ardour/libs/pbd/undo.cc
Robin Gareus 9e6435ff14
Fix mem-leak, Playlist/Region SessionHandleRef
When a playlist is deleted and drops_references(), any
undo/redo StatefulDiffCommand referncing playlist invoke
Destructible::drop_references() of the Command.

This leads to command_death(). As opposed to UndoTransaction::clear()
the StatefulDiffCommand was not destroyed.

In case of playlists StatefulDiffCommand::_changes contains
PBD::SequenceProperty<std::list<boost::shared_ptr<Region> > >
and shared pointer reference of the playlist regions were kept
indefinitely.

This fixes the following scenario:
New session, import an file, delete the created track,
clean up unused sources (delete unused playlists)[, quit].

A reference to the imported region was kept, because of the
playlist's undo command (insert region). Yet the source file
was deleted.


PS. Most playlist changes are accompanied by GUI zoom/selection
MementoCommands. Those are currently never directly dropped.
command_death() leaves those in place.
2020-02-25 21:45:07 +01:00

373 lines
7.3 KiB
C++

/*
* Copyright (C) 2001 Brett Viren
* Copyright (C) 2001-2015 Paul Davis <paul@linuxaudiosystems.com>
* Copyright (C) 2006 Hans Fugal <hans@fugal.net>
* Copyright (C) 2007-2009 David Robillard <d@drobilla.net>
* Copyright (C) 2012-2017 Tim Mayberry <mojofunk@gmail.com>
* Copyright (C) 2015 Nick Mainsbridge <mainsbridge@gmail.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 <sstream>
#include <string>
#include <time.h>
#include "pbd/undo.h"
#include "pbd/xml++.h"
using namespace std;
using namespace sigc;
UndoTransaction::UndoTransaction ()
: _clearing (false)
{
gettimeofday (&_timestamp, 0);
}
UndoTransaction::UndoTransaction (const UndoTransaction& rhs)
: Command (rhs._name)
, _clearing (false)
{
_timestamp = rhs._timestamp;
clear ();
actions.insert (actions.end (), rhs.actions.begin (), rhs.actions.end ());
}
UndoTransaction::~UndoTransaction ()
{
drop_references ();
clear ();
}
static void
command_death (UndoTransaction* ut, Command* c)
{
if (ut->clearing ()) {
return;
}
ut->remove_command (c);
if (ut->empty ()) {
delete ut;
}
}
UndoTransaction&
UndoTransaction::operator= (const UndoTransaction& rhs)
{
if (this == &rhs) {
return *this;
}
_name = rhs._name;
clear ();
actions.insert (actions.end (), rhs.actions.begin (), rhs.actions.end ());
return *this;
}
void
UndoTransaction::add_command (Command* const cmd)
{
/* catch death of command (e.g. caused by death of object to
* which it refers. command_death() is a normal static function
* so there is no need to manage this connection.
*/
cmd->DropReferences.connect_same_thread (*this, boost::bind (&command_death, this, cmd));
actions.push_back (cmd);
}
void
UndoTransaction::remove_command (Command* const action)
{
list<Command*>::iterator i =std::find (actions.begin (), actions.end (), action);
if (i == actions.end ()) {
return;
}
actions.erase (i);
delete action;
}
bool
UndoTransaction::empty () const
{
return actions.empty ();
}
void
UndoTransaction::clear ()
{
_clearing = true;
for (list<Command*>::iterator i = actions.begin (); i != actions.end (); ++i) {
delete *i;
}
actions.clear ();
_clearing = false;
}
void
UndoTransaction::operator() ()
{
for (list<Command*>::iterator i = actions.begin (); i != actions.end (); ++i) {
(*(*i)) ();
}
}
void
UndoTransaction::undo ()
{
for (list<Command*>::reverse_iterator i = actions.rbegin (); i != actions.rend (); ++i) {
(*i)->undo ();
}
}
void
UndoTransaction::redo ()
{
(*this) ();
}
XMLNode&
UndoTransaction::get_state ()
{
XMLNode* node = new XMLNode ("UndoTransaction");
node->set_property ("tv-sec", (int64_t)_timestamp.tv_sec);
node->set_property ("tv-usec", (int64_t)_timestamp.tv_usec);
node->set_property ("name", _name);
list<Command*>::iterator it;
