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livetrax/libs/ardour/worker.cc
Robin Gareus 7258c6334d Namespace PBD::RingBuffer
class RingBuffer<> is a very generic name and should not pollute the
global namespace.
2017-09-16 16:37:29 +02:00

187 lines
4.4 KiB
C++

/*
Copyright (C) 2012-2016 Paul Davis
Author: David Robillard
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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <stdlib.h>
#include <unistd.h>
#include "ardour/worker.h"
#include "pbd/error.h"
#include "pbd/compose.h"
#include <glibmm/timer.h>
namespace ARDOUR {
Worker::Worker(Workee* workee, uint32_t ring_size, bool threaded)
: _workee(workee)
, _requests(threaded ? new PBD::RingBuffer<uint8_t>(ring_size) : NULL)
, _responses(new PBD::RingBuffer<uint8_t>(ring_size))
, _response((uint8_t*)malloc(ring_size))
, _sem(string_compose ("worker_semaphore%1", this).c_str(), 0)
, _thread(NULL)
, _exit(false)
, _synchronous(!threaded)
{
if (threaded) {
_thread = Glib::Threads::Thread::create(
sigc::mem_fun(*this, &Worker::run));
}
}
Worker::~Worker()
{
_exit = true;
_sem.signal();
if (_thread) {
_thread->join();
}
delete _responses;
delete _requests;
free (_response);
}
bool
Worker::schedule(uint32_t size, const void* data)
{
if (_synchronous || !_requests) {
_workee->work(*this, size, data);
return true;
}
if (_requests->write_space() < size + sizeof(size)) {
return false;
}
if (_requests->write((const uint8_t*)&size, sizeof(size)) != sizeof(size)) {
return false;
}
if (_requests->write((const uint8_t*)data, size) != size) {
return false;
}
_sem.signal();
return true;
}
bool
Worker::respond(uint32_t size, const void* data)
{
if (_responses->write_space() < size + sizeof(size)) {
return false;
}
if (_responses->write((const uint8_t*)&size, sizeof(size)) != sizeof(size)) {
return false;
}
if (_responses->write((const uint8_t*)data, size) != size) {
return false;
}
return true;
}
bool
Worker::verify_message_completeness(PBD::RingBuffer<uint8_t>* rb)
{
uint32_t read_space = rb->read_space();
uint32_t size;
PBD::RingBuffer<uint8_t>::rw_vector vec;
rb->get_read_vector (&vec);
if (vec.len[0] + vec.len[1] < sizeof(size)) {
return false;
}
if (vec.len[0] >= sizeof(size)) {
memcpy (&size, vec.buf[0], sizeof (size));
} else {
memcpy (&size, vec.buf[0], vec.len[0]);
memcpy (&size + vec.len[0], vec.buf[1], sizeof(size) - vec.len[0]);
}
if (read_space < size+sizeof(size)) {
/* message from writer is yet incomplete. respond next cycle */
return false;
}
return true;
}
void
Worker::emit_responses()
{
uint32_t read_space = _responses->read_space();
uint32_t size = 0;
while (read_space >= sizeof(size)) {
if (!verify_message_completeness(_responses)) {
/* message from writer is yet incomplete. respond next cycle */
return;
}
/* read and send response */
_responses->read((uint8_t*)&size, sizeof(size));
_responses->read(_response, size);
_workee->work_response(size, _response);
read_space -= sizeof(size) + size;
}
}
void
Worker::run()
{
void* buf = NULL;
size_t buf_size = 0;
while (true) {
_sem.wait();
if (_exit) {
free(buf);
return;
}
uint32_t size = _requests->read_space();
if (size < sizeof(size)) {
PBD::error << "Worker: no work-data on ring buffer" << endmsg;
continue;
}
while (!verify_message_completeness(_requests)) {
Glib::usleep(2000);
if (_exit) {
if (buf) free(buf);
return;
}
}
if (_requests->read((uint8_t*)&size, sizeof(size)) < sizeof(size)) {
PBD::error << "Worker: Error reading size from request ring"
<< endmsg;
continue;
}
if (size > buf_size) {
buf = realloc(buf, size);
if (buf) {
buf_size = size;
} else {
PBD::error << "Worker: Error allocating memory"
<< endmsg;
buf_size = 0; // TODO: This is probably fatal
}
}
if (_requests->read((uint8_t*)buf, size) < size) {
PBD::error << "Worker: Error reading body from request ring"
<< endmsg;
continue; // TODO: This is probably fatal
}
_workee->work(*this, size, buf);
}
}
} // namespace ARDOUR