> 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.
Matthias Bläsing has updated the pull request incrementally with one additional commit since the last revision: Review fix: Use correct bug id ------------- Changes: - all: https://git.openjdk.java.net/jfx/pull/458/files - new: https://git.openjdk.java.net/jfx/pull/458/files/c9ec47c9..e1de314d Webrevs: - full: https://webrevs.openjdk.java.net/?repo=jfx&pr=458&range=02 - incr: https://webrevs.openjdk.java.net/?repo=jfx&pr=458&range=01-02 Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod Patch: https://git.openjdk.java.net/jfx/pull/458.diff Fetch: git fetch https://git.openjdk.java.net/jfx pull/458/head:pull/458 PR: https://git.openjdk.java.net/jfx/pull/458
