src/java.base/share/classes/jdk/internal/misc/VM.java

rev 52426 : 8185496: Improve performance of system properties initialization in initPhase1
8213424: VersionProps duplicate and skipped initialization

@@ -197,22 +197,21 @@
 
         // Set the maximum amount of direct memory.  This value is controlled
         // by the vm option -XX:MaxDirectMemorySize=<size>.
         // The maximum amount of allocatable direct buffer memory (in bytes)
         // from the system property sun.nio.MaxDirectMemorySize set by the VM.
+        // If not set or set to -1, the max memory will be used
         // The system property will be removed.
         String s = (String)props.remove("sun.nio.MaxDirectMemorySize");
-        if (s != null) {
-            if (s.equals("-1")) {
+        if (s == null || s.isEmpty() || s.equals("-1")) {
                 // -XX:MaxDirectMemorySize not given, take default
                 directMemory = Runtime.getRuntime().maxMemory();
             } else {
                 long l = Long.parseLong(s);
                 if (l > -1)
                     directMemory = l;
             }
-        }
 
         // Check if direct buffers should be page aligned
         s = (String)props.remove("sun.nio.PageAlignDirectMemory");
         if ("true".equals(s))
             pageAlignDirectMemory = true;