moved things around and started rewriting render backend

app/threading/threadpool.cpp

@@ -0,0 +1,138 @@
+/***
+
+  Olive - Non-Linear Video Editor
+  Copyright (C) 2019 Olive Team
+
+  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 3 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, see <http://www.gnu.org/licenses/>.
+
+***/
+
+#include "threadpool.h"
+
+OLIVE_NAMESPACE_ENTER
+
+ThreadPool::ThreadPool(QThread::Priority priority, int threads, QObject *parent) :
+  QObject(parent)
+{
+  all_threads_.resize(threads ? threads : QThread::idealThreadCount());
+
+  // Create threads
+  for (int i=0; i<all_threads_.size(); i++) {
+    ThreadPoolThread* t  = new ThreadPoolThread(this);
+
+    // Add to vector of all threads
+    all_threads_[i] = t;
+
+    // Append to list of available threads
+    available_threads_.push_back(t);
+
+    // Connect done signal
+    connect(t, &ThreadPoolThread::Done, this, &ThreadPool::ThreadDone);
+
+    // Start the thread at the given priority
+    t->start(priority);
+  }
+}
+
+ThreadPool::~ThreadPool()
+{
+  foreach (ThreadPoolThread* thread, all_threads_) {
+    thread->Cancel();
+    thread->wait();
+    delete thread;
+  }
+
+  RunNext();
+}
+
+void ThreadPool::AddTicket(RenderTicketPtr ticket, bool prioritize)
+{
+  if (prioritize) {
+    ticket_queue_.push_front(ticket);
+  } else {
+    ticket_queue_.push_back(ticket);
+  }
+
+  RunNext();
+}
+
+void ThreadPool::RunNext()
+{
+  while (!ticket_queue_.empty() && !available_threads_.empty()) {
+    // Run function
+    RenderTicketPtr ticket = ticket_queue_.front();
+    ticket_queue_.pop_front();
+
+    if (!ticket->WasCancelled()) {
+      ThreadPoolThread* thread = available_threads_.front();
+      available_threads_.pop_front();
+
+      // Run the ticket in the thread, which actually just calls our virtual function RunTicket
+      thread->RunTicket(ticket);
+    }
+  }
+}
+
+void ThreadPool::ThreadDone()
+{
+  ThreadPoolThread* thread = static_cast<ThreadPoolThread*>(sender());
+
+  available_threads_.push_back(thread);
+
+  RunNext();
+}
+
+ThreadPoolThread::ThreadPoolThread(ThreadPool *parent)
+{
+  pool_ = parent;
+  cancelled_ = false;
+
+  // Ensures mutex is definitely locked by the time the thread is running
+  mutex_.lock();
+}
+
+ThreadPoolThread::~ThreadPoolThread()
+{
+  mutex_.unlock();
+}
+
+void ThreadPoolThread::RunTicket(RenderTicketPtr ticket)
+{
+  mutex_.lock();
+  ticket_ = ticket;
+  wait_cond_.wakeAll();
+  mutex_.unlock();
+}
+
+void ThreadPoolThread::Cancel()
+{
+  cancelled_ = true;
+  wait_cond_.wakeAll();
+}
+
+void ThreadPoolThread::run()
+{
+  while (!cancelled_) {
+    wait_cond_.wait(&mutex_);
+
+    if (ticket_) {
+      pool_->RunTicket(ticket_);
+      ticket_ = nullptr;
+    }
+
+    emit Done();
+  }
+}
+
+OLIVE_NAMESPACE_EXIT