diff src/share/vm/gc_implementation/g1/g1StringDedupThread.cpp @ 17764:595c0f60d50d

8029075: String deduplication in G1 Summary: Implementation of JEP 192, http://openjdk.java.net/jeps/192 Reviewed-by: brutisso, tschatzl, coleenp
author pliden
date Tue, 18 Mar 2014 19:07:22 +0100
parents
children 1772223a25a2
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/gc_implementation/g1/g1StringDedupThread.cpp	Tue Mar 18 19:07:22 2014 +0100
@@ -0,0 +1,124 @@
+/*
+ * Copyright (c) 2014, 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.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "gc_implementation/g1/g1Log.hpp"
+#include "gc_implementation/g1/g1StringDedup.hpp"
+#include "gc_implementation/g1/g1StringDedupTable.hpp"
+#include "gc_implementation/g1/g1StringDedupThread.hpp"
+#include "gc_implementation/g1/g1StringDedupQueue.hpp"
+
+G1StringDedupThread* G1StringDedupThread::_thread = NULL;
+
+G1StringDedupThread::G1StringDedupThread() :
+  ConcurrentGCThread() {
+  set_name("String Deduplication Thread");
+  create_and_start();
+}
+
+G1StringDedupThread::~G1StringDedupThread() {
+  ShouldNotReachHere();
+}
+
+void G1StringDedupThread::create() {
+  assert(G1StringDedup::is_enabled(), "String deduplication not enabled");
+  assert(_thread == NULL, "One string deduplication thread allowed");
+  _thread = new G1StringDedupThread();
+}
+
+G1StringDedupThread* G1StringDedupThread::thread() {
+  assert(G1StringDedup::is_enabled(), "String deduplication not enabled");
+  assert(_thread != NULL, "String deduplication thread not created");
+  return _thread;
+}
+
+void G1StringDedupThread::print_on(outputStream* st) const {
+  st->print("\"%s\" ", name());
+  Thread::print_on(st);
+  st->cr();
+}
+
+void G1StringDedupThread::run() {
+  G1StringDedupStat total_stat;
+
+  initialize_in_thread();
+  wait_for_universe_init();
+
+  // Main loop
+  for (;;) {
+    G1StringDedupStat stat;
+
+    stat.mark_idle();
+
+    // Wait for the queue to become non-empty
+    G1StringDedupQueue::wait();
+
+    // Include this thread in safepoints
+    stsJoin();
+
+    stat.mark_exec();
+
+    // Process the queue
+    for (;;) {
+      oop java_string = G1StringDedupQueue::pop();
+      if (java_string == NULL) {
+        break;
+      }
+
+      G1StringDedupTable::deduplicate(java_string, stat);
+
+      // Safepoint this thread if needed
+      if (stsShouldYield()) {
+        stat.mark_block();
+        stsYield(NULL);
+        stat.mark_unblock();
+      }
+    }
+
+    G1StringDedupTable::trim_entry_cache();
+
+    stat.mark_done();
+
+    // Print statistics
+    total_stat.add(stat);
+    print(gclog_or_tty, stat, total_stat);
+
+    // Exclude this thread from safepoints
+    stsLeave();
+  }
+
+  ShouldNotReachHere();
+}
+
+void G1StringDedupThread::print(outputStream* st, const G1StringDedupStat& last_stat, const G1StringDedupStat& total_stat) {
+  if (G1Log::fine() || PrintStringDeduplicationStatistics) {
+    G1StringDedupStat::print_summary(st, last_stat, total_stat);
+    if (PrintStringDeduplicationStatistics) {
+      G1StringDedupStat::print_statistics(st, last_stat, false);
+      G1StringDedupStat::print_statistics(st, total_stat, true);
+      G1StringDedupTable::print_statistics(st);
+      G1StringDedupQueue::print_statistics(st);
+    }
+  }
+}