Regarding ThreadCpuTimeArray.java: The test starts 10 threads, each of which
does some computation, then blocks. When all threads are blocked, the test
sleeps for 200ms, then checks that less than 100ns of CPU time in userspace
elapse over the course of the sleep; AFAICT, the 100ns of slop is because a
thread indicates that it's in the WAITING state before it actually blocks, and
because signals can cause threads to be temporarily woken. gVisor's CPU clocks
have a granularity of 10ms (the interval of Kernel.cpuClockTicker is
//pkg/abi/linux.ClockTick), so a single tick pushes the test over the
threshold.
PiperOrigin-RevId: 333830287
Added a README describing what these tests are, how they work and how to run
them locally. Also reorganized the exclude files into a directory.
PiperOrigin-RevId: 332079697
Jamie Liu
Ayush Ranjan