| /* |
| * Copyright (c) 1998, 2018, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| #ifndef SHARE_VM_ADLC_ARENA_HPP |
| #define SHARE_VM_ADLC_ARENA_HPP |
| |
| // All classes in the virtual machine must be subclassed |
| // by one of the following allocation classes: |
| // |
| // |
| // For objects allocated in the C-heap (managed by: free & malloc). |
| // - CHeapObj |
| // |
| // |
| // For embedded objects. |
| // - ValueObj |
| // |
| // For classes used as name spaces. |
| // - AllStatic |
| // |
| |
| class CHeapObj { |
| public: |
| void* operator new(size_t size) throw(); |
| void operator delete(void* p); |
| void* new_array(size_t size); |
| }; |
| |
| |
| // Base class for objects used as value objects. |
| // Calling new or delete will result in fatal error. |
| |
| class ValueObj { |
| public: |
| void* operator new(size_t size) throw(); |
| void operator delete(void* p); |
| }; |
| |
| // Base class for classes that constitute name spaces. |
| |
| class AllStatic { |
| public: |
| void* operator new(size_t size) throw(); |
| void operator delete(void* p); |
| }; |
| |
| |
| //------------------------------Chunk------------------------------------------ |
| // Linked list of raw memory chunks |
| class Chunk: public CHeapObj { |
| private: |
| // This ordinary operator delete is needed even though not used, so the |
| // below two-argument operator delete will be treated as a placement |
| // delete rather than an ordinary sized delete; see C++14 3.7.4.2/p2. |
| void operator delete(void* p); |
| public: |
| void* operator new(size_t size, size_t length) throw(); |
| void operator delete(void* p, size_t length); |
| Chunk(size_t length); |
| |
| enum { |
| init_size = 1*1024, // Size of first chunk |
| size = 32*1024 // Default size of an Arena chunk (following the first) |
| }; |
| Chunk* _next; // Next Chunk in list |
| size_t _len; // Size of this Chunk |
| |
| void chop(); // Chop this chunk |
| void next_chop(); // Chop next chunk |
| |
| // Boundaries of data area (possibly unused) |
| char* bottom() const { return ((char*) this) + sizeof(Chunk); } |
| char* top() const { return bottom() + _len; } |
| }; |
| |
| |
| //------------------------------Arena------------------------------------------ |
| // Fast allocation of memory |
| class Arena: public CHeapObj { |
| protected: |
| friend class ResourceMark; |
| friend class HandleMark; |
| friend class NoHandleMark; |
| Chunk *_first; // First chunk |
| Chunk *_chunk; // current chunk |
| char *_hwm, *_max; // High water mark and max in current chunk |
| void* grow(size_t x); // Get a new Chunk of at least size x |
| size_t _size_in_bytes; // Size of arena (used for memory usage tracing) |
| public: |
| Arena(); |
| Arena(size_t init_size); |
| Arena(Arena *old); |
| ~Arena() { _first->chop(); } |
| char* hwm() const { return _hwm; } |
| |
| // Fast allocate in the arena. Common case is: pointer test + increment. |
| void* Amalloc(size_t x) { |
| #ifdef _LP64 |
| x = (x + (8-1)) & ((unsigned)(-8)); |
| #else |
| x = (x + (4-1)) & ((unsigned)(-4)); |
| #endif |
| if (_hwm + x > _max) { |
| return grow(x); |
| } else { |
| char *old = _hwm; |
| _hwm += x; |
| return old; |
| } |
| } |
| // Further assume size is padded out to words |
| // Warning: in LP64, Amalloc_4 is really Amalloc_8 |
| void *Amalloc_4(size_t x) { |
| assert( (x&(sizeof(char*)-1)) == 0, "misaligned size" ); |
| if (_hwm + x > _max) { |
| return grow(x); |
| } else { |
| char *old = _hwm; |
| _hwm += x; |
| return old; |
| } |
| } |
| |
| // Fast delete in area. Common case is: NOP (except for storage reclaimed) |
| void Afree(void *ptr, size_t size) { |
| if (((char*)ptr) + size == _hwm) _hwm = (char*)ptr; |
| } |
| |
| void *Acalloc( size_t items, size_t x ); |
| void *Arealloc( void *old_ptr, size_t old_size, size_t new_size ); |
| |
| // Reset this Arena to empty, and return this Arenas guts in a new Arena. |
| Arena *reset(void); |
| |
| // Determine if pointer belongs to this Arena or not. |
| bool contains( const void *ptr ) const; |
| |
| // Total of all chunks in use (not thread-safe) |
| size_t used() const; |
| |
| // Total # of bytes used |
| size_t size_in_bytes() const { return _size_in_bytes; } |
| void set_size_in_bytes(size_t size) { _size_in_bytes = size; } |
| }; |
| |
| #endif // SHARE_VM_ADLC_ARENA_HPP |