On Mon, 24 Mar 2025 18:30:56 GMT, Martin Fox <m...@openjdk.org> wrote:
>> There is an undocumented limit on nesting calls to CFRunLoopRun (or the >> equivalent wrapper NSRunLoop methods). When the limit is hit the OS >> terminates the Java app. The situation arises when a JavaFX app creates too >> many nested event loops from within Platform.runLater runnables. >> >> This PR doesn't change the limit (which is 250+ nested loops) but it does >> throw an exception just before the limit is reached so a JavaFX developer >> will get a useful Java stack trace instead of an OS crash log. >> >> On the Mac the nested event loop has two stages: first we ask the run loop >> to run, then we pull an event out and process it. A Platform.runLater >> runnable is executed in the first stage so if the runnable starts a new >> nested event loop the system will re-enter CFRunLoopRun. The same isn't true >> if an input event handler starts a new nested event loop; at that point >> we're in stage two and are past the call to CFRunLoopRun. > > Martin Fox has updated the pull request incrementally with one additional > commit since the last revision: > > Lower limit on run loop nesting I still not sure why anyone would need to create that many (>200) nested event loops. So +1 for checking that on win/linux as well, possibly using the same constant (I would like to see a constant, maybe `REASONABLE_NUMBER_OF_NESTED_EVENT_LOOPS` ) ------------- PR Comment: https://git.openjdk.org/jfx/pull/1741#issuecomment-2749254584
