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livetrax/session_utils/common.cc
Paul Davis 5d023b4c60 libpbd: fix an important thinko for cross-thread signal architecture
The old code assumed that the thread that created a request buffer for a given
signal-emitting thread would be the latter thread, and thus a thread-local
pointer to the request buffer could be used. This turns out not to be true: the
GUI thread tends to be responsible for constructing the request buffers for
pre-registered threads.

That mechanism has been replaced by using a RWLock protected map using
pthread_t as the key and the request buffer as the value. This allows any
thread to create and register the request buffers used between any other pair
of threads (because the lookup always uses a pthread_t).

The symptoms of this problem were a signal emitted in an audioengine thread
that was propagated to the target thread, but when the target thread scans its
request buffers for requests, it finds nothing (because it didn't know about
the request buffer). In a sense, the signal was successfully delivered to the
target thread, but no meaningful work (i.e the signal handler) is performed.
2023-04-21 12:16:37 -06:00

256 lines
6.1 KiB
C++

/*
* Copyright (C) 2015-2017 Robin Gareus <robin@gareus.org>
*
* 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 <iostream>
#include <cstdlib>
#include <glibmm.h>
#include "pbd/debug.h"
#include "pbd/event_loop.h"
#include "pbd/error.h"
#include "pbd/failed_constructor.h"
#include "pbd/pthread_utils.h"
#include "pbd/receiver.h"
#include "pbd/transmitter.h"
#include "ardour/audioengine.h"
#include "ardour/filename_extensions.h"
#include "ardour/types.h"
#include "common.h"
using namespace std;
using namespace ARDOUR;
using namespace PBD;
static const char* localedir = LOCALEDIR;
class LogReceiver : public Receiver
{
protected:
void receive (Transmitter::Channel chn, const char * str) {
const char *prefix = "";
switch (chn) {
case Transmitter::Debug:
/* ignore */
return;
case Transmitter::Info:
/* ignore */
return;
case Transmitter::Warning:
prefix = ": [WARNING]: ";
break;
case Transmitter::Error:
prefix = ": [ERROR]: ";
break;
case Transmitter::Fatal:
prefix = ": [FATAL]: ";
break;
case Transmitter::Throw:
/* this isn't supposed to happen */
abort ();
}
/* note: iostreams are already thread-safe: no external
lock required.
*/
std::cout << prefix << str << std::endl;
if (chn == Transmitter::Fatal) {
::exit (9);
}
}
};
LogReceiver log_receiver;
/* temporarily required due to some code design confusion (Feb 2014) */
#include "ardour/vst_types.h"
int vstfx_init (void*) { return 0; }
void vstfx_exit () {}
void vstfx_destroy_editor (VSTState*) {}
class MyEventLoop : public sigc::trackable, public EventLoop
{
public:
MyEventLoop (std::string const& name) : EventLoop (name) {
run_loop_thread = Glib::Threads::Thread::self();
}
bool call_slot (InvalidationRecord*, const boost::function<void()>& f) {
if (Glib::Threads::Thread::self() == run_loop_thread) {
f ();
}
return true;
}
Glib::Threads::RWLock& slot_invalidation_rwlock() { return request_buffer_map_lock; }
private:
Glib::Threads::Thread* run_loop_thread;
Glib::Threads::RWLock request_buffer_map_lock;
};
static MyEventLoop *event_loop;
void
SessionUtils::init (bool print_log)
{
if (!ARDOUR::init (true, localedir)) {
cerr << "Ardour failed to initialize\n" << endl;
::exit (EXIT_FAILURE);
}
event_loop = new MyEventLoop ("util");
EventLoop::set_event_loop_for_thread (event_loop);
SessionEvent::create_per_thread_pool ("util", 512);
if (print_log) {
log_receiver.listen_to (warning);
log_receiver.listen_to (error);
log_receiver.listen_to (fatal);
}
}
// TODO return NULL, rather than exit() ?!
static Session * _load_session (string dir, string state)
{
AudioEngine* engine = AudioEngine::create ();
if (!engine->set_backend ("None (Dummy)", "Unit-Test", "")) {
std::cerr << "Cannot create Audio/MIDI engine\n";
::exit (EXIT_FAILURE);
}
engine->set_input_channels (256);
engine->set_output_channels (256);
float sr;
SampleFormat sf;
std::string v;
std::string s = Glib::build_filename (dir, state + statefile_suffix);
if (!Glib::file_test (s, Glib::FILE_TEST_EXISTS | Glib::FILE_TEST_IS_REGULAR)) {
std::cerr << "Cannot read session '"<< s << "'\n";
return 0;
}
if (Session::get_info_from_path (s, sr, sf, v) == 0) {
if (engine->set_sample_rate (sr)) {
std::cerr << "Cannot set session's samplerate.\n";
return 0;
}
} else {
std::cerr << "Cannot get samplerate from session.\n";
return 0;
}
if (engine->start () != 0) {
std::cerr << "Cannot start Audio/MIDI engine\n";
return 0;
}
Session* session = new Session (*engine, dir, state);
engine->set_session (session);
return session;
}
Session *
SessionUtils::load_session (string dir, string state, bool exit_at_failure)
{
Session* s = 0;
try {
s = _load_session (dir, state);
} catch (failed_constructor& e) {
cerr << "failed_constructor: " << e.what() << "\n";
::exit (EXIT_FAILURE);
} catch (AudioEngine::PortRegistrationFailure& e) {
cerr << "PortRegistrationFailure: " << e.what() << "\n";
::exit (EXIT_FAILURE);
} catch (exception& e) {
cerr << "exception: " << e.what() << "\n";
::exit (EXIT_FAILURE);
} catch (...) {
cerr << "unknown exception.\n";
::exit (EXIT_FAILURE);
}
if (!s && exit_at_failure) {
::exit (EXIT_FAILURE);
}
return s;
}
Session *
SessionUtils::create_session (string dir, string state, float sample_rate)
{
AudioEngine* engine = AudioEngine::create ();
if (!engine->set_backend ("None (Dummy)", "Unit-Test", "")) {
std::cerr << "Cannot create Audio/MIDI engine\n";
::exit (EXIT_FAILURE);
}
engine->set_input_channels (256);
engine->set_output_channels (256);
if (engine->set_sample_rate (sample_rate)) {
std::cerr << "Cannot set session's samplerate.\n";
return 0;
}
if (engine->start () != 0) {
std::cerr << "Cannot start Audio/MIDI engine\n";
return 0;
}
std::string s = Glib::build_filename (dir, state + statefile_suffix);
if (Glib::file_test (dir, Glib::FILE_TEST_EXISTS)) {
std::cerr << "Session folder already exists '"<< dir << "'\n";
}
if (Glib::file_test (s, Glib::FILE_TEST_EXISTS)) {
std::cerr << "Session file exists '"<< s << "'\n";
return 0;
}
Session* session = new Session (*engine, dir, state);
engine->set_session (session);
return session;
}
void
SessionUtils::unload_session (Session *s)
{
delete s;
AudioEngine::instance()->stop ();
AudioEngine::destroy ();
}
void
SessionUtils::cleanup ()
{
ARDOUR::cleanup ();
delete event_loop;
pthread_cancel_all ();
}