1/*
2 * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23
24#include "precompiled.hpp"
25#include "code/nmethod.hpp"
26#include "gc/z/zBarrierSetNMethod.hpp"
27#include "gc/z/zGlobals.hpp"
28#include "gc/z/zLock.inline.hpp"
29#include "gc/z/zOopClosures.hpp"
30#include "gc/z/zNMethod.hpp"
31#include "gc/z/zThreadLocalData.hpp"
32#include "logging/log.hpp"
33
34bool ZBarrierSetNMethod::nmethod_entry_barrier(nmethod* nm) {
35 ZLocker<ZReentrantLock> locker(ZNMethod::lock_for_nmethod(nm));
36 log_trace(nmethod, barrier)("Entered critical zone for %p", nm);
37
38 if (!is_armed(nm)) {
39 // Some other thread got here first and healed the oops
40 // and disarmed the nmethod.
41 return true;
42 }
43
44 if (nm->is_unloading()) {
45 // We don't need to take the lock when unlinking nmethods from
46 // the Method, because it is only concurrently unlinked by
47 // the entry barrier, which acquires the per nmethod lock.
48 nm->unlink_from_method(false /* acquire_lock */);
49
50 // We can end up calling nmethods that are unloading
51 // since we clear compiled ICs lazily. Returning false
52 // will re-resovle the call and update the compiled IC.
53 return false;
54 }
55
56 // Heal oops and disarm
57 ZNMethodOopClosure cl;
58 ZNMethod::nmethod_oops_do(nm, &cl);
59 disarm(nm);
60
61 return true;
62}
63
64int ZBarrierSetNMethod::disarmed_value() const {
65 // We override the default BarrierSetNMethod::disarmed_value() since
66 // this can be called by GC threads, which doesn't keep an up to date
67 // address_bad_mask.
68 const uintptr_t disarmed_addr = ((uintptr_t)&ZAddressBadMask) + ZNMethodDisarmedOffset;
69 return *((int*)disarmed_addr);
70}
71
72ByteSize ZBarrierSetNMethod::thread_disarmed_offset() const {
73 return ZThreadLocalData::nmethod_disarmed_offset();
74}
75