file_lock_table.cc

// Copyright (c) 2016, Robert Escriva
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
//     * Redistributions of source code must retain the above copyright notice,
//       this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above copyright
//       notice, this list of conditions and the following disclaimer in the
//       documentation and/or other materials provided with the distribution.
//     * Neither the name of this project nor the names of its contributors may
//       be used to endorse or promote products derived from this software
//       without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.

// e
#include "file_lock_table.h"

using e::file_lock_table;

static file_lock_table _neo;

file_lock_table*
file_lock_table :: the_one_and_only()
{
    return &_neo;
}

file_lock_table :: file_lock_table()
    : m_mtx()
    , m_files()
{
}

file_lock_table :: ~file_lock_table() throw ()
{
}

bool
file_lock_table :: acquire(dev_t dev, ino_t ino)
{
    po6::threads::mutex::hold hold(&m_mtx);
    file_t key(dev, ino);
    std::pair<file_map_t::iterator, bool> x = m_files.insert(key);
    return x.second;
}

void
file_lock_table :: release(dev_t dev, ino_t ino)
{
    po6::threads::mutex::hold hold(&m_mtx);
    file_t key(dev, ino);
    file_map_t::iterator it = m_files.find(key);

    if (it != m_files.end())
    {
        m_files.erase(it);
    }
}