brutisso@7195: /*
brutisso@7195:  * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
brutisso@7195:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
brutisso@7195:  *
brutisso@7195:  * This code is free software; you can redistribute it and/or modify it
brutisso@7195:  * under the terms of the GNU General Public License version 2 only, as
brutisso@7195:  * published by the Free Software Foundation.
brutisso@7195:  *
brutisso@7195:  * This code is distributed in the hope that it will be useful, but WITHOUT
brutisso@7195:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
brutisso@7195:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
brutisso@7195:  * version 2 for more details (a copy is included in the LICENSE file that
brutisso@7195:  * accompanied this code).
brutisso@7195:  *
brutisso@7195:  * You should have received a copy of the GNU General Public License version
brutisso@7195:  * 2 along with this work; if not, write to the Free Software Foundation,
brutisso@7195:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
brutisso@7195:  *
brutisso@7195:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
brutisso@7195:  * or visit www.oracle.com if you need additional information or have any
brutisso@7195:  * questions.
brutisso@7195:  *
brutisso@7195:  */
brutisso@7195: 
brutisso@7195: #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGIONTYPE_HPP
brutisso@7195: #define SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGIONTYPE_HPP
brutisso@7195: 
brutisso@7195: #include "memory/allocation.hpp"
brutisso@7195: 
brutisso@7195: #define hrt_assert_is_valid(tag) \
brutisso@7195:   assert(is_valid((tag)), err_msg("invalid HR type: %u", (uint) (tag)))
brutisso@7195: 
brutisso@7195: class HeapRegionType VALUE_OBJ_CLASS_SPEC {
brutisso@7195: private:
brutisso@7195:   // We encode the value of the heap region type so the generation can be
brutisso@7195:   // determined quickly. The tag is split into two parts:
brutisso@7195:   //
brutisso@7195:   //   major type (young, humongous)                         : top N-1 bits
brutisso@7195:   //   minor type (eden / survivor, starts / cont hum, etc.) : bottom 1 bit
brutisso@7195:   //
brutisso@7195:   // If there's need to increase the number of minor types in the
brutisso@7195:   // future, we'll have to increase the size of the latter and hence
brutisso@7195:   // decrease the size of the former.
brutisso@7195:   //
brutisso@7195:   // 0000 0 [ 0] Free
brutisso@7195:   //
brutisso@7195:   // 0001 0      Young Mask
brutisso@7195:   // 0001 0 [ 2] Eden
brutisso@7195:   // 0001 1 [ 3] Survivor
brutisso@7195:   //
brutisso@7195:   // 0010 0      Humongous Mask
brutisso@7195:   // 0010 0 [ 4] Humongous Starts
brutisso@7195:   // 0010 1 [ 5] Humongous Continues
brutisso@7195:   //
brutisso@7195:   // 01000 [ 8] Old
brutisso@7195:   typedef enum {
brutisso@7195:     FreeTag       = 0,
brutisso@7195: 
brutisso@7195:     YoungMask     = 2,
brutisso@7195:     EdenTag       = YoungMask,
brutisso@7195:     SurvTag       = YoungMask + 1,
brutisso@7195: 
brutisso@7195:     HumMask       = 4,
brutisso@7195:     HumStartsTag  = HumMask,
brutisso@7195:     HumContTag    = HumMask + 1,
brutisso@7195: 
brutisso@7195:     OldTag        = 8
brutisso@7195:   } Tag;
brutisso@7195: 
brutisso@7195:   volatile Tag _tag;
brutisso@7195: 
brutisso@7195:   static bool is_valid(Tag tag);
brutisso@7195: 
brutisso@7195:   Tag get() const {
brutisso@7195:     hrt_assert_is_valid(_tag);
brutisso@7195:     return _tag;
brutisso@7195:   }
brutisso@7195: 
brutisso@7195:   // Sets the type to 'tag'.
brutisso@7195:   void set(Tag tag) {
brutisso@7195:     hrt_assert_is_valid(tag);
brutisso@7195:     hrt_assert_is_valid(_tag);
brutisso@7195:     _tag = tag;
brutisso@7195:   }
brutisso@7195: 
brutisso@7195:   // Sets the type to 'tag', expecting the type to be 'before'. This
brutisso@7195:   // is available for when we want to add sanity checking to the type
brutisso@7195:   // transition.
brutisso@7195:   void set_from(Tag tag, Tag before) {
brutisso@7195:     hrt_assert_is_valid(tag);
brutisso@7195:     hrt_assert_is_valid(before);
brutisso@7195:     hrt_assert_is_valid(_tag);
brutisso@7195:     assert(_tag == before,
brutisso@7195:            err_msg("HR tag: %u, expected: %u new tag; %u", _tag, before, tag));
brutisso@7195:     _tag = tag;
brutisso@7195:   }
brutisso@7195: 
brutisso@7195: public:
brutisso@7195:   // Queries
brutisso@7195: 
brutisso@7195:   bool is_free() const { return get() == FreeTag; }
brutisso@7195: 
brutisso@7195:   bool is_young()    const { return (get() & YoungMask) != 0; }
brutisso@7195:   bool is_eden()     const { return get() == EdenTag;  }
brutisso@7195:   bool is_survivor() const { return get() == SurvTag;  }
brutisso@7195: 
brutisso@7195:   bool is_humongous()           const { return (get() & HumMask) != 0; }
brutisso@7195:   bool is_starts_humongous()    const { return get() == HumStartsTag;  }
brutisso@7195:   bool is_continues_humongous() const { return get() == HumContTag;    }
brutisso@7195: 
brutisso@7195:   bool is_old() const { return get() == OldTag; }
brutisso@7195: 
brutisso@7195:   // Setters
brutisso@7195: 
brutisso@7195:   void set_free() { set(FreeTag); }
brutisso@7195: 
brutisso@7195:   void set_eden()        { set_from(EdenTag, FreeTag); }
brutisso@7195:   void set_eden_pre_gc() { set_from(EdenTag, SurvTag); }
brutisso@7195:   void set_survivor()    { set_from(SurvTag, FreeTag); }
brutisso@7195: 
brutisso@7195:   void set_starts_humongous()    { set_from(HumStartsTag, FreeTag); }
brutisso@7195:   void set_continues_humongous() { set_from(HumContTag,   FreeTag); }
brutisso@7195: 
brutisso@7195:   void set_old() { set(OldTag); }
brutisso@7195: 
brutisso@7195:   // Misc
brutisso@7195: 
brutisso@7195:   const char* get_str() const;
brutisso@7195:   const char* get_short_str() const;
brutisso@7195: 
brutisso@7195:   HeapRegionType() : _tag(FreeTag) { hrt_assert_is_valid(_tag); }
brutisso@7195: };
brutisso@7195: 
brutisso@7195: #endif // SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGIONTYPE_HPP