Extras: fixed concurrent loading of SVG icons on multiple threads (issue #459)

CHANGELOG.md

@@ -17,6 +17,8 @@ FlatLaf Change Log
   - Improved hover/pressed/selected colors of leading/trailing buttons (e.g.
     "reveal" button in password field). (issue #452)
   - Clear button no longer paints over round border. (issue #451)
+- Extras: Fixed concurrent loading of SVG icons on multiple threads. (issue
+  #459)
 
 
 ## 2.0-rc1

flatlaf-extras/src/main/java/com/formdev/flatlaf/extras/FlatSVGIcon.java

@@ -273,10 +273,12 @@ public class FlatSVGIcon
 		// since the input stream is already loaded and parsed,
 		// get diagram here and remove it from cache
 		update();
+		synchronized( FlatSVGIcon.class ) {
 			svgCache.remove( uri );
 		}
+	}
 
-	private static URI loadFromStream( InputStream in ) throws IOException {
+	private static synchronized URI loadFromStream( InputStream in ) throws IOException {
 		try( InputStream in2 = in ) {
 			return svgUniverse.loadSVG( in2, "/flatlaf-stream-" + (streamNumber++) );
 		}
@@ -475,7 +477,7 @@ public class FlatSVGIcon
 		loadFailed = (diagram == null);
 	}
 
-	static SVGDiagram loadSVG( URI uri ) {
+	static synchronized SVGDiagram loadSVG( URI uri ) {
 		// get from our cache
 		SVGDiagram diagram = svgCache.get( uri );
 		if( diagram != null )

flatlaf-testing/src/main/java/com/formdev/flatlaf/testing/FlatStressTest.java

@@ -27,6 +27,7 @@ import javax.swing.SwingUtilities;
 import javax.swing.UIManager;
 import com.formdev.flatlaf.FlatClientProperties;
 import com.formdev.flatlaf.FlatLightLaf;
+import com.formdev.flatlaf.extras.FlatSVGIcon;
 
 /**
  * @author Karl Tauber
@@ -57,6 +58,7 @@ public class FlatStressTest
 	private JComponent createStressTest() {
 		return createComboBoxStressTest();
 //		return createGetFontStressTest();
+//		return createSVGIconTest();
 	}
 
 	// for https://github.com/JFormDesigner/FlatLaf/issues/432
@@ -109,4 +111,31 @@ public class FlatStressTest
 
 		return label;
 	}
+
+	// for https://github.com/JFormDesigner/FlatLaf/issues/459
+	@SuppressWarnings( "unused" )
+	private JComponent createSVGIconTest() {
+		JLabel label = new JLabel( "test" );
+
+		Runnable runnable = () -> {
+			for(;;) {
+				FlatSVGIcon icon = new FlatSVGIcon( "com/formdev/flatlaf/demo/icons/back.svg" );
+				icon.getIconHeight();
+			}
+		};
+
+		Thread thread1 = new Thread( runnable);
+		thread1.setDaemon( true );
+		thread1.start();
+
+		Thread thread2 = new Thread( runnable);
+		thread2.setDaemon( true );
+		thread2.start();
+
+		Thread thread3 = new Thread( runnable);
+		thread3.setDaemon( true );
+		thread3.start();
+
+		return label;
+	}
 }