6962930: make the string table size configurable

Reviewed-by: never, phh, stefank, kamg, dholmes, coleenp

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

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

src/share/vm/classfile/symbolTable.hpp

@@ -216,17 +216,13 @@ private:
   oop basic_add(int index, Handle string_or_null, jchar* name, int len,
                 unsigned int hashValue, TRAPS);
 
-  // Table size
-  enum {
-    string_table_size = 1009
-  };
-
   oop lookup(int index, jchar* chars, int length, unsigned int hashValue);
 
-  StringTable() : Hashtable<oop>(string_table_size, sizeof (HashtableEntry<oop>)) {}
+  StringTable() : Hashtable<oop>((int)StringTableSize,
+                                 sizeof (HashtableEntry<oop>)) {}
 
   StringTable(HashtableBucket* t, int number_of_entries)
-    : Hashtable<oop>(string_table_size, sizeof (HashtableEntry<oop>), t,
+    : Hashtable<oop>((int)StringTableSize, sizeof (HashtableEntry<oop>), t,
                      number_of_entries) {}
 
 public:
@@ -241,7 +237,7 @@ public:
   static void create_table(HashtableBucket* t, int length,
                            int number_of_entries) {
     assert(_the_table == NULL, "One string table allowed.");
-    assert(length == string_table_size * sizeof(HashtableBucket),
+    assert((size_t)length == StringTableSize * sizeof(HashtableBucket),
            "bad shared string size.");
     _the_table = new StringTable(t, number_of_entries);
   }

src/share/vm/runtime/arguments.cpp

@@ -2819,14 +2819,30 @@ jint Arguments::parse_options_environment_variable(const char* name, SysClassPat
 }
 
 void Arguments::set_shared_spaces_flags() {
+  const bool must_share = DumpSharedSpaces || RequireSharedSpaces;
+  const bool might_share = must_share || UseSharedSpaces;
+
+  // The string table is part of the shared archive so the size must match.
+  if (!FLAG_IS_DEFAULT(StringTableSize)) {
+    // Disable sharing.
+    if (must_share) {
+      warning("disabling shared archive %s because of non-default "
+              "StringTableSize", DumpSharedSpaces ? "creation" : "use");
+    }
+    if (might_share) {
+      FLAG_SET_DEFAULT(DumpSharedSpaces, false);
+      FLAG_SET_DEFAULT(RequireSharedSpaces, false);
+      FLAG_SET_DEFAULT(UseSharedSpaces, false);
+    }
+    return;
+  }
+
   // Check whether class data sharing settings conflict with GC, compressed oops
   // or page size, and fix them up.  Explicit sharing options override other
   // settings.
   const bool cannot_share = UseConcMarkSweepGC || CMSIncrementalMode ||
     UseG1GC || UseParNewGC || UseParallelGC || UseParallelOldGC ||
     UseCompressedOops || UseLargePages && FLAG_IS_CMDLINE(UseLargePages);
-  const bool must_share = DumpSharedSpaces || RequireSharedSpaces;
-  const bool might_share = must_share || UseSharedSpaces;
   if (cannot_share) {
     if (must_share) {
         warning("selecting serial gc and disabling large pages %s"

src/share/vm/runtime/globals.hpp

@@ -3756,6 +3756,9 @@ class CommandLineFlags {
   diagnostic(bool, PrintDTraceDOF, false,                                   \
              "Print the DTrace DOF passed to the system for JSDT probes")   \
                                                                             \
+  product(uintx, StringTableSize, 1009,                                     \
+          "Number of buckets in the interned String table")                 \
+                                                                            \
   product(bool, UseVMInterruptibleIO, false,                                \
           "(Unstable, Solaris-specific) Thread interrupt before or with "   \
           "EINTR for I/O operations results in OS_INTRPT. The default value"\

src/share/vm/runtime/vmStructs.cpp

@@ -1553,12 +1553,6 @@ static inline uint64_t cast_uint64_t(size_t x)
                                                                           \
   declare_constant(SymbolTable::symbol_table_size)                        \
                                                                           \
-  /***************/                                                       \
-  /* StringTable */                                                       \
-  /***************/                                                       \
-                                                                          \
-  declare_constant(StringTable::string_table_size)                        \
-                                                                          \
   /********************/                                                  \
   /* SystemDictionary */                                                  \
   /********************/                                                  \