813842 - GonkSwitch needs to be rewritten

Status: RESOLVED WONTFIX

(Firefox OS Graveyard :: General, defect)

Description

[Dave Hylands [:dhylands]]

Currently, the way that GonkSwitch is written, it has data structures which are allocated and maintained by the IOThread, but which are accessed by the MainThread.

Bug 751423 tried to introduce a Monitor to synchronize things, but this has resulted in some hangs, see bug 812880 and bug 813831

I think that we should remove the Monitor lock altogether. We should have the data structures on the IOThread send events to MainThread to update a cache which reflects the state of the switches. MainThread should never directly access the data structures maintained on IOThread and vice-versa.

Comment 1

[Marco Chen [:mchen]]

Hi Dave,

What i know for this change are

  1. to have a new static variable for caching the switch state of each switch devices in main thread context.
  2. to modify GonkSwitch.cpp::GetCurrentSwitchState() as that if sSwitchObserver is not exist already then directly reading the specific sys node of indicated switch device.

Are these as what you need? Thanks.

Comment 2

[BMO Automation]

Firefox OS is not being worked on