for (it = actions.begin (); it != actions.end (); it++) {
node->add_child_nocopy ((*it)->get_state ());
}
return *node;
}
class UndoRedoSignaller
{
public:
UndoRedoSignaller (UndoHistory& uh)
: _history (uh)
{
_history.BeginUndoRedo ();
}
~UndoRedoSignaller ()
{
_history.EndUndoRedo ();
}
private:
UndoHistory& _history;
};
UndoHistory::UndoHistory ()
{
_clearing = false;
_depth = 0;
}
void
UndoHistory::set_depth (uint32_t d)
{
uint32_t current_depth = UndoList.size ();
_depth = d;
if (d > current_depth) {
/* not even transactions to meet request */
return;
}
if (_depth > 0) {
uint32_t cnt = current_depth - d;
while (cnt--) {
UndoTransaction* ut = UndoList.front ();
UndoList.pop_front ();
delete ut;
}
}
}
void
UndoHistory::add (UndoTransaction* const ut)
{
uint32_t current_depth = UndoList.size ();
ut->DropReferences.connect_same_thread (*this, boost::bind (&UndoHistory::remove, this, ut));
/* if the current undo history is larger than or equal to the currently
requested depth, then pop off at least 1 element to make space
at the back for new one.
*/
if ((_depth > 0) && current_depth && (current_depth >= _depth)) {
uint32_t cnt = 1 + (current_depth - _depth);
while (cnt--) {
UndoTransaction* ut;
ut = UndoList.front ();
UndoList.pop_front ();
delete ut;
}
}
UndoList.push_back (ut);
/* Adding a transacrion makes the redo list meaningless. */
_clearing = true;
for (std::list<UndoTransaction*>::iterator i = RedoList.begin (); i != RedoList.end (); ++i) {
delete *i;
}
RedoList.clear ();
_clearing = false;
/* we are now owners of the transaction and must delete it when finished with it */
Changed (); /* EMIT SIGNAL */
}
void
UndoHistory::remove (UndoTransaction* const ut)
{
if (_clearing) {
return;
}
UndoList.remove (ut);
RedoList.remove (ut);
Changed (); /* EMIT SIGNAL */
}
/** Undo some transactions.
* @param n Number of transactions to undo.
*/
void
UndoHistory::undo (unsigned int n)
{
if (n == 0) {
return;
}
{
UndoRedoSignaller exception_safe_signaller (*this);
while (n--) {
if (UndoList.size () == 0) {
return;
}
UndoTransaction* ut = UndoList.back ();
UndoList.pop_back ();
ut->undo ();
RedoList.push_back (ut);
}
}
Changed (); /* EMIT SIGNAL */
}
void
UndoHistory::redo (unsigned int n)
{
if (n == 0) {
return;
}
{
UndoRedoSignaller exception_safe_signaller (*this);
while (n--) {
if (RedoList.size () == 0) {
return;
}
UndoTransaction* ut = RedoList.back ();
RedoList.pop_back ();
ut->redo ();
UndoList.push_back (ut);
}
}
Changed (); /* EMIT SIGNAL */
}
void
UndoHistory::clear_redo ()
{
_clearing = true;
for (std::list<UndoTransaction*>::iterator i = RedoList.begin (); i != RedoList.end (); ++i) {
delete *i;
}
RedoList.clear ();
_clearing = false;
Changed (); /* EMIT SIGNAL */
}
void
UndoHistory::clear_undo ()
{
_clearing = true;
for (std::list<UndoTransaction*>::iterator i = UndoList.begin (); i != UndoList.end (); ++i) {
delete *i;
}
UndoList.clear ();
_clearing = false;
Changed (); /* EMIT SIGNAL */
}
void
UndoHistory::clear ()
{
clear_undo ();
clear_redo ();
Changed (); /* EMIT SIGNAL */
}
XMLNode&
UndoHistory::get_state (int32_t depth)
{
XMLNode* node = new XMLNode ("UndoHistory");
if (depth == 0) {
return (*node);
} else if (depth < 0) {
/* everything */
for (list<UndoTransaction*>::iterator it = UndoList.begin (); it != UndoList.end (); ++it) {
node->add_child_nocopy ((*it)->get_state ());
}
} else {
/* just the last "depth" transactions */
list<UndoTransaction*> in_order;
for (list<UndoTransaction*>::reverse_iterator it = UndoList.rbegin (); it != UndoList.rend () && depth; ++it, depth--) {
in_order.push_front (*it);
}
for (list<UndoTransaction*>::iterator it = in_order.begin (); it != in_order.end (); it++) {
node->add_child_nocopy ((*it)->get_state ());
}
}
return *node;
}