Override and javadoc

Author: roberttoyonaga

sdk/src/org.graalvm.nativeimage/src/org/graalvm/nativeimage/impl/UnmanagedMemorySupport.java

@@ -46,14 +46,18 @@
 /** Implemented by operating-system specific code. */
 public interface UnmanagedMemorySupport {
     <T extends PointerBase> T malloc(UnsignedWord size);
+
     <T extends PointerBase> T malloc(UnsignedWord size, int flag);
 
     <T extends PointerBase> T calloc(UnsignedWord size);
+
     <T extends PointerBase> T calloc(UnsignedWord size, int flag);
 
     <T extends PointerBase> T realloc(T ptr, UnsignedWord size);
+
     <T extends PointerBase> T realloc(T ptr, UnsignedWord size, int flag);
 
     void free(PointerBase ptr);
+
     void untrackedFree(PointerBase ptr);
 }

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/nmt/PreInitTable.java

@@ -59,6 +59,7 @@ protected boolean isEqual(UninterruptibleEntry a, UninterruptibleEntry b) {
         return a.getHash() == b.getHash();
     }
 
+    /** This override is necessary to use LibC directly. */
     @Override
     @Uninterruptible(reason = "Called from uninterruptible code.", mayBeInlined = true)
     protected UninterruptibleEntry copyToHeap(UninterruptibleEntry valueOnStack) {
@@ -72,6 +73,11 @@ protected UninterruptibleEntry copyToHeap(UninterruptibleEntry valueOnStack) {
         return WordFactory.nullPointer();
     }
 
+    /**
+     * Since these native memory hashtable nodes don't have headers, this is necessary to avoid
+     * re-entering NMT code. Use LibC directly.
+     */
+    @Override
     @Uninterruptible(reason = "Called from uninterruptible code.", mayBeInlined = true)
     protected void free(UninterruptibleEntry entry) {
         size--;