Sat, 19 Jul 2008 17:38:22 -0400
6716785: implicit null checks not triggering with CompressedOops
Summary: allocate alignment-sized page(s) below java heap so that memory accesses at heap_base+1page give signal and cause an implicit null check
Reviewed-by: kvn, jmasa, phh, jcoomes
2 /*
3 * Copyright 2004 Sun Microsystems, Inc. All Rights Reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
21 * CA 95054 USA or visit www.sun.com if you need additional information or
22 * have any questions.
23 *
24 */
26 # include "incls/_precompiled.incl"
27 # include "incls/_psGenerationCounters.cpp.incl"
30 PSGenerationCounters::PSGenerationCounters(const char* name,
31 int ordinal, int spaces,
32 PSVirtualSpace* v):
33 _ps_virtual_space(v) {
35 if (UsePerfData) {
37 EXCEPTION_MARK;
38 ResourceMark rm;
40 const char* cns = PerfDataManager::name_space("generation", ordinal);
42 _name_space = NEW_C_HEAP_ARRAY(char, strlen(cns)+1);
43 strcpy(_name_space, cns);
45 const char* cname = PerfDataManager::counter_name(_name_space, "name");
46 PerfDataManager::create_string_constant(SUN_GC, cname, name, CHECK);
48 cname = PerfDataManager::counter_name(_name_space, "spaces");
49 PerfDataManager::create_constant(SUN_GC, cname, PerfData::U_None,
50 spaces, CHECK);
52 cname = PerfDataManager::counter_name(_name_space, "minCapacity");
53 PerfDataManager::create_constant(SUN_GC, cname, PerfData::U_Bytes,
54 _ps_virtual_space->committed_size(), CHECK);
56 cname = PerfDataManager::counter_name(_name_space, "maxCapacity");
57 PerfDataManager::create_constant(SUN_GC, cname, PerfData::U_Bytes,
58 _ps_virtual_space->reserved_size(), CHECK);
60 cname = PerfDataManager::counter_name(_name_space, "capacity");
61 _current_size = PerfDataManager::create_variable(SUN_GC, cname,
62 PerfData::U_Bytes, _ps_virtual_space->committed_size(), CHECK);
63 }
64 }