Make for somewhat cleaner shutdown.

[nageru] / jpeg_frame_view.cpp

diff --git a/jpeg_frame_view.cpp b/jpeg_frame_view.cpp
index ef1cded69d9dc98fcf4d26864c6ac3eef76bd667..bc71d00a570e4372a0a679f4f22f04c0b1810a99 100644 (file)
--- a/jpeg_frame_view.cpp
+++ b/jpeg_frame_view.cpp
@@ -44,12 +44,14 @@ struct LRUFrame {
        size_t last_used;
 };
 
+thread JPEGFrameView::jpeg_decoder_thread;
 mutex cache_mu;
 map<JPEGID, LRUFrame, JPEGIDLexicalOrder> cache;  // Under cache_mu.
 condition_variable any_pending_decodes, cache_updated;
 deque<pair<JPEGID, JPEGFrameView *>> pending_decodes;  // Under cache_mu.
 atomic<size_t> event_counter{0};
 extern QGLWidget *global_share_widget;
+extern atomic<bool> should_quit;
 
 shared_ptr<Frame> decode_jpeg(const string &filename)
 {
@@ -193,20 +195,21 @@ shared_ptr<Frame> decode_jpeg_with_cache(JPEGID id, CacheMissBehavior cache_miss
        return frame;
 }
 
-void jpeg_decoder_thread()
+void jpeg_decoder_thread_func()
 {
        size_t num_decoded = 0, num_dropped = 0;
 
        pthread_setname_np(pthread_self(), "JPEGDecoder");
-       for ( ;; ) {
+       while (!should_quit.load()) {
                JPEGID id;
                JPEGFrameView *dest;
                CacheMissBehavior cache_miss_behavior = DECODE_IF_NOT_IN_CACHE;
                {
                        unique_lock<mutex> lock(cache_mu);  // TODO: Perhaps under another lock?
                        any_pending_decodes.wait(lock, [] {
-                               return !pending_decodes.empty();
+                               return !pending_decodes.empty() || should_quit.load();
                        });
+                       if (should_quit.load()) break;
                        id = pending_decodes.front().first;
                        dest = pending_decodes.front().second;
                        pending_decodes.pop_front();
@@ -229,8 +232,9 @@ void jpeg_decoder_thread()
                        // put directly into the cache from VideoStream.
                        unique_lock<mutex> lock(cache_mu);
                        cache_updated.wait(lock, [id] {
-                               return cache.count(id) != 0;
+                               return cache.count(id) != 0 || should_quit.load();
                        });
+                       if (should_quit.load()) break;
                        found_in_cache = true;  // Don't count it as a decode.
 
                        auto it = cache.find(id);
@@ -267,6 +271,12 @@ void jpeg_decoder_thread()
        }
 }
 
+void JPEGFrameView::shutdown()
+{
+       any_pending_decodes.notify_all();
+       jpeg_decoder_thread.join();
+}
+
 JPEGFrameView::JPEGFrameView(QWidget *parent)
        : QGLWidget(parent, global_share_widget) {
 }
@@ -304,7 +314,7 @@ void JPEGFrameView::initializeGL()
        static once_flag once;
        call_once(once, [] {
                resource_pool = new ResourcePool;
-               std::thread(&jpeg_decoder_thread).detach();
+               jpeg_decoder_thread = std::thread(jpeg_decoder_thread_func);
        });
 
        ImageFormat inout_format;