YARN-9398. Fixed javadoc errors for FPGA related java files.

            Contributed by Peter Bacsko

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/resourceplugin/fpga/AbstractFpgaVendorPlugin.java

@@ -42,11 +42,16 @@ public interface AbstractFpgaVendorPlugin {
 
   /**
    * Check vendor's toolchain and required environment
+   * @param conf Hadoop configuration
+   * @return true if the initialization was successful
    * */
   boolean initPlugin(Configuration conf);
 
   /**
    * Diagnose the devices using vendor toolchain but no need to parse device information
+   *
+   * @param timeout timeout in milliseconds
+   * @return true if the diagnostics was successful
    * */
   boolean diagnose(int timeout);
 
@@ -60,6 +65,8 @@ public interface AbstractFpgaVendorPlugin {
   /**
    * Since all vendor plugins share a {@link org.apache.hadoop.yarn.server.nodemanager.containermanager.linux.resources.fpga.FpgaResourceAllocator}
    * which distinguish FPGA devices by type. Vendor plugin must report this.
+   *
+   * @return the type of FPGA plugin represented as a string
    * */
   String getFpgaType();
 

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/resourceplugin/fpga/FpgaDiscoverer.java

@@ -114,8 +114,11 @@ public class FpgaDiscoverer {
   }
 
   /**
-   * get avialable devices minor numbers from toolchain or static configuration
-   * */
+   * Get available devices minor numbers from toolchain or static configuration.
+   *
+   * @return the list of FPGA devices
+   * @throws ResourceHandlerException if there's any error during discovery
+   **/
   public List<FpgaResourceAllocator.FpgaDevice> discover()
       throws ResourceHandlerException {
     List<FpgaResourceAllocator.FpgaDevice> list;

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/resourceplugin/fpga/IntelFpgaOpenclPlugin.java

@@ -153,7 +153,7 @@ public class IntelFpgaOpenclPlugin implements AbstractFpgaVendorPlugin {
   }
 
   /**
-   *  Helper class to run aocl diagnose & determine major/minor numbers.
+   *  Helper class to run aocl diagnose & determine major/minor numbers.
    */
   public static class InnerShellExecutor {