Poller.ct

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//
// Copyright (c) 2020 Fraunhofer Institute for Applied Information Technology (FIT)
//                    Network Research Group (NET)
//                    Schloss Birlinghoven, 53754 Sankt Augustin, GERMANY
//                    Contact: support@wiback.org
//
// This file is part of the SENF code tree.
// It is licensed under the 3-clause BSD License (aka New BSD License).
// See LICENSE.txt in the top level directory for details or visit
// https://opensource.org/licenses/BSD-3-Clause
//


/** \file
    \brief Poller non-inline template implementation  */

//#include "Poller.ih"

// Custom includes
#include <errno.h>
#include <senf/Utils/Exception.hh>
#include <senf/Utils/senflikely.hh>

#define prefix_
//-/////////////////////////////////////////////////////////////////////////////////////////////////

template <class Value>
prefix_ bool senf::scheduler::detail::Poller<Value>::set(int fd, int events, Value * data)
{
    struct epoll_event ev = { uint32_t(events), { data } };
    if (epoll_ctl(epollFd_, EPOLL_CTL_ADD, fd, &ev) != -1)
        return true;
    if (errno == EEXIST)
        if (epoll_ctl(epollFd_, EPOLL_CTL_MOD, fd, &ev) != -1)
            return true;
    if (errno == EPERM)
        return false;
    SENF_THROW_SYSTEM_EXCEPTION("epolll_ctl()");
}

template <class Value>
prefix_ void senf::scheduler::detail::Poller<Value>::remove(int fd)
{
    if (epoll_ctl(epollFd_, EPOLL_CTL_DEL, fd, 0) == -1)
        if (errno != ENOENT && errno != EBADF && errno != EPERM)
            // Calling remove() on a file descriptor which is not registered
            // is no error, it shall be ignored:
            // ENOENT: Not part of the poller but a valid (open) fd
            // EBADF: The fd has been closed already. The kernel automatically removes such fds
            //     from epoll structures
            // EPERM: The fd does not support epoll and thus can never have been added
            SENF_THROW_SYSTEM_EXCEPTION("epoll_ctl()");
}

template <class Value>
prefix_ typename senf::scheduler::detail::Poller<Value>::range senf::scheduler::detail::Poller<Value>::wait()
{
    static epoll_event events[NumEvents];
    int rv (epoll_wait(epollFd_, events, NumEvents, timeout_));
    if (SENF_UNLIKELY(rv == -1)) {
        if (errno == EINTR)
            rv = 0;
        else
            SENF_THROW_SYSTEM_EXCEPTION("epoll_wait()");
    }
    return boost::make_iterator_range(
        boost::make_transform_iterator(events, GetPollResult()),
        boost::make_transform_iterator(events+rv, GetPollResult()) );
}

//-/////////////////////////////////////////////////////////////////////////////////////////////////
#undef prefix_


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// c-file-style: "senf"
// indent-tabs-mode: nil
// ispell-local-dictionary: "american"
// compile-command: "scons -u test"
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