8019375: Internal symbol table size should be tunable

Reviewed-by: coleenp, kamg

hotspot/agent/src/share/classes/sun/jvm/hotspot/memory/SymbolTable.java

@@ -44,12 +44,10 @@ public class SymbolTable extends sun.jvm.hotspot.utilities.Hashtable {
   private static synchronized void initialize(TypeDataBase db) {
     Type type = db.lookupType("SymbolTable");
     theTableField  = type.getAddressField("_the_table");
-    symbolTableSize = db.lookupIntConstant("SymbolTable::symbol_table_size").intValue();
   }
 
   // Fields
   private static AddressField theTableField;
-  private static int symbolTableSize;
 
   // Accessors
   public static SymbolTable getTheTable() {
@@ -57,10 +55,6 @@ public class SymbolTable extends sun.jvm.hotspot.utilities.Hashtable {
     return (SymbolTable) VMObjectFactory.newObject(SymbolTable.class, tmp);
   }
 
-  public static int getSymbolTableSize() {
-    return symbolTableSize;
-  }
-
   public SymbolTable(Address addr) {
     super(addr);
   }

hotspot/src/share/vm/classfile/symbolTable.hpp

@@ -107,18 +107,13 @@ private:
     add(loader_data, cp, names_count, name, lengths, cp_indices, hashValues, THREAD);
   }
 
-  // Table size
-  enum {
-    symbol_table_size = 20011
-  };
-
   Symbol* lookup(int index, const char* name, int len, unsigned int hash);
 
   SymbolTable()
-    : Hashtable<Symbol*, mtSymbol>(symbol_table_size, sizeof (HashtableEntry<Symbol*, mtSymbol>)) {}
+    : Hashtable<Symbol*, mtSymbol>(SymbolTableSize, sizeof (HashtableEntry<Symbol*, mtSymbol>)) {}
 
   SymbolTable(HashtableBucket<mtSymbol>* t, int number_of_entries)
-    : Hashtable<Symbol*, mtSymbol>(symbol_table_size, sizeof (HashtableEntry<Symbol*, mtSymbol>), t,
+    : Hashtable<Symbol*, mtSymbol>(SymbolTableSize, sizeof (HashtableEntry<Symbol*, mtSymbol>), t,
                 number_of_entries) {}
 
   // Arena for permanent symbols (null class loader) that are never unloaded
@@ -136,6 +131,9 @@ public:
   // The symbol table
   static SymbolTable* the_table() { return _the_table; }
 
+  // Size of one bucket in the string table.  Used when checking for rollover.
+  static uint bucket_size() { return sizeof(HashtableBucket<mtSymbol>); }
+
   static void create_table() {
     assert(_the_table == NULL, "One symbol table allowed.");
     _the_table = new SymbolTable();
@@ -145,8 +143,11 @@ public:
   static void create_table(HashtableBucket<mtSymbol>* t, int length,
                            int number_of_entries) {
     assert(_the_table == NULL, "One symbol table allowed.");
-    assert(length == symbol_table_size * sizeof(HashtableBucket<mtSymbol>),
+
-           "bad shared symbol size.");
+    // If CDS archive used a different symbol table size, use that size instead
+    // which is better than giving an error.
+    SymbolTableSize = length/bucket_size();
+
     _the_table = new SymbolTable(t, number_of_entries);
     // if CDS give symbol table a default arena size since most symbols
     // are already allocated in the shared misc section.

hotspot/src/share/vm/runtime/arguments.cpp

@@ -2045,6 +2045,9 @@ bool Arguments::check_vm_args_consistency() {
   status = status && verify_interval(StringTableSize, minimumStringTableSize,
     (max_uintx / StringTable::bucket_size()), "StringTable size");
 
+  status = status && verify_interval(SymbolTableSize, minimumSymbolTableSize,
+    (max_uintx / SymbolTable::bucket_size()), "SymbolTable size");
+
   if (MinHeapFreeRatio > MaxHeapFreeRatio) {
     jio_fprintf(defaultStream::error_stream(),
                 "MinHeapFreeRatio (" UINTX_FORMAT ") must be less than or "

hotspot/src/share/vm/runtime/globals.hpp

@@ -3727,6 +3727,9 @@ class CommandLineFlags {
   product(uintx, StringTableSize, defaultStringTableSize,                   \
           "Number of buckets in the interned String table")                 \
                                                                             \
+  experimental(uintx, SymbolTableSize, defaultSymbolTableSize,              \
+          "Number of buckets in the JVM internal Symbol table")             \
+                                                                            \
   develop(bool, TraceDefaultMethods, false,                                 \
           "Trace the default method processing steps")                      \
                                                                             \

hotspot/src/share/vm/runtime/vmStructs.cpp

@@ -27,7 +27,6 @@
 #include "classfile/javaClasses.hpp"
 #include "classfile/loaderConstraints.hpp"
 #include "classfile/placeholders.hpp"
-#include "classfile/symbolTable.hpp"
 #include "classfile/systemDictionary.hpp"
 #include "ci/ciField.hpp"
 #include "ci/ciInstance.hpp"
@@ -2249,12 +2248,6 @@ typedef BinaryTreeDictionary<Metablock, FreeList> MetablockTreeDictionary;
   declare_preprocessor_constant("PERFDATA_BIG_ENDIAN", PERFDATA_BIG_ENDIAN)       \
   declare_preprocessor_constant("PERFDATA_LITTLE_ENDIAN", PERFDATA_LITTLE_ENDIAN) \
                                                                           \
-  /***************/                                                       \
-  /* SymbolTable */                                                       \
-  /***************/                                                       \
-                                                                          \
-  declare_constant(SymbolTable::symbol_table_size)                        \
-                                                                          \
   /***********************************/                                   \
   /* LoaderConstraintTable constants */                                   \
   /***********************************/                                   \

hotspot/src/share/vm/utilities/globalDefinitions.hpp

@@ -333,6 +333,9 @@ const int max_method_code_size = 64*K - 1;  // JVM spec, 2nd ed. section 4.8.1 (
 const int defaultStringTableSize = NOT_LP64(1009) LP64_ONLY(60013);
 const int minimumStringTableSize=1009;
 
+const int defaultSymbolTableSize = 20011;
+const int minimumSymbolTableSize = 1009;
+
 
 //----------------------------------------------------------------------------------------------------
 // HotSwap - for JVMTI   aka Class File Replacement and PopFrame