liblog: resolve deadlocks
Although ever present, an increased regression introduced with
commit 0e2fe422a1bd22b751884e1d5418bfc76844c2d4 (liblog: logd:
support logd.timestamp = monotonic).
A signal handler can interrupt in locked context, if log is written
in the signal handler, we are in deadlock. Block signals while we
are locked. Separate out timestamp lock from is loggable lock to
reduce contention situations. Provide a best-guess response if
lock would fail in timestamp path.
Bug: 25563384
Change-Id: I6dccd6b99ebace1c473c03a785a35c63ed5c6a8a
5 files changed