eval & others nodes add fields to wrong point when in batch

[phemmer]

Input data:

test v=1i 0s
test v=2i 1s

Script:

var data = stream|from().measurement('test')
	|window().period(1s).every(0s)
data
	|eval(lambda: "v" + 1).keep().as('v_plus_one')
	|log()
data
	|eval(lambda: "v" + 2).keep().as('v_plus_two')
	|log()

Output:

[test.tick:log4] 2017/05/16 10:52:22 I!  {"name":"test","tmax":"1970-01-01T00:00:00Z","points":[{"time":"1970-01-01T00:00:00Z","fields":{"v":1,"v_plus_two":3},"tags":{}}]}
[test.tick:log4] 2017/05/16 10:52:22 I!  {"name":"test","tmax":"1970-01-01T00:00:01Z","points":[{"time":"1970-01-01T00:00:01Z","fields":{"v":2,"v_plus_one":3,"v_plus_two":4},"tags":{}}]}
[test.tick:log6] 2017/05/16 10:52:22 I!  {"name":"test","tmax":"1970-01-01T00:00:00Z","points":[{"time":"1970-01-01T00:00:00Z","fields":{"v":1,"v_plus_two":3},"tags":{}}]}
[test.tick:log6] 2017/05/16 10:52:22 I!  {"name":"test","tmax":"1970-01-01T00:00:01Z","points":[{"time":"1970-01-01T00:00:01Z","fields":{"v":2,"v_plus_one":3,"v_plus_two":4},"tags":{}}]}

Notice that some of the points have both v_plus_one and v_plus_two, and that none of the points have just v_plus_one.
You may need to run this a few times as it is a race condition

I noticed this while fixing the map race reported in #1369. The design pattern in the stateDuration, eval, default node, and others results in a race as multiple nodes all end up iterating over the same Batch object, and thus add data to the wrong point.

[desa]

@phemmer Good find. Any thoughts on what the expected behavior should be?

[phemmer]

[test.tick:log4] 2017/05/16 10:52:22 I!  {"name":"test","tmax":"1970-01-01T00:00:00Z","points":[{"time":"1970-01-01T00:00:00Z","fields":{"v":1,"v_plus_one":2},"tags":{}}]}
[test.tick:log6] 2017/05/16 10:52:22 I!  {"name":"test","tmax":"1970-01-01T00:00:00Z","points":[{"time":"1970-01-01T00:00:00Z","fields":{"v":1,"v_plus_two":3},"tags":{}}]}
[test.tick:log4] 2017/05/16 10:52:22 I!  {"name":"test","tmax":"1970-01-01T00:00:01Z","points":[{"time":"1970-01-01T00:00:01Z","fields":{"v":2,"v_plus_one":3},"tags":{}}]}
[test.tick:log6] 2017/05/16 10:52:22 I!  {"name":"test","tmax":"1970-01-01T00:00:01Z","points":[{"time":"1970-01-01T00:00:01Z","fields":{"v":2,"v_plus_two":4},"tags":{}}]}