RFR: 8267926: AsyncLogGtest.java fails on assert with: decorator was not part of the decorator set specified at creation. [v3]

[David Holmes]

On Mon, 31 May 2021 17:09:48 GMT, Xin Liu <xliu at openjdk.org> wrote:

>> The root cause of the intermittent failure is that _decorators in LogDecorations 
>> may be inconsistent with LogOutput::_decorators. It could happen when gtest disables a
>> Log output via set_log_config(TestLogFileName, "all=off").
>> 
>> Since we copy the entire logDecorations, it's reasonable to copy _decorator as well. 
>> LogDecorator is a bitmask of uint. It's even smaller than a reference on LP64 platforms.
>> 
>> This patch not only fixes intermittent crash in JDK-8267926, but also fixes JDK-8267952.
>> Two hazards of async logging in `LogConfiguration::configure_output` are eliminated. 
>> This patch also adds a storestore barrier to make sure it's safe on weak consistency machines.
>
> Xin Liu has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Increase reader's counter before creating LogDecoration.

I put the latest patch through our tier 1-4 testing and it crashed in tier 3 on Linux-Aarch64:

#
# A fatal error has been detected by the Java Runtime Environment:
#
#  SIGSEGV (0xb) at pc=0x0000ffff40820720, pid=3972473, tid=3972481
#
# JRE version: Java(TM) SE Runtime Environment (17.0) (fastdebug build 17-internal+0-LTS-2021-05-31-2211099.david.holmes.jdk-dev4.git)
# Java VM: Java HotSpot(TM) 64-Bit Server VM (fastdebug 17-internal+0-LTS-2021-05-31-2211099.david.holmes.jdk-dev4.git, mixed mode, tiered, compressed oops, compressed class ptrs, g1 gc, linux-aarch64)
# Problematic frame:
# C  [libc.so.6+0x60720]  flockfile+0x0
#
# Core dump will be written. Default location: Core dumps may be processed with "/opt/core.sh %p" (or dumping to /opt/mach5/mesos/work_dir/slaves/a4f8fba9-f017-4328-b286-c66b6a97143d-S808/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/42993029-a18a-48c4-9a4d-108aee7b3811/runs/a38508fe-5d43-48ad-b70a-61f3e712fcd8/testoutput/test-support/jtreg_open_test_hotspot_jtreg_hotspot_misc/scratch/0/core.3972473)
#
# If you would like to submit a bug report, please visit:
#   https://bugreport.java.com/bugreport/crash.jsp
#

---------------  S U M M A R Y ------------

Command Line: -XX:+ExecutingUnitTests -Xlog:async 

Host: AArch64, 6 cores, 46G, Oracle Linux Server release 8.3
Time: Mon May 31 22:37:04 2021 UTC elapsed time: 3.758723 seconds (0d 0h 0m 3s)

---------------  T H R E A D  ---------------

Current thread (0x0000aaadf32b1e10):  Thread "AsyncLog Thread" [stack: 0x0000fffefdaa0000,0x0000fffefdca0000] [id=3972481]

Stack: [0x0000fffefdaa0000,0x0000fffefdca0000],  sp=0x0000fffefdc9e510,  free space=2041k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
C  [libc.so.6+0x60720]  flockfile+0x0
V  [libjvm.so+0x1508058]  LogFileOutput::write_blocking(LogDecorations const&, char const*)+0x38
V  [libjvm.so+0x1502764]  AsyncLogWriter::run()+0x2c0
V  [libjvm.so+0x1a49d08]  Thread::call_run()+0xf8
V  [libjvm.so+0x1766f18]  thread_native_entry(Thread*)+0x108
C  [libpthread.so.0+0x76e0]  start_thread+0x198

-------------

PR: https://git.openjdk.java.net/jdk/pull/4257