Allow to generate a jmh uber jar to run benchmarks easily from cmdlin…

…e with different arguments. (netty#8264)

Motivation:

It is sometimes useful to be able to run benchmarks easily from the commandline and passs different arguments / options here. We should support this.

Modifications:

Add the benchmark-jar profile which allows to generate such an "uber-jar" that can be used directly to run benchmarks as documented at http://openjdk.java.net/projects/code-tools/jmh/.

Result:

More flexible way to run benchmarks.

microbench/pom.xml

@@ -61,6 +61,48 @@
         </plugins>
       </build>
     </profile>
+    <profile>
+      <id>benchmark-jar</id>
+      <build>
+        <plugins>
+          <plugin>
+            <groupId>org.apache.maven.plugins</groupId>
+            <artifactId>maven-shade-plugin</artifactId>
+            <version>2.2</version>
+            <executions>
+              <execution>
+                <phase>package</phase>
+                <goals>
+                  <goal>shade</goal>
+                </goals>
+                <configuration>
+                  <finalName>microbenchmarks</finalName>
+                  <transformers>
+                    <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
+                      <mainClass>org.openjdk.jmh.Main</mainClass>
+                    </transformer>
+                  </transformers>
+                  <filters>
+                    <filter>
+                      <!--
+                          Shading signed JARs will fail without this.
+                          http://stackoverflow.com/questions/999489/invalid-signature-file-when-attempting-to-run-a-jar
+                      -->
+                      <artifact>*:*</artifact>
+                      <excludes>
+                        <exclude>META-INF/*.SF</exclude>
+                        <exclude>META-INF/*.DSA</exclude>
+                        <exclude>META-INF/*.RSA</exclude>
+                      </excludes>
+                    </filter>
+                  </filters>
+                </configuration>
+              </execution>
+            </executions>
+          </plugin>
+        </plugins>
+      </build>
+    </profile>
   </profiles>
 
   <dependencies>