--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/classfile/stringTable.hpp Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,177 @@
+/*
+ * Copyright (c) 1997, 2017, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_VM_CLASSFILE_STRINGTABLE_HPP
+#define SHARE_VM_CLASSFILE_STRINGTABLE_HPP
+
+#include "memory/allocation.inline.hpp"
+#include "utilities/hashtable.hpp"
+
+template <class T, class N> class CompactHashtable;
+class CompactStringTableWriter;
+class FileMapInfo;
+class SerializeClosure;
+
+class StringTable : public RehashableHashtable<oop, mtSymbol> {
+ friend class VMStructs;
+ friend class Symbol;
+
+private:
+ // The string table
+ static StringTable* _the_table;
+
+ // Shared string table
+ static CompactHashtable<oop, char> _shared_table;
+ static bool _shared_string_mapped;
+
+ // Set if one bucket is out of balance due to hash algorithm deficiency
+ static bool _needs_rehashing;
+
+ // Claimed high water mark for parallel chunked scanning
+ static volatile int _parallel_claimed_idx;
+
+ 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);
+
+ oop lookup_in_main_table(int index, jchar* chars, int length, unsigned int hashValue);
+ static oop lookup_shared(jchar* name, int len, unsigned int hash);
+
+ // Apply the give oop closure to the entries to the buckets
+ // in the range [start_idx, end_idx).
+ static void buckets_oops_do(OopClosure* f, int start_idx, int end_idx);
+
+ typedef StringTable::BucketUnlinkContext BucketUnlinkContext;
+ // Unlink or apply the give oop closure to the entries to the buckets
+ // in the range [start_idx, end_idx). Unlinked bucket entries are collected in the given
+ // context to be freed later.
+ // This allows multiple threads to work on the table at once.
+ static void buckets_unlink_or_oops_do(BoolObjectClosure* is_alive, OopClosure* f, int start_idx, int end_idx, BucketUnlinkContext* context);
+
+ // Hashing algorithm, used as the hash value used by the
+ // StringTable for bucket selection and comparison (stored in the
+ // HashtableEntry structures). This is used in the String.intern() method.
+ static unsigned int hash_string(const jchar* s, int len);
+ static unsigned int hash_string(oop string);
+ static unsigned int alt_hash_string(const jchar* s, int len);
+
+ StringTable() : RehashableHashtable<oop, mtSymbol>((int)StringTableSize,
+ sizeof (HashtableEntry<oop, mtSymbol>)) {}
+
+ StringTable(HashtableBucket<mtSymbol>* t, int number_of_entries)
+ : RehashableHashtable<oop, mtSymbol>((int)StringTableSize, sizeof (HashtableEntry<oop, mtSymbol>), t,
+ number_of_entries) {}
+public:
+ // The string table
+ static StringTable* 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 string table allowed.");
+ _the_table = new StringTable();
+ }
+
+ // GC support
+ // Delete pointers to otherwise-unreachable objects.
+ static void unlink_or_oops_do(BoolObjectClosure* cl, OopClosure* f) {
+ int processed = 0;
+ int removed = 0;
+ unlink_or_oops_do(cl, f, &processed, &removed);
+ }
+ static void unlink(BoolObjectClosure* cl) {
+ int processed = 0;
+ int removed = 0;
+ unlink_or_oops_do(cl, NULL, &processed, &removed);
+ }
+ static void unlink_or_oops_do(BoolObjectClosure* cl, OopClosure* f, int* processed, int* removed);
+ static void unlink(BoolObjectClosure* cl, int* processed, int* removed) {
+ unlink_or_oops_do(cl, NULL, processed, removed);
+ }
+ // Serially invoke "f->do_oop" on the locations of all oops in the table.
+ static void oops_do(OopClosure* f);
+
+ // Possibly parallel versions of the above
+ static void possibly_parallel_unlink_or_oops_do(BoolObjectClosure* cl, OopClosure* f, int* processed, int* removed);
+ static void possibly_parallel_unlink(BoolObjectClosure* cl, int* processed, int* removed) {
+ possibly_parallel_unlink_or_oops_do(cl, NULL, processed, removed);
+ }
+ static void possibly_parallel_oops_do(OopClosure* f);
+
+ // Internal test.
+ static void test_alt_hash() PRODUCT_RETURN;
+
+ // Probing
+ static oop lookup(Symbol* symbol);
+ static oop lookup(jchar* chars, int length);
+
+ // Interning
+ static oop intern(Symbol* symbol, TRAPS);
+ static oop intern(oop string, TRAPS);
+ static oop intern(const char *utf8_string, TRAPS);
+
+ // Debugging
+ static void verify();
+ static void dump(outputStream* st, bool verbose=false);
+
+ enum VerifyMesgModes {
+ _verify_quietly = 0,
+ _verify_with_mesgs = 1
+ };
+
+ enum VerifyRetTypes {
+ _verify_pass = 0,
+ _verify_fail_continue = 1,
+ _verify_fail_done = 2
+ };
+
+ static VerifyRetTypes compare_entries(int bkt1, int e_cnt1,
+ HashtableEntry<oop, mtSymbol>* e_ptr1,
+ int bkt2, int e_cnt2,
+ HashtableEntry<oop, mtSymbol>* e_ptr2);
+ static VerifyRetTypes verify_entry(int bkt, int e_cnt,
+ HashtableEntry<oop, mtSymbol>* e_ptr,
+ VerifyMesgModes mesg_mode);
+ static int verify_and_compare_entries();
+
+ // Sharing
+ static void set_shared_string_mapped() { _shared_string_mapped = true; }
+ static bool shared_string_mapped() { return _shared_string_mapped; }
+ static void shared_oops_do(OopClosure* f) NOT_CDS_JAVA_HEAP_RETURN;
+ static bool copy_shared_string(GrowableArray<MemRegion> *string_space,
+ CompactStringTableWriter* ch_table) NOT_CDS_JAVA_HEAP_RETURN_(false);
+ static oop create_archived_string(oop s, Thread* THREAD) NOT_CDS_JAVA_HEAP_RETURN_(NULL);
+ static void write_to_archive(GrowableArray<MemRegion> *string_space) NOT_CDS_JAVA_HEAP_RETURN;
+ static void serialize(SerializeClosure* soc) NOT_CDS_JAVA_HEAP_RETURN;
+
+ // Rehash the symbol table if it gets out of balance
+ static void rehash_table();
+ static bool needs_rehashing() { return _needs_rehashing; }
+
+ // Parallel chunked scanning
+ static void clear_parallel_claimed_index() { _parallel_claimed_idx = 0; }
+ static int parallel_claimed_index() { return _parallel_claimed_idx; }
+};
+#endif // SHARE_VM_CLASSFILE_STRINGTABLE_HPP