Fix MSVC builds freezing due to AOLayer concurrency issue

Variables accessed across threads should be atomic.

Also gave AOLayer its own thread pool and switched some lock calls to use QMutexLocker semantics.

1 files changed, 16 insertions, 9 deletions

diff --git a/src/aolayer.cpp b/src/aolayer.cpp
index 1587d289..08ee392d 100644
--- a/src/aolayer.cpp
+++ b/src/aolayer.cpp
@@ -4,6 +4,8 @@
 #include "file_functions.h"
 #include "misc_functions.h"
 
+static QThreadPool *thread_pool;
+
 AOLayer::AOLayer(QWidget *p_parent, AOApplication *p_ao_app) : QLabel(p_parent)
 {
   ao_app = p_ao_app;
@@ -22,6 +24,11 @@ AOLayer::AOLayer(QWidget *p_parent, AOApplication *p_ao_app) : QLabel(p_parent)
   preanim_timer = new QTimer(this);
   preanim_timer->setSingleShot(true);
   connect(preanim_timer, &QTimer::timeout, this, &AOLayer::preanim_done);
+
+  if (!thread_pool) {
+    thread_pool = new QThreadPool(p_ao_app);
+    thread_pool->setMaxThreadCount(8);
+  }
 }
 
 BackgroundLayer::BackgroundLayer(QWidget *p_parent, AOApplication *p_ao_app)
@@ -319,7 +326,7 @@ void AOLayer::start_playback(QString p_image)
     frame = 0;
     continuous = false;
   }
-  frame_loader = QtConcurrent::run(this, &AOLayer::populate_vectors);
+  frame_loader = QtConcurrent::run(thread_pool, this, &AOLayer::populate_vectors);
   last_path = p_image;
   while (movie_frames.size() <= frame) // if we haven't loaded the frame we need yet
     frameAdded.wait(&mutex); // wait for the frame loader to add another frame, then check again
@@ -538,11 +545,11 @@ void AOLayer::movie_ticker()
     else
       frame = 0;
   }
-  mutex.lock();
-  while (frame >= movie_frames.size() && frame < max_frames) { // oops! our frame isn't ready yet
+  {
+    QMutexLocker locker(&mutex);
+    while (frame >= movie_frames.size() && frame < max_frames) // oops! our frame isn't ready yet
       frameAdded.wait(&mutex); // wait for a new frame to be added, then check again
   }
-  mutex.unlock();
 #ifdef DEBUG_MOVIE
   qDebug() << "[AOLayer::movie_ticker] Frame:" << frame << "Delay:" << movie_delays[frame]
            << "Actual time taken from last frame:" << actual_time.restart();
@@ -552,7 +559,7 @@ void AOLayer::movie_ticker()
 }
 
 void AOLayer::populate_vectors() {
-    while (movie_frames.size() < max_frames && !exit_loop) {
+    while (!exit_loop && movie_frames.size() < max_frames) {
         load_next_frame();
 #ifdef DEBUG_MOVIE
         qDebug() << "[AOLayer::populate_vectors] Loaded frame" << movie_frames.size();
@@ -562,12 +569,12 @@ void AOLayer::populate_vectors() {
 }
 
 void AOLayer::load_next_frame() {
-    //QMutexLocker locker(&mutex);
-    mutex.lock();
+  {
+    QMutexLocker locker(&mutex);
     movie_frames.append(this->get_pixmap(m_reader.read()));
     movie_delays.append(m_reader.nextImageDelay());
-    mutex.unlock();
-    frameAdded.wakeAll();
+  }
+  frameAdded.wakeAll();
 }
 
 void CharLayer::preanim_done()