diff options
Diffstat (limited to 'tests')
-rw-r--r-- | tests/org.eclipse.swt.tests/JUnit Tests/org/eclipse/swt/tests/junit/memoryleak/Test_Memory_Leak.java | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/tests/org.eclipse.swt.tests/JUnit Tests/org/eclipse/swt/tests/junit/memoryleak/Test_Memory_Leak.java b/tests/org.eclipse.swt.tests/JUnit Tests/org/eclipse/swt/tests/junit/memoryleak/Test_Memory_Leak.java new file mode 100644 index 0000000000..b6a0acf69b --- /dev/null +++ b/tests/org.eclipse.swt.tests/JUnit Tests/org/eclipse/swt/tests/junit/memoryleak/Test_Memory_Leak.java @@ -0,0 +1,64 @@ +package org.eclipse.swt.tests.junit.memoryleak; + +import org.eclipse.swt.SWT; +import org.eclipse.swt.browser.Browser; +import org.eclipse.swt.layout.FillLayout; +import org.eclipse.swt.widgets.Display; +import org.eclipse.swt.widgets.Shell; +import org.junit.Test; + +/** + * Test Widgets for memory leaks. Used when updating dispose logic. + * + * Due to lack of better alternative, the current mechanism creates & disposes a widget in a loop. + * If the test makes it to the end without crashing your system, then you have no (major?) leaks. + * + * Run these on demand if updating dispose logic of a particular widget. + * + * Note: + * - The tests are a bit long, so they're not part of the main test suite. + * - Note, JNI != Java memory leaks. JNI leaks are not detected by Java profilers as they occur *outside* of the heap. + * Finding JNI leaks is not a trivial matter as typical C memory tools see the JVM as a memory leak itself. + * It's possible thou. Have not tried myself but see: + * https://stackoverflow.com/questions/33334126/how-to-find-memory-leaks-in-java-jni-c-process + * https://gdstechnology.blog.gov.uk/2015/12/11/using-jemalloc-to-get-to-the-bottom-of-a-memory-leak/ + */ +public class Test_Memory_Leak { + + static int COUNT_PRINT_PER_ROW = 50; + + /** + * Create and dispose Browser instances. + * + * If this test runs at linear speed and passes, then it's fairly safe to say you have no memory leaks. + * A typical run will take 5 minutes. + * + * If you have a memory leak in the dispoal logic, then the loop eventually slows down and the test crashes. + * You would see 'memory pressure' errors. The Java process of the jUnit would grow significantly (100's of mbs) + * On my machine with Intel i7 & 16 GB of ram, this occurs at the ~420th iteration. + * (although with my testing, without memory leaks, it grows a little bit (by 100mb by end of test)). + */ + @Test + public void test_Browser() { + Display display = new Display (); + Shell shell = new Shell(display); + shell.setLayout(new FillLayout()); + shell.open (); + + Browser browser; + int count = 50_000; + + for (int i = 1; i <= count; i++) { + browser = new Browser(shell, SWT.None); + browser.setUrl("http://www.google.com"); + while (display.readAndDispatch()) { + // This loop is needed because some disposal is delayed and done asynchronously in main loop. + // This loop typically performs ~12 iterations. + } + if (i != count) browser.dispose(); + if (i % (COUNT_PRINT_PER_ROW) == 0) System.out.println(); + System.out.print(i+ " "); + } + System.out.println(); + } +} |