1 /*

     2  * Copyright (c) 2019, Red Hat, Inc. All rights reserved.

     3  *

     4  * This code is free software; you can redistribute it and/or modify it

     5  * under the terms of the GNU General Public License version 2 only, as

     6  * published by the Free Software Foundation.

     7  *

     8  * This code is distributed in the hope that it will be useful, but WITHOUT

     9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    11  * version 2 for more details (a copy is included in the LICENSE file that

    12  * accompanied this code).

    13  *

    14  * You should have received a copy of the GNU General Public License version

    15  * 2 along with this work; if not, write to the Free Software Foundation,

    16  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    17  *

    18  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    19  * or visit www.oracle.com if you need additional information or have any

    20  * questions.

    21  *

    22  */

    23 

    24 #include "precompiled.hpp"

    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 

    36 bool ShenandoahBarrierSetNMethod::nmethod_entry_barrier(nmethod* nm) {

    37   ShenandoahReentrantLock* lock = ShenandoahNMethod::lock_for_nmethod(nm);

    38   assert(lock != NULL, "Must be");

    39   ShenandoahReentrantLocker locker(lock);

    40 

    41   if (!is_armed(nm)) {

    42     // Some other thread got here first and healed the oops

    43     // and disarmed the nmethod.

    44     return true;

    45   }

    46 

    47   if (nm->is_unloading()) {

    48     // We don't need to take the lock when unlinking nmethods from

    49     // the Method, because it is only concurrently unlinked by

    50     // the entry barrier, which acquires the per nmethod lock.

    51     nm->unlink_from_method();

    52 

    53     // We can end up calling nmethods that are unloading

    54     // since we clear compiled ICs lazily. Returning false

    55     // will re-resovle the call and update the compiled IC.

    56     return false;

    57   }

    58 

    59   // Heal oops and disarm

    60   ShenandoahEvacOOMScope scope;

    61   ShenandoahNMethod::heal_nmethod(nm);

    62   ShenandoahNMethod::disarm_nmethod(nm);

    63   return true;

    64 }

    65 

    66 int ShenandoahBarrierSetNMethod::disarmed_value() const {

    67   return ShenandoahCodeRoots::disarmed_value();

    68 }

    69 

    70 ByteSize ShenandoahBarrierSetNMethod::thread_disarmed_offset() const {

    71   return ShenandoahThreadLocalData::disarmed_value_offset();

    72 }

    73 

    74 int* ShenandoahBarrierSetNMethod::disarmed_value_address() const {

    75   return ShenandoahCodeRoots::disarmed_value_address();

    76 }