src/share/vm/memory/metaspaceShared.cpp

*** 814,823 ****
--- 814,824 ----
          class_count++;
        } else {
          //tty->print_cr("Preload failed: %s", class_name);
        }
      }
+     fclose(file);
    } else {
      char errmsg[JVM_MAXPATHLEN];
      os::lasterror(errmsg, JVM_MAXPATHLEN);
      tty->print_cr("Loading classlist failed: %s", errmsg);
      exit(1);
*** 1084,1088 ****
--- 1085,1135 ----
        return false;
      }
    }
    return true;
  }
+ 
+ int MetaspaceShared::count_class(const char* classlist_file) {
+   if (classlist_file == NULL) {
+     return 0;
+   }
+   char class_name[256];
+   int class_count = 0;
+   FILE* file = fopen(classlist_file, "r");
+   if (file != NULL) {
+     while ((fgets(class_name, sizeof class_name, file)) != NULL) {
+       if (*class_name == '#') { // comment
+         continue;
+       }
+       class_count++;
+     }
+     fclose(file);
+   } else {
+     char errmsg[JVM_MAXPATHLEN];
+     os::lasterror(errmsg, JVM_MAXPATHLEN);
+     tty->print_cr("Loading classlist failed: %s", errmsg);
+     exit(1);
+   }
+ 
+   return class_count;
+ }
+ 
+ // the sizes are good for typical large applications that have a lot of shared
+ // classes
+ void MetaspaceShared::estimate_regions_size() {
+   int class_count = count_class(SharedClassListFile);
+   class_count += count_class(ExtraSharedClassListFile);
+ 
+   if (class_count > LargeThresholdClassCount) {
+     if (class_count < HugeThresholdClassCount) {
+       SET_ESTIMATED_SIZE(Large, ReadOnly);
+       SET_ESTIMATED_SIZE(Large, ReadWrite);
+       SET_ESTIMATED_SIZE(Large, MiscData);
+       SET_ESTIMATED_SIZE(Large, MiscCode);
+     } else {
+       SET_ESTIMATED_SIZE(Huge,  ReadOnly);
+       SET_ESTIMATED_SIZE(Huge,  ReadWrite);
+       SET_ESTIMATED_SIZE(Huge,  MiscData);
+       SET_ESTIMATED_SIZE(Huge,  MiscCode);
+     }
+   }
+ }