Files
ardour/libs/ardour/session_handle.cc

145 lines
3.7 KiB
C++

/*
* Copyright (C) 2009-2016 Paul Davis <paul@linuxaudiosystems.com>
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "pbd/demangle.h"
#include "pbd/error.h"
#include "ardour/boost_debug.h"
#include "ardour/session.h"
#include "ardour/session_handle.h"
#ifdef TRACE_SETSESSION_NULL
#include <cassert>
#include "pbd/stacktrace.h"
#endif
#include "pbd/i18n.h"
using namespace std;
using namespace ARDOUR;
using namespace PBD;
SessionHandlePtr::SessionHandlePtr ()
: _session (0)
#ifdef TRACE_SETSESSION_NULL
, _gone_away_emitted (false)
#endif
{
}
SessionHandlePtr::SessionHandlePtr (Session* s)
: _session (s)
#ifdef TRACE_SETSESSION_NULL
, _gone_away_emitted (false)
#endif
{
if (_session) {
_session->DropReferences.connect_same_thread (_session_connections, std::bind (&SessionHandlePtr::session_going_away, this));
}
}
void
SessionHandlePtr::set_session (Session* s)
{
_session_connections.drop_connections ();
#ifdef TRACE_SETSESSION_NULL
/* DropReferences may already have been disconnected due to signal emission ordering.
*
* An instance of this class (e.g. Ardour_UI) will need to call ::set_session() on member instances.
*
* Yet, when session_going_away() first calls set_session (0) on an instance that has SessionHandlePtr members,
* they will reach here, and disocnnect signal handlers. Their derived implementation of ::session_going_away()
* will not be called.
*/
if (!_gone_away_emitted && _session && !s) {
/* if this assert goes off, some ::set_session() implementation calls
* some_member->set_session (0);
*
* replace it with
*
* if (session) {
* some_member->set_session (session);
* }
*/
PBD::stacktrace (cerr, 10);
assert (0);
_gone_away_emitted = true;
session_going_away ();
}
#endif
if (_session) {
_session = 0;
}
if (s) {
_session = s;
_session->DropReferences.connect_same_thread (_session_connections, std::bind (&SessionHandlePtr::session_going_away, this));
#ifdef TRACE_SETSESSION_NULL
_gone_away_emitted = false;
#endif
}
}
void
SessionHandlePtr::session_going_away ()
{
#ifdef TRACE_SETSESSION_NULL
if (_session && !_gone_away_emitted) {
_gone_away_emitted = true;
set_session (0);
}
#else
set_session (0);
#endif
}
/*-------------------------*/
SessionHandleRef::SessionHandleRef (Session& s)
: _session (s)
{
_session.DropReferences.connect_same_thread (*this, std::bind (&SessionHandleRef::session_going_away, this));
_session.Destroyed.connect_same_thread (*this, std::bind (&SessionHandleRef::insanity_check, this));
}
SessionHandleRef::~SessionHandleRef ()
{
}
void
SessionHandleRef::session_going_away ()
{
/* a handleRef is allowed to exist at the time of DropReferences, but not at the time of Destroyed
*/
}
void
SessionHandleRef::insanity_check ()
{
#ifndef NDEBUG
cerr << string_compose (
_("programming error: %1"),
string_compose("SessionHandleRef exists across session deletion! Dynamic type: %1 @ %2",
PBD::demangled_name (*this), this))
<< endl;
#endif
}