1 /*
   2  * Copyright (c) 2017, 2018, 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 #ifndef SHARE_VM_GC_SHENANDOAH_SHENANDOAH_WORKGROUP_HPP
  25 #define SHARE_VM_GC_SHENANDOAH_SHENANDOAH_WORKGROUP_HPP
  26 
  27 #include "gc_implementation/shenandoah/shenandoahTaskqueue.hpp"
  28 #include "utilities/workgroup.hpp"
  29 #include "memory/allocation.hpp"
  30 
  31 class ShenandoahWorkGang;
  32 
  33 class ShenandoahWorkerScope : public StackObj {
  34 private:
  35   uint      _n_workers;
  36   ShenandoahWorkGang* _workers;
  37 public:
  38   ShenandoahWorkerScope(ShenandoahWorkGang* workers, uint nworkers, const char* msg, bool do_check = true);
  39   ~ShenandoahWorkerScope();
  40 };
  41 
  42 class ShenandoahPushWorkerScope : StackObj {
  43 private:
  44   uint      _n_workers;
  45   uint      _old_workers;
  46   ShenandoahWorkGang* _workers;
  47 
  48 public:
  49   ShenandoahPushWorkerScope(ShenandoahWorkGang* workers, uint nworkers, bool do_check = true);
  50   ~ShenandoahPushWorkerScope();
  51 };
  52 
  53 class ShenandoahWorkGang : public FlexibleWorkGang {
  54 public:
  55   ShenandoahWorkGang(const char* name, uint workers,
  56                    bool are_GC_task_threads,
  57                    bool are_ConcurrentGC_threads) :
  58     FlexibleWorkGang(name, workers, are_GC_task_threads, are_ConcurrentGC_threads) {
  59   }
  60 
  61   // Hide FlexibleWorkGang's implementation, avoid _active_workers == _total_workers
  62   // check
  63   void set_active_workers(uint v) {
  64     assert(v <= _total_workers,
  65            "Trying to set more workers active than there are");
  66     _active_workers = MIN2(v, _total_workers);
  67     assert(v != 0, "Trying to set active workers to 0");
  68     _active_workers = MAX2(1U, _active_workers);
  69   }
  70 };
  71 
  72 #endif // SHARE_VM_GC_SHENANDOAH_SHENANDOAHWORKGROUP_HPP