Created attachment 151426 [details]
thread dump of hang/deadlock

In attached thread dump, looks like might be a deadlock, involving org.netbeans.api.keyring and the system classloader lock, between following two threads, #16 and #67. There's around 10 threads waiting for the classloader, including one on the EDT.

"org.netbeans.api.keyring.Keyring" #16 daemon prio=1 os_prio=-2 tid=0x0000000025240000 nid=0x2bcc waiting for monitor entry [0x000000002901e000]
  java.lang.Thread.State: BLOCKED (on object monitor)
       at org.netbeans.ModuleManager$SystemClassLoader.getResourcesImpl(Module Manager.java:690)
       - waiting to lock <0x00000006c08ef730> (a org.netbeans.ModuleManager$SystemClassLoader)
       at org.netbeans.ProxyClassLoader.getResources(ProxyClassLoader.java:390)
       ...



"pool-3-thread-1" #67 prio=5 os_prio=0 tid=0x00000000333f6000 nid=0x144c waiting on condition [0x000000004120a000]
  java.lang.Thread.State: WAITING (parking)
       at sun.misc.Unsafe.park(Native Method)
       - parking to wait for  <0x00000006d34408f8> (a org.openide.util.RequestProcessor$RPFutureTask)
       at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
       at java.util.concurrent.FutureTask.awaitDone(FutureTask.java:429)
       at java.util.concurrent.FutureTask.get(FutureTask.java:191)
       at org.netbeans.api.keyring.Keyring.read(Keyring.java:144)
       ...
       at sun.net.www.protocol.http.NegotiateAuthentication.isSupported(NegotiateAuth entication.java:102)
       - locked <0x00000006c08ef730> (a org.netbeans.ModuleManager$SystemClassLoader)
       at sun.net.www.protocol.http.AuthenticationHeader.parse(AuthenticationHeader.j ava:180)
       ...
       at org.netbeans.modules.autoupdate.updateprovider.NetworkAccess$Task$2.call( NetworkAccess.java:148)


I didn't see it happen, it was reported to me. Some info

>>
>> NB 8.0.2
>> JDK 8.1.0_25 64-bit
>> Windows 7 Pro
>> 16G physical memory
>>
>>
>>
>> From netbeans.conf:
>>
>> netbeans_default_options="-J-
> Dorg.apache.jasper.compiler.Parser.STRICT_QUOTE_ESCAPING=false -J-client
-
> J-XX:+UseG1GC -J-XX:+CMSClassUnloadingEnabled -J-Xmx4g -J-Xverify:none -
J-
> Dapple.laf.useScreenMenuBar=true -J-Dapple.awt.graphics.UseQuartz=true -
J-
> Dsun.java2d.noddraw=true -J-Dsun.java2d.dpiaware=true -J-
> Dsun.zip.disableMemoryMapping=true --laf Nimbus"
>>
>>
>>
>> I start NB with "--console new".  There is nothing in the windows command
> prompt window.