tree d78bab11c11aba3c79c6b66a944699fb591a39dd
parent bc2d7e06e72c8f3a984b234175a1b451e9c25c51
author Elliott Hughes <enh@google.com> 1478828627 -0800
committer Elliott Hughes <enh@google.com> 1478978260 -0800

init start time tracking.

With this change, init sets a property "init.start" to show the
CLOCK_BOOTTIME time at which init itself started, and for each service
an "init.svc.<name>.start" property to show the CLOCK_BOOTTIME time at
which that service was most recently started.

These times can be used by tools like bootstat to track boot time.

As part of this change, move init over to std::chrono. Also, rather than
make the command-line argument handling more complex, I've switched to
using an environment variable for communication between first- and
second-stage init, and added another environment variable to pass the
start time of the first stage through to the second stage.

Bug: http://b/32780225
Test: manual
Change-Id: Ia65a623e1866ea688b9a5433d6507926ce301dfe