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Viewing changes to src/common/dispatch/action_queue.cpp

  • Committer: Daniel van Vugt
  • Date: 2015-04-28 07:54:10 UTC
  • mfrom: (2517 development-branch)
  • mto: This revision was merged to the branch mainline in revision 2673.
  • Revision ID: daniel.van.vugt@canonical.com-20150428075410-rwskshfuar7voesp
Merge latest trunk and fix conflicts.

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src/common/dispatch/action_queue.cpp
 
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/*
 
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 * Copyright © 2015 Canonical Ltd.
 
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 *
 
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 * This program is free software: you can redistribute it and/or modify it
 
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 * under the terms of the GNU Lesser General Public License version 3,
 
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 * as published by the Free Software Foundation.
 
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 *
 
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 * This program is distributed in the hope that it will be useful,
 
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 
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 * GNU Lesser General Public License for more details.
 
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 *
 
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 * You should have received a copy of the GNU Lesser General Public License
 
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 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
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 *
 
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 * Authored by: Andreas Pokorny <andreas.pokorny@canonical.com>
 
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 */
 
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#include "mir/dispatch/action_queue.h"
 
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#include <boost/throw_exception.hpp>
 
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#include <sys/eventfd.h>
 
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mir::dispatch::ActionQueue::ActionQueue()
 
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    : event_fd{eventfd(0, EFD_CLOEXEC|EFD_NONBLOCK)}
 
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{
 
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    if (event_fd < 0)
 
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        BOOST_THROW_EXCEPTION((std::system_error{errno,
 
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                                                 std::system_category(),
 
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                                                 "Failed to create event fd for action queue"}));
 
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}
 
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mir::Fd mir::dispatch::ActionQueue::watch_fd() const
 
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{
 
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    return event_fd;
 
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}
 
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void mir::dispatch::ActionQueue::enqueue(std::function<void()> const& action)
 
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{
 
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    std::unique_lock<std::mutex> lock(list_lock);
 
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    actions.push_back(action);
 
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    wake();
 
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}
 
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bool mir::dispatch::ActionQueue::dispatch(FdEvents events)
 
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{
 
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    if (events&FdEvent::error)
 
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        return false;
 
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    std::list<std::function<void()>> actions_to_process;
 
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    {
 
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        std::unique_lock<std::mutex> lock(list_lock);
 
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        consume();
 
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        std::swap(actions_to_process, actions);
 
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    }
 
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    while(!actions_to_process.empty())
 
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    {
 
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        actions_to_process.front()();
 
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        actions_to_process.pop_front();
 
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    }
 
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    return true;
 
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}
 
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mir::dispatch::FdEvents mir::dispatch::ActionQueue::relevant_events() const
 
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{
 
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    return FdEvent::readable;
 
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}
 
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void mir::dispatch::ActionQueue::consume()
 
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{
 
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    uint64_t num_actions;
 
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    if (read(event_fd, &num_actions, sizeof num_actions) != sizeof num_actions)
 
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        BOOST_THROW_EXCEPTION((std::system_error{errno,
 
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                                                 std::system_category(),
 
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                                                 "Failed to consume action queue notification"}));
 
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}
 
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void mir::dispatch::ActionQueue::wake()
 
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{
 
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    uint64_t one_more{1};
 
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    if (write(event_fd, &one_more, sizeof one_more) != sizeof one_more)
 
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        BOOST_THROW_EXCEPTION((std::system_error{errno,
 
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                                                 std::system_category(),
 
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                                                 "Failed to wake action queue"}));
 
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}