FULL PRODUCT VERSION :
java version "1.8.0_25"
Java(TM) SE Runtime Environment (build 1.8.0_25-b17)
Java HotSpot(TM) 64-Bit Server VM (build 25.25-b02, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Linux 3.13.0-37-generic #64-Ubuntu SMP Mon Sep 22 21:28:38 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux

A DESCRIPTION OF THE PROBLEM :
ConcurrentHashMap is stuck in an endless loop in computeIfAbsent - the for-loop starting at line 1649.

tab=[
null,
null,
null,
null,
null,
null,
null,
null,
null=null,
null,
null,
null,
null,
class com.<redacted>.ClipboardPrepareImportService=com.<redacted>.ClipboardPrepareImportService@2ae00cd3,
null,
interface com.<redacted>.BackendConnectionGateway=Mock for BackendConnectionGateway, hashCode: 1117386246]

h=833174808

* the first if (line 1651) is skipped because tab is neither null nor empty
* the second if as well because f = tabAt(....) is equal to null=null (CHM$ReservationNode)
* the third if (line 1670) as well because fh = -3 (RESERVED)
* we fall back into the else block at line 1672

* tabAt(tab, i) == f is true (i=8) at line 1675
* the if at line 1676 is not satisfied because fh = -3
* the if at line 1696 is also not satisfied because f is an CHM$ReservationNode

* binCount = 0 so the if at line 1710 is also not satisfied.

Aaaand back to the beginning of the loop at 1649.


The searched value is not yet present when computeIfPresent is called -> the mapper function should be called but that never happens.

This only happens occasionally.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The mapping function is called and the computed value is added to the map and returned.
ACTUAL -
Endless loop.

REPRODUCIBILITY :
This bug can be reproduced occasionally.