Adds a mechanism to listen to proxy transact method calls.
There are multiple use cases for it:
1) Make it easy for another process to set the worksource. The
worksource can be propagated in a thread local - this is how gmscore and soon
system server works - the worksource can then be set for all binder
calls using
Object transactStarted() {
Binder.setWorkSource(ThreadLocalWorkSourceUid.get());
return null; // No token needed.
}
void transactEnded() {
Binder.setWorkSource(null);
}
This will be used by system process and gmscore.
2) SystemUI team was interested in detecting binder calls done from the
main thread in dogfood/tests. This listener will make it easy to figure
out which thread is used.
Performance impact of transact method:
- With current code: 45ns per call
- With this code: 57ns per call
This is not significant compared to the total binder call time which is
10-100s of microseconds.
Test: unit test
Change-Id: Id0a2f52cba33b390ff83f703284b79471cc80b1c
3 files changed