On Thu, 8 Apr 2021 20:27:45 GMT, Kevin Rushforth <k...@openjdk.org> wrote:
>> The functions from FileSystemJava are called from different threads the
>> root problem manifests because the JNI FindClass function behaves
>> differently when called from a context that is the ancestor of a java
>> frame compared to when called in isolation.
>>
>> A segmentation fault is observed when local storage of a webview is
>> accessed. At that time a new native thread is spun up and that sets up
>> the local storage, by calling into the JVM via
>> WTF::FileSystem::makeAllDirectories. At that point GetFileSystemClass is
>> invoked to get a referenc to the java implementation of the FileSystem.
>> As this is is called from a new native thread (no java context
>> available), JNI uses the system classloader to locate the class. This
>> fails if the JavaFX modules are not on the boot module/class path.
>>
>> Instead on relying on fetching the class reference everytime it is
>> needed, this change fetches it once when the JavaFX library is loaded
>> and stores it in the WTF namespace.
>>
>> In addition to this it was observed, that there is no attachment to the
>> JVM done when calling into the filesystem. No fault was observed, but
>> the JNI specs indicate, that the JNIEnv interface is only valid when
>> attached.
>
> tests/system/src/testapp7/java/mymod/myapp7/LocalStorageAccessWithModuleLayer.java
> line 92:
>
>> 90: }
>> 91: });
>> 92:
>> webview.getEngine().load(LocalStorageAccessWithModuleLayer.class.getResource("/LocalStorageAccess.html").toExternalForm());
>
> This fails to find the resource when I run the test via gradle. I recommend
> putting it in the same package as the class and removing the leading `/`
> (e.g., see the FXML resources in `testapp6` or `testscriptapp1`).
Can you tell me how you ran it? I ensured, that the test failed with a segfault
before continuing with the fix. While I did that I indeed placed the file in
the wrong directory, but currently I see no test failures locally. I run:
./gradlew -PFULL_TEST=true -PUSE_ROBOT=true :systemTests:cleanTest
:systemTests:test --tests test.com.sun.webkit.LocalStorageAccessTest
to only invoke the new test. I'll move the file to the package, but I'd like to
understand where I went wrong.
-------------
PR: https://git.openjdk.java.net/jfx/pull/458
