src/jdk.internal.vm.ci/share/classes/jdk.vm.ci.hotspot/src/jdk/vm/ci/hotspot/HotSpotNmethod.java

*** 28,44 ****
  import jdk.vm.ci.meta.JavaKind;
  import jdk.vm.ci.meta.JavaType;
  import jdk.vm.ci.meta.ResolvedJavaMethod;
  
  /**
!  * Implementation of {@link InstalledCode} for code installed as an nmethod. The nmethod stores a
!  * weak reference to an instance of this class. This is necessary to keep the nmethod from being
!  * unloaded while the associated {@link HotSpotNmethod} instance is alive.
!  * <p>
!  * Note that there is no (current) way for the reference from an nmethod to a {@link HotSpotNmethod}
!  * instance to be anything but weak. This is due to the fact that HotSpot does not treat nmethods as
!  * strong GC roots.
   */
  public class HotSpotNmethod extends HotSpotInstalledCode {
  
      /**
       * This (indirect) Method* reference is safe since class redefinition preserves all methods
--- 28,41 ----
  import jdk.vm.ci.meta.JavaKind;
  import jdk.vm.ci.meta.JavaType;
  import jdk.vm.ci.meta.ResolvedJavaMethod;
  
  /**
!  * Implementation of {@link InstalledCode} for code installed as an nmethod.
!  *
!  * When a {@link HotSpotNmethod} dies, it triggers unloading of the nmethod unless
!  * {@link #isDefault() == true}.
   */
  public class HotSpotNmethod extends HotSpotInstalledCode {
  
      /**
       * This (indirect) Method* reference is safe since class redefinition preserves all methods
*** 52,61 ****
--- 49,63 ----
          super(name);
          this.method = method;
          this.isDefault = isDefault;
      }
  
+     /**
+      * Determines if the nmethod associated with this object is the compiled entry point for
+      * {@link #getMethod()}. If {@code false}, then the nmethod is unloaded when the VM determines
+      * this object has died.
+      */
      public boolean isDefault() {
          return isDefault;
      }
  
      public ResolvedJavaMethod getMethod() {