1 /*
 2  * Copyright (c) 2019, 2022, Red Hat, Inc. 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 
25 
26 #include "gc/shenandoah/shenandoahBarrierSetNMethod.hpp"
27 #include "gc/shenandoah/shenandoahClosures.inline.hpp"
28 #include "gc/shenandoah/shenandoahCodeRoots.hpp"
29 #include "gc/shenandoah/shenandoahHeap.inline.hpp"
30 #include "gc/shenandoah/shenandoahLock.hpp"
31 #include "gc/shenandoah/shenandoahNMethod.inline.hpp"
32 #include "gc/shenandoah/shenandoahThreadLocalData.hpp"
33 #include "memory/iterator.hpp"
34 #include "memory/resourceArea.hpp"
35 #include "runtime/threadWXSetters.inline.hpp"
36 
37 bool ShenandoahBarrierSetNMethod::nmethod_entry_barrier(nmethod* nm) {
38   if (!is_armed(nm)) {
39     // Some other thread got here first and healed the oops
40     // and disarmed the nmethod. No need to continue.
41     return true;
42   }
43 
44   ShenandoahReentrantLock* lock = ShenandoahNMethod::lock_for_nmethod(nm);
45   assert(lock != nullptr, "Must be");
46   ShenandoahReentrantLocker locker(lock);
47 
48   if (!is_armed(nm)) {
49     // Some other thread managed to complete while we were
50     // waiting for lock. No need to continue.
51     return true;
52   }
53 
54   MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, Thread::current());)
55 
56   if (nm->is_unloading()) {
57     // We don't need to take the lock when unlinking nmethods from
58     // the Method, because it is only concurrently unlinked by
59     // the entry barrier, which acquires the per nmethod lock.
60     nm->unlink_from_method();
61 
62     // We can end up calling nmethods that are unloading
63     // since we clear compiled ICs lazily. Returning false
64     // will re-resovle the call and update the compiled IC.
65     return false;
66   }
67 
68   // Heal oops
69   ShenandoahNMethod::heal_nmethod(nm);
70 
71   // CodeCache unloading support
72   nm->mark_as_maybe_on_stack();
73 
74   // Disarm
75   ShenandoahNMethod::disarm_nmethod(nm);
76   return true;
77 }
--- EOF ---