[TS-4487] Haven't check the change of lock after return from wbe callback

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 7.0.0
• Component/s: SSL
• Assignee: Chao Xu
• Reporter: Chao Xu
• Created: 27/May/16 08:28
• Updated: 07/Nov/16 23:26
• Resolved: 08/Sep/16 16:04

Description

the code:

int64_t r = vc->load_buffer_and_write(towrite, wattempted, total_written, buf, needs);

At the end of write_to_net_io,

    if (!buf.reader()->read_avail()) {  // should check needs==0
      write_disable(nh, vc);
      return;
    }

    if ((needs & EVENTIO_WRITE) == EVENTIO_WRITE) {
      write_reschedule(nh, vc);
    }
    if ((needs & EVENTIO_READ) == EVENTIO_READ) {
      read_reschedule(nh, vc);
    }
    return;

another issue in write_to_net_io(): did not check the change of lock at the return callback with wbe.

  if (s->vio.ntodo() <= 0) {
    write_signal_done(VC_EVENT_WRITE_COMPLETE, nh, vc);
    return;
  } else if (signalled && (wbe_event != vc->write_buffer_empty_event)) {
    // @a signalled means we won't send an event, and the event values differing means we
    // had a write buffer trap and cleared it, so we need to send it now.
    if (write_signal_and_update(wbe_event, vc) != EVENT_CONT)
      return;
    // ============> did not check the change of lock at the return callback with wbe.
  } else if (!signalled) {
    if (write_signal_and_update(VC_EVENT_WRITE_READY, vc) != EVENT_CONT) {
      return;
    }

    // change of lock... don't look at shared variables!
    if (lock.get_mutex() != s->vio.mutex.get()) {
      write_reschedule(nh, vc);
      return;
    }
  }

Issue Links

• links to: GitHub Pull Request #673
• links to: GitHub Pull Request #754