller);
}
/*
* We keep on accepting as long as there is something to accept
*/
void AsynchAcceptor::readable(DispatchHandle& h) {
int afd;
do {
errno = 0;
// TODO: Currently we ignore the peers address, perhaps we should
// log it or use it for connection acceptance.
afd = ::accept(h.getFD(), 0, 0);
if (afd >= 0) {
acceptedCallback(afd);
} else if (errno == EAGAIN) {
break;
} else {
QPID_POSIX_CHECK(afd);
}
} while (true);
h.rewatch();
}
/*
* Asynch reader/writer
*/
AsynchIO::AsynchIO(int fd, ReadCallback rCb, EofCallback eofCb, BuffersEmptyCallback eCb, IdleCallback iCb) :
readCallback(rCb),
eofCallback(eofCb),
emptyCallback(eCb),
idleCallback(iCb),
handle(fd, boost::bind(&AsynchIO::readable, this, _1), boost::bind(&AsynchIO::writeable, this, _1)) {
nonblocking(fd);
}
void AsynchIO::start(Poller::shared_ptr poller) {
handle.watch(poller);
}
void AsynchIO::QueueReadBuffer(const Buffer& buff) {
bufferQueue.push_front(buff);
handle.rewatchRead();
}
void AsynchIO::QueueWrite(const Buffer& buff) {
writeQueue.push_front(buff);
handle.rewatchWrite();
}
/*
* We keep on reading as long as we have something to read and a buffer to put
* it in
*/
void AsynchIO::readable(DispatchHandle& h) {
do {
// (Try to) get a buffer
if (!bufferQueue.empty()) {
// Read into buffer
Buffer buff = bufferQueue.back();
bufferQueue.pop_back();
errno = 0;
int rc = ::read(h.getFD(), buff.bytes, buff.byteCount);
if (rc == 0) {
eofCallback();
} else if (rc > 0) {
readCallback(buff, rc);
} else {
// Put buffer back
bufferQueue.push_back(buff);
if (errno == EAGAIN) {
// We must have just put a buffer back so we know
// we can do this
h.rewatchRead();
return;
} else {
QPID_POSIX_CHECK(rc);
}
}
} else {
// Something to read but no buffer
if (emptyCallback) {
emptyCallback();
}
// If we still have no buffers we can't do anything more
if (bufferQueue.empty()) {
return;
}
}
} while (true);
}
/*
* We carry on writing whilst we have data to write and we can write
*/
void AsynchIO::writeable(DispatchHandle& h) {
do {
// See if we've got something to write
if (!writeQueue.empty()) {
// Write buffer
Buffer buff = writeQueue.back();
writeQueue.pop_back();
errno = 0;
int rc = ::write(h.getFD(), buff.bytes, buff.byteCount);
if (rc >= 0) {
// Recycle the buffer
QueueReadBuffer(buff);
} else {
// Put buffer back
writeQueue.push_back(buff);
if (errno == EAGAIN) {
// We have just put a buffer back so we know
// we can do this
h.rewatchWrite();
return;
} else {
QPID_POSIX_CHECK(rc);
}
}
} else {
// Something to read but no buffer
if (idleCallback) {
idleCallback(h.getFD());
}
// If we still have no buffers to write we can't do anything more
if (writeQueue.empty()) {
return;
}
}
} while (true);
}
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