annotate base/Serialiser.cpp @ 1376:d9511f9e04d7 dev/refactor-piper-related

Introduce some POD structs for describing an external server application and the desired libraries to load from it, and disambiguating between empty list request and invalid list request. This allows for overriding PiperVampPluginFactory behaviour for using a PluginScan to populate the list request.

/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */

/*
    Sonic Visualiser
    An audio file viewer and annotation editor.
    Centre for Digital Music, Queen Mary, University of London.
    This file copyright 2007 QMUL.
    
    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public License as
    published by the Free Software Foundation; either version 2 of the
    License, or (at your option) any later version.  See the file
    COPYING included with this distribution for more information.
*/

#include "Serialiser.h"

#include <iostream>

QMutex
Serialiser::m_mapMutex;

std::map<QString, QMutex *>
Serialiser::m_mutexMap;

Serialiser::Serialiser(QString id) :
    m_id(id)
{
    m_mapMutex.lock();
    
    if (m_mutexMap.find(m_id) == m_mutexMap.end()) {
        m_mutexMap[m_id] = new QMutex;
    }

    // The id mutexes are never deleted, so once we have a reference
    // to the one we need, we can hold on to it while we release the
    // map mutex.  We need to release the map mutex, otherwise if the
    // id mutex is currently held, it will never be released (because
    // the destructor needs to hold the map mutex to release the id
    // mutex).

    QMutex *idMutex = m_mutexMap[m_id];

    m_mapMutex.unlock();

    idMutex->lock();
}

Serialiser::~Serialiser()
{
    m_mapMutex.lock();
    
    m_mutexMap[m_id]->unlock();

    m_mapMutex.unlock();
}