diff src/share/vm/classfile/symbolTable.hpp @ 0:a61af66fc99e

Initial load
author duke
date Sat, 01 Dec 2007 00:00:00 +0000
parents
children c89f86385056
line wrap: on
line diff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/classfile/symbolTable.hpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,213 @@
+/*
+ * Copyright 1997-2006 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+// The symbol table holds all symbolOops and corresponding interned strings.
+// symbolOops and literal strings should be canonicalized.
+//
+// The interned strings are created lazily.
+//
+// It is implemented as an open hash table with a fixed number of buckets.
+//
+// %note:
+//  - symbolTableEntrys are allocated in blocks to reduce the space overhead.
+
+class BoolObjectClosure;
+
+
+class SymbolTable : public Hashtable {
+  friend class VMStructs;
+
+private:
+  // The symbol table
+  static SymbolTable* _the_table;
+
+  // Adding elements
+  symbolOop basic_add(int index, u1* name, int len,
+                      unsigned int hashValue, TRAPS);
+  bool basic_add(constantPoolHandle cp, int names_count,
+                 const char** names, int* lengths, int* cp_indices,
+                 unsigned int* hashValues, TRAPS);
+
+  // Table size
+  enum {
+    symbol_table_size = 20011
+  };
+
+  symbolOop lookup(int index, const char* name, int len, unsigned int hash);
+
+  SymbolTable()
+    : Hashtable(symbol_table_size, sizeof (HashtableEntry)) {}
+
+  SymbolTable(HashtableBucket* t, int number_of_entries)
+    : Hashtable(symbol_table_size, sizeof (HashtableEntry), t,
+                number_of_entries) {}
+
+
+public:
+  enum {
+    symbol_alloc_batch_size = 8
+  };
+
+  // The symbol table
+  static SymbolTable* the_table() { return _the_table; }
+
+  static void create_table() {
+    assert(_the_table == NULL, "One symbol table allowed.");
+    _the_table = new SymbolTable();
+  }
+
+  static void create_table(HashtableBucket* t, int length,
+                           int number_of_entries) {
+    assert(_the_table == NULL, "One symbol table allowed.");
+    assert(length == symbol_table_size * sizeof(HashtableBucket),
+           "bad shared symbol size.");
+    _the_table = new SymbolTable(t, number_of_entries);
+  }
+
+  static symbolOop lookup(const char* name, int len, TRAPS);
+  // lookup only, won't add. Also calculate hash.
+  static symbolOop lookup_only(const char* name, int len, unsigned int& hash);
+  // Only copy to C string to be added if lookup failed.
+  static symbolOop lookup(symbolHandle sym, int begin, int end, TRAPS);
+
+  static void add(constantPoolHandle cp, int names_count,
+                  const char** names, int* lengths, int* cp_indices,
+                  unsigned int* hashValues, TRAPS);
+
+  // GC support
+  //   Delete pointers to otherwise-unreachable objects.
+  static void unlink(BoolObjectClosure* cl) {
+    the_table()->Hashtable::unlink(cl);
+  }
+
+  // Invoke "f->do_oop" on the locations of all oops in the table.
+  static void oops_do(OopClosure* f) {
+    the_table()->Hashtable::oops_do(f);
+  }
+
+  // Symbol lookup
+  static symbolOop lookup(int index, const char* name, int len, TRAPS);
+
+  // Needed for preloading classes in signatures when compiling.
+  // Returns the symbol is already present in symbol table, otherwise
+  // NULL.  NO ALLOCATION IS GUARANTEED!
+  static symbolOop probe(const char* name, int len);
+
+  // Histogram
+  static void print_histogram()     PRODUCT_RETURN;
+
+  // Debugging
+  static void verify();
+
+  // Sharing
+  static void copy_buckets(char** top, char*end) {
+    the_table()->Hashtable::copy_buckets(top, end);
+  }
+  static void copy_table(char** top, char*end) {
+    the_table()->Hashtable::copy_table(top, end);
+  }
+  static void reverse(void* boundary = NULL) {
+    ((Hashtable*)the_table())->reverse(boundary);
+  }
+};
+
+
+class StringTable : public Hashtable {
+  friend class VMStructs;
+
+private:
+  // The string table
+  static StringTable* _the_table;
+
+  static oop intern(Handle string_or_null, jchar* chars, int length, TRAPS);
+  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(string_table_size, sizeof (HashtableEntry)) {}
+
+  StringTable(HashtableBucket* t, int number_of_entries)
+    : Hashtable(string_table_size, sizeof (HashtableEntry), t,
+                number_of_entries) {}
+
+public:
+  // The string table
+  static StringTable* the_table() { return _the_table; }
+
+  static void create_table() {
+    assert(_the_table == NULL, "One string table allowed.");
+    _the_table = new StringTable();
+  }
+
+  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),
+           "bad shared string size.");
+    _the_table = new StringTable(t, number_of_entries);
+  }
+
+
+  static int hash_string(jchar* s, int len);
+
+
+  // GC support
+  //   Delete pointers to otherwise-unreachable objects.
+  static void unlink(BoolObjectClosure* cl) {
+    the_table()->Hashtable::unlink(cl);
+  }
+
+  // Invoke "f->do_oop" on the locations of all oops in the table.
+  static void oops_do(OopClosure* f) {
+    the_table()->Hashtable::oops_do(f);
+  }
+
+  // Probing
+  static oop lookup(symbolOop symbol);
+
+  // Interning
+  static oop intern(symbolOop symbol, TRAPS);
+  static oop intern(oop string, TRAPS);
+  static oop intern(const char *utf8_string, TRAPS);
+
+  // Debugging
+  static void verify();
+
+  // Sharing
+  static void copy_buckets(char** top, char*end) {
+    the_table()->Hashtable::copy_buckets(top, end);
+  }
+  static void copy_table(char** top, char*end) {
+    the_table()->Hashtable::copy_table(top, end);
+  }
+  static void reverse() {
+    ((BasicHashtable*)the_table())->reverse();
+  }
+};