1 /*
   2  * Copyright (c) 2001, 2013, Oracle and/or its affiliates. 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_VM_GC_IMPLEMENTATION_SHARED_CONCURRENTGCTHREAD_HPP
  26 #define SHARE_VM_GC_IMPLEMENTATION_SHARED_CONCURRENTGCTHREAD_HPP
  27 
  28 #include "utilities/macros.hpp"
  29 #include "gc_implementation/shared/suspendibleThreadSet.hpp"
  30 #include "runtime/thread.hpp"
  31 
  32 class ConcurrentGCThread: public NamedThread {
  33   friend class VMStructs;
  34 
  35 protected:
  36   bool _should_terminate;
  37   bool _has_terminated;
  38 
  39   enum CGC_flag_type {
  40     CGC_nil           = 0x0,
  41     CGC_dont_suspend  = 0x1,
  42     CGC_CGC_safepoint = 0x2,
  43     CGC_VM_safepoint  = 0x4
  44   };
  45 
  46   static int _CGC_flag;
  47 
  48   static bool CGC_flag_is_set(int b)       { return (_CGC_flag & b) != 0; }
  49   static int set_CGC_flag(int b)           { return _CGC_flag |= b; }
  50   static int reset_CGC_flag(int b)         { return _CGC_flag &= ~b; }
  51 
  52   // Create and start the thread (setting it's priority high.)
  53   void create_and_start();
  54 
  55   // Do initialization steps in the thread: record stack base and size,
  56   // init thread local storage, set JNI handle block.
  57   void initialize_in_thread();
  58 
  59   // Wait until Universe::is_fully_initialized();
  60   void wait_for_universe_init();
  61 
  62   // Record that the current thread is terminating, and will do more
  63   // concurrent work.
  64   void terminate();
  65 
  66 public:
  67   // Constructor
  68 
  69   ConcurrentGCThread();
  70   ~ConcurrentGCThread() {} // Exists to call NamedThread destructor.
  71 
  72   // Tester
  73   bool is_ConcurrentGC_thread() const          { return true;       }
  74 };
  75 
  76 // The SurrogateLockerThread is used by concurrent GC threads for
  77 // manipulating Java monitors, in particular, currently for
  78 // manipulating the pending_list_lock. XXX
  79 class SurrogateLockerThread: public JavaThread {
  80   friend class VMStructs;
  81  public:
  82   enum SLT_msg_type {
  83     empty = 0,           // no message
  84     acquirePLL,          // acquire pending list lock
  85     releaseAndNotifyPLL  // notify and release pending list lock
  86   };
  87  private:
  88   // the following are shared with the CMSThread
  89   SLT_msg_type  _buffer;  // communication buffer
  90   Monitor       _monitor; // monitor controlling buffer
  91   BasicLock     _basicLock; // used for PLL locking
  92 
  93  public:
  94   static SurrogateLockerThread* make(TRAPS);
  95 
  96   // Terminate VM with error message that SLT needed but not yet created.
  97   static void report_missing_slt();
  98 
  99   SurrogateLockerThread();
 100 
 101   bool is_hidden_from_external_view() const     { return true; }
 102 
 103   void loop(); // main method
 104 
 105   void manipulatePLL(SLT_msg_type msg);
 106 
 107 };
 108 
 109 #endif // SHARE_VM_GC_IMPLEMENTATION_SHARED_CONCURRENTGCTHREAD_HPP