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+Native tests for 'perfprofd'. Please run with
+
+   runtest --path=system/extras/perfprofd/tests
+
+(where runtest == $ANDROID_BUILD_TOP"/development/testrunner/runtest.py).
+
+Notes:
+
+1. Several of the testpoints in this unit tests perform a live 'simpleperf'
+run on the device (if you are using a userdebug build, simpleperf should
+already be available in /system/xbin/simpleperf).
+
+2. Part of the test is a system-wide profile, meaning that you will
+need to run 'adb root' prior to test execution.
+
+3. The daemon under test, perfprofd, is broken into a main function, a
+"core" library, and a "utils library. Picture:
+
+	+-----------+   perfprofdmain.o
+	| perfprofd |
+	| main()    |   1-liner; calls perfprofd_main()
+	+-----------+
+	   |
+	   v
+	+-----------+   perfprofdcore.a
+	| perfprofd |
+	| core      |   most of the interesting code is here;
+	|           |   calls into utils library when for
+	+-----------+   operations such as sleep, log, etc
+	   |
+	   v
+	+-----------+   perfprofdutils.a
+	| perfprofd |
+	| utils     |   real implementations of perfprofd_sleep,
+	|           |   perfprofd_log_* etc
+	+-----------+
+
+Because the daemon tends to spend a lot of time sleeping/waiting,
+it is impractical to try to test it directly. Instead we insert a
+mock utilities layer and then have a test driver that invokes the
+daemon main function. Picture for perfprofd_test:
+
+	+----------------+   perfprofd_test.cc
+	| perfprofd_test |
+	|                |   makes calls into perfprofd_main(),
+	+----------------+   then verifies behavior
+	   |
+	   v
+	+-----------+   perfprofdcore.a
+	| perfprofd |
+	| core      |   same as above
+	+-----------+
+	   |
+	   v
+	+-----------+   perfprofdmockutils.a
+	| perfprofd |
+	| mockutils |   mock implementations of perfprofd_sleep,
+	|           |   perfprofd_log_* etc
+	+-----------+
+
+The mockup versions of perfprofd_sleep() and  perfprofd_log_* do
+simply log the fact that they are called; the test driver can
+then examine the log to make sure that the daemon is doing
+what it is supposed to be doing.