1 /*
   2  * Copyright (c) 2020, 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 #ifndef SHARE_GC_SHENANDOAH_SHENANDOAHEVACOOMHANDLER_INLINE_HPP
  26 #define SHARE_GC_SHENANDOAH_SHENANDOAHEVACOOMHANDLER_INLINE_HPP
  27 
  28 #include "gc/shenandoah/shenandoahEvacOOMHandler.hpp"
  29 #include "gc/shenandoah/shenandoahHeap.inline.hpp"
  30 #include "gc/shenandoah/shenandoahThreadLocalData.hpp"
  31 #include "runtime/atomic.hpp"
  32 
  33 void ShenandoahEvacOOMHandler::enter_evacuation(Thread* thr) {
  34   jint threads_in_evac = Atomic::load_acquire(&_threads_in_evac);
  35 
  36   uint8_t level = ShenandoahThreadLocalData::push_evac_oom_scope(thr);
  37   if ((threads_in_evac & OOM_MARKER_MASK) != 0) {
  38     wait_for_no_evac_threads();
  39     return;
  40   }
  41 
  42   // Nesting case, this thread already registered
  43   if (level != 0) {
  44      return;
  45   }
  46   // Entering top level scope, register this thread.
  47   register_thread(thr);
  48 }
  49 
  50 void ShenandoahEvacOOMHandler::leave_evacuation(Thread* thr) {
  51   uint8_t level = ShenandoahThreadLocalData::pop_evac_oom_scope(thr);
  52   // Not top level, just return
  53   if (level > 1) {
  54     return;
  55   }
  56 
  57   // Leaving top level scope, unregister this thread.
  58   unregister_thread(thr);
  59 }
  60 
  61 ShenandoahEvacOOMScope::ShenandoahEvacOOMScope() :
  62   _thread(Thread::current()) {
  63   ShenandoahHeap::heap()->enter_evacuation(_thread);
  64 }
  65 
  66 ShenandoahEvacOOMScope::ShenandoahEvacOOMScope(Thread* t) :
  67   _thread(t) {
  68   ShenandoahHeap::heap()->enter_evacuation(_thread);
  69 }
  70 
  71 ShenandoahEvacOOMScope::~ShenandoahEvacOOMScope() {
  72   ShenandoahHeap::heap()->leave_evacuation(_thread);
  73 }
  74 
  75 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHEVACOOMHANDLER_INLINE_HPP