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/shenandoahThreadLocalData.hpp"
  30 #include "runtime/atomic.hpp"
  31 
  32 void ShenandoahEvacOOMHandler::enter_evacuation(Thread* thr) {
  33   jint threads_in_evac = Atomic::load_acquire(&_threads_in_evac);
  34 
  35   uint8_t level = ShenandoahThreadLocalData::push_evac_oom_scope(thr);
  36   if ((threads_in_evac & OOM_MARKER_MASK) != 0) {
  37     wait_for_no_evac_threads();
  38     return;
  39   }
  40 
  41   // Nesting case, this thread already registered
  42   if (level != 0) {
  43      return;
  44   }
  45   // Entering top level scope, register this thread.
  46   register_thread_to_protocol(thr);
  47 }
  48 
  49 void ShenandoahEvacOOMHandler::leave_evacuation(Thread* thr) {
  50   uint8_t level = ShenandoahThreadLocalData::pop_evac_oom_scope(thr);
  51   // Not top level, just return
  52   if (level > 1) {
  53     return;
  54   }
  55 
  56   // Leaving top level scope, unregister this thread.
  57   unregister_thread_to_protocol(thr);
  58 }
  59 
  60 ShenandoahEvacOOMScope::ShenandoahEvacOOMScope() :
  61   _heap(ShenandoahHeap::heap()),
  62   _thread(Thread::current()) {
  63   _heap->enter_evacuation(_thread);
  64 }
  65 
  66 ShenandoahEvacOOMScope::ShenandoahEvacOOMScope(Thread* t) :
  67   _heap(ShenandoahHeap::heap()),
  68   _thread(t) {
  69   _heap->enter_evacuation(_thread);
  70 }
  71 
  72 ShenandoahEvacOOMScope::ShenandoahEvacOOMScope(ShenandoahHeap* heap) :
  73   _heap(heap),
  74   _thread(Thread::current()) {
  75   _heap->enter_evacuation(_thread);
  76 }
  77 
  78 ShenandoahEvacOOMScope::ShenandoahEvacOOMScope(ShenandoahHeap* heap, Thread* t) :
  79   _heap(heap),
  80   _thread(t) {
  81   _heap->enter_evacuation(_thread);
  82 }
  83 
  84 ShenandoahEvacOOMScope::~ShenandoahEvacOOMScope() {
  85   _heap->leave_evacuation(_thread);
  86 }
  87 
  88 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHEVACOOMHANDLER_INLINE_HPP