Merge lp:~fboucault/qt-halide/fix_input_reuse into lp:qt-halide

[Florian Boucault]

Fix deadlock when a function was first disabled then enabled due to the reuse of the input as output.

[Ugo Riboni (uriboni)]

LGTM

review: Approve

=== modified file 'src/QtHalide/halide_transform_worker.cpp'
--- src/QtHalide/halide_transform_worker.cpp	2015-06-10 09:45:20 +0000
+++ src/QtHalide/halide_transform_worker.cpp	2015-06-12 13:09:10 +0000
@@ -29,7 +29,8 @@
     QObject(0),
     m_transform(transform),
     m_thread(new QThread),
-    m_outputImage(new HalideImageData)
+    m_outputImage(new HalideImageData),
+    m_outputImageIsInput(false)
 {
 }
 
@@ -49,8 +50,10 @@
             m_outputImage = lastOutput;
         } else if (inputImage) {
             m_outputImage = inputImage->data();
+            m_outputImageIsInput = true;
         } else {
             m_outputImage.reset(new HalideImageData);
+            m_outputImageIsInput = false;
         }
         Q_EMIT computeFinished(m_outputImage);
     } else {
@@ -187,6 +190,12 @@
         lastOutput->lock.unlock();
     }
 
+    // If m_outputImage is a reference to an HalideImageData used as input, it
+    // should not be written on, replace it with a new empty one instead
+    if (m_outputImageIsInput) {
+        m_outputImage.reset(new HalideImageData);
+        m_outputImageIsInput = false;
+    }
     // FIXME: only useful if output is going to be used for reading while being
     // written on again by this worker
     qSwap(m_outputImage, functionsData.last()->output);

=== modified file 'src/QtHalide/halide_transform_worker.h'
--- src/QtHalide/halide_transform_worker.h	2015-04-08 15:48:49 +0000
+++ src/QtHalide/halide_transform_worker.h	2015-06-12 13:09:10 +0000
@@ -92,6 +92,7 @@
     QHash<HalideFunction*, QSharedPointer<HalideFunctionData> > m_cache;
     QThread* m_thread;
     QSharedPointer<HalideImageData> m_outputImage;
+    bool m_outputImageIsInput;
     static QMutex s_jitLock;
 };
 

=== modified file 'tests/unit/tst_function_list_model.qml'
--- tests/unit/tst_function_list_model.qml	2015-04-08 15:48:49 +0000
+++ tests/unit/tst_function_list_model.qml	2015-06-12 13:09:10 +0000
@@ -151,6 +151,20 @@
             compareAllPixelsWithColor(255, 128, 128, 255, "output does not match expected output");
         }
 
+        function test_disabled_then_enabled_then_update() {
+            red.enabled = false;
+            red.channel = 2;
+            transform.functions = [red];
+            spy.waitForUpdate();
+            compareAllPixelsWithColor(128, 128, 128, 255, "output is not equal to input when no function is enabled");
+            red.enabled = true;
+            spy.waitForUpdate();
+            compareAllPixelsWithColor(128, 128, 255, 255, "output does not match expected output");
+            red.channel = 0;
+            spy.waitForUpdate();
+            compareAllPixelsWithColor(255, 128, 128, 255, "output does not match expected output");
+        }
+
         function test_all_disabled() {
             red.enabled = false;
             green.enabled = false;