Thread parking for Kotlin/Common

[bbrockbernd]

Allows to pause and resume thread execution. On native platforms it is based on pthread_cond_wait, on JVM it uses LockSupport.

Threads can be pre unparked (calling unpark before park cancels the parking operation). And thread can be parker with a timeout.

Suspend the current thread by calling:

Parker.park()

Resume a thread by calling:

Parker.unpark(thread)

Get current thread reference by calling:

val thread = KThread.currentThread()

Parking with timout of 500 nano seconds:

Parker.parkNanos(500)

[dkhalanskyjb]

Probably makes more sense to assert in the code that the negative number of nanos never even enters addNanosToSeconds. No reason to test the code path that will never be taken.

[dkhalanskyjb]

I'd also print the contents of https://www.man7.org/linux/man-pages/man3/errno.3.html

[dkhalanskyjb]

A stronger version of the check: if the value does not clamp, the (updatedTime - currentTime) == nanos / 1_000_000_000; if the value clamps, it's because as a Long value, it would exceed an Int. This describes what we want from addNanosToSeconds more precisely. As is, when I write internal fun Long.addNanosToSeconds(nanos: Long): Long = this + nanos / 2_000_000_000, for example, no tests fail.