Safely declare Netty AttributeKeys

[dagnir]

This commit prevents the Netty client from throwing an exception in cases where
it tries to declare an attribute key and the key already exists. This can happen
when separate instances of the SDK are loaded by different classloaders, but the
Netty classes loaded by a third and shared by the other classloaders.

Fixes #1886

Description

Motivation and Context

Testing

Screenshots (if appropriate)

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)

Checklist

• I have read the CONTRIBUTING document
• Local run of mvn install succeeds
• My code follows the code style of this project
• My change requires a change to the Javadoc documentation
• I have updated the Javadoc documentation accordingly
• I have read the README document
• I have added tests to cover my changes
• All new and existing tests passed
• A short description of the change has been added to the CHANGELOG
• My change is to implement 1.11 parity feature and I have updated LaunchChangelog

License

• I confirm that this pull request can be released under the Apache 2 license

[sonarcloud]

Kudos, SonarCloud Quality Gate passed!

0 Bugs
0 Vulnerabilities (and 0 Security Hotspots to review)
0 Code Smells

100.0% Coverage
0.0% Duplication

The version of Java (1.8.0_252) you have used to run this analysis is deprecated and we will stop accepting it from October 2020. Please update to at least Java 11.
Read more here

[codecov-commenter]

Codecov Report

Merging #1887 into master will decrease coverage by 0.00%.
The diff coverage is 100.00%.

@@             Coverage Diff              @@
##             master    #1887      +/-   ##
============================================
- Coverage     76.21%   76.21%   -0.01%     
  Complexity      187      187              
============================================
  Files          1076     1076              
  Lines         32564    32568       +4     
  Branches       2569     2569              
============================================
+ Hits          24818    24821       +3     
- Misses         6486     6488       +2     
+ Partials       1260     1259       -1     

Flag	Coverage Δ	Complexity Δ
#unittests	76.21% <100.00%> (-0.01%)	187.00 <0.00> (ø)

Impacted Files	Coverage Δ	Complexity Δ
...k/http/nio/netty/internal/ChannelAttributeKey.java	100.00% <100.00%> (ø)	0.00 <0.00> (ø)
.../nio/netty/internal/Http1TunnelConnectionPool.java	98.24% <100.00%> (ø)	0.00 <0.00> (ø)
...ttp/nio/netty/internal/ReleaseOnceChannelPool.java	80.00% <100.00%> (ø)	0.00 <0.00> (ø)
...ty/internal/http2/Http2MultiplexedChannelPool.java	76.75% <100.00%> (ø)	0.00 <0.00> (ø)
...ssdk/http/nio/netty/internal/utils/NettyUtils.java	37.50% <100.00%> (+4.16%)	0.00 <0.00> (ø)
...ernal/utils/OrderedWriteChannelHandlerContext.java	60.86% <100.00%> (ø)	0.00 <0.00> (ø)
.../awssdk/http/apache/internal/net/SdkSslSocket.java	50.00% <0.00%> (-9.10%)	0.00% <0.00%> (ø%)
...ware/amazon/awssdk/utils/cache/CachedSupplier.java	90.24% <0.00%> (+2.43%)	0.00% <0.00%> (ø%)

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update d155ac8...96e67ec. Read the comment docs.