Investigate flaky test-timers-blocking-callback

[Trott]

https://ci.nodejs.org/job/node-test-commit-freebsd/3639/nodes=freebsd10-64/console

not ok 922 parallel/test-timers-blocking-callback
# 
# assert.js:89
#   throw new assert.AssertionError({
#   ^
# AssertionError: false == true
#     at Timeout.blockingCallback [as _onTimeout] (/usr/home/iojs/build/workspace/node-test-commit-freebsd/nodes/freebsd10-64/test/parallel/test-timers-blocking-callback.js:52:5)
#     at tryOnTimeout (timers.js:232:11)
#     at Timer.listOnTimeout (timers.js:202:5)
  ---
  duration_ms: 0.659

[Trott]

Also flaky on CentOS 5 (32-bit):

https://ci.nodejs.org/job/node-test-commit-linux/5269/nodes=centos5-32/console

not ok 950 parallel/test-timers-blocking-callback
# 
# assert.js:85
#   throw new assert.AssertionError({
#   ^
# AssertionError: false == true
#     at Timeout.blockingCallback [as _onTimeout] (/home/iojs/build/workspace/node-test-commit-linux/nodes/centos5-32/test/parallel/test-timers-blocking-callback.js:52:5)
#     at tryOnTimeout (timers.js:232:11)
#     at Timer.listOnTimeout (timers.js:202:5)
  ---
  duration_ms: 1.226

[Trott]

/cc @whitlockjc

[Trott]

/cc @Fishrock123, @misterdjules

[misterdjules]

Thanks for the heads up @Trott! This test is definitely inherently flaky. My apologies for that, as I participated in its design.

I'm looking into finding a way to make it non-flaky, I'll keep you posted.

[MylesBorins]

another failure https://ci.nodejs.org/job/node-test-commit-freebsd/4890/nodes=freebsd10-64/tapTestReport/

[Trott]

Three more freebsd10-64 on CI today:

• https://ci.nodejs.org/job/node-test-commit-freebsd/5013/nodes=freebsd10-64/console
• https://ci.nodejs.org/job/node-test-commit-freebsd/5024/nodes=freebsd10-64/console
• https://ci.nodejs.org/job/node-test-commit-freebsd/5030/nodes=freebsd10-64/console

[misterdjules]

@Trott As indicated in one of my recents comments, I expected more failures after the latest changes in that test, so in some ways it's good to have that confirmation recorded here, thanks for that!

[Trott]

Yes, you definitely called it.

(I think I might have a solution soon, but I've definitely thought that before and been wrong, so don't hold me to it.)