Hi, I'm not completely sure about what you're asking, so I'll do my best to answer :-)
There is only one thread per process handling the events. Note that there should only be one instance of SensorManager as well (it's a singleton). It's therefore not possible to have more than one thread per process using the low-level sensor api from Java. Now to answer your question literally, yes, the filedescriptor is the same in both threads, therefore it gets closed when the thread returns. But notice that getDataChanel() is called again when the thread is re-started. getDataChanel() gives ownership of the fd to the caller (conceptually it does a "dup" before returning it). Hope this helps. Mathias On Apr 1, 4:10 pm, Huaka‘i Po <[email protected]> wrote: > Hi all, > is the file descriptor in SensorManager.java global to all threads? > > In setting up the event dispatch thread for sensor events, there is a > call > ParcelFileDescriptor fd = service.getDataChanel(); > getDataChanel() eventually winds up calling open_data_source in the > sensor framework, which returns an open Linux fd. Then the code > instantiates a new thread with a SensorThreadRunnable, part of which > is here: > > private class SensorThreadRunnable implements Runnable { > private ParcelFileDescriptor mSensorDataFd; > SensorThreadRunnable(ParcelFileDescriptor fd) { > mSensorDataFd = fd; > } > ... > > The run() method of SensorThreadRunnable later closes mSensorDataFd. > Does that close the original fd returned by getDataChanel? (i.e. is > the fd the same one in both threads, or are the semantics more like dup > () because of the Parcel stuff?) > > Thanks, > Hod --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "android-framework" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-framework?hl=en -~----------~----~----~----~------~----~------~--~---
