This is a new public API for developers to opt-in to strict rules
about what they're allowed to do on certain threads. (this is the
public face of the @hide dalvik.system.BlockGuard, added recently...)
In practice this will be used for developers to opt-in to declaring
that they don't want to be allowed to do various operations (such as
disk I/O or network operations) on their main UI threads. (these
operations are often accidental, or even when they are fast come with
a good chance of being slow or very slow in some cases....)
Implementation wise, this is just a thread-local integer that has a
bitmask of the things that aren't allowed, and more bits for saying
what the violation penalty is. The penalties, of which multiple can
be chosen, include:
* logging
* dropbox uploading for analysis/reporting
* annoying dialog
* full-on crashing
These are all only very roughly implemented at this point, but all
parts now minimally work end-to-end now, so this is a good checkpoint
commit before this gets too large.
Future CLs will polish all the above 4 penalties, including
checksumming of stacktraces and minimizing penalties for duplicate
violations.
Change-Id: Icbe61a2e950119519e7364030b10c3c28d243abe
438d059512