| /* |
| * Copyright (c) 1997, 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_MEMORY_HEAP_HPP |
| #define SHARE_VM_MEMORY_HEAP_HPP |
| |
| #include "code/codeBlob.hpp" |
| #include "memory/allocation.hpp" |
| #include "memory/virtualspace.hpp" |
| #include "utilities/macros.hpp" |
| |
| // Blocks |
| |
| class HeapBlock { |
| friend class VMStructs; |
| |
| public: |
| struct Header { |
| size_t _length; // the length in segments |
| bool _used; // Used bit |
| }; |
| |
| protected: |
| union { |
| Header _header; |
| int64_t _padding[ (sizeof(Header) + sizeof(int64_t)-1) / sizeof(int64_t) ]; |
| // pad to 0 mod 8 |
| }; |
| |
| public: |
| // Initialization |
| void initialize(size_t length) { _header._length = length; set_used(); } |
| |
| // Accessors |
| void* allocated_space() const { return (void*)(this + 1); } |
| size_t length() const { return _header._length; } |
| |
| // Used/free |
| void set_used() { _header._used = true; } |
| void set_free() { _header._used = false; } |
| bool free() { return !_header._used; } |
| }; |
| |
| class FreeBlock: public HeapBlock { |
| friend class VMStructs; |
| protected: |
| FreeBlock* _link; |
| |
| public: |
| // Initialization |
| void initialize(size_t length) { HeapBlock::initialize(length); _link= NULL; } |
| |
| // Merging |
| void set_length(size_t l) { _header._length = l; } |
| |
| // Accessors |
| FreeBlock* link() const { return _link; } |
| void set_link(FreeBlock* link) { _link = link; } |
| }; |
| |
| class CodeHeap : public CHeapObj<mtCode> { |
| friend class VMStructs; |
| protected: |
| VirtualSpace _memory; // the memory holding the blocks |
| VirtualSpace _segmap; // the memory holding the segment map |
| |
| size_t _number_of_committed_segments; |
| size_t _number_of_reserved_segments; |
| size_t _segment_size; |
| int _log2_segment_size; |
| |
| size_t _next_segment; |
| |
| FreeBlock* _freelist; |
| size_t _freelist_segments; // No. of segments in freelist |
| int _freelist_length; |
| size_t _max_allocated_capacity; // Peak capacity that was allocated during lifetime of the heap |
| |
| const char* _name; // Name of the CodeHeap |
| const int _code_blob_type; // CodeBlobType it contains |
| int _blob_count; // Number of CodeBlobs |
| int _nmethod_count; // Number of nmethods |
| int _adapter_count; // Number of adapters |
| int _full_count; // Number of times the code heap was full |
| |
| |
| enum { free_sentinel = 0xFF }; |
| |
| // Helper functions |
| size_t size_to_segments(size_t size) const { return (size + _segment_size - 1) >> _log2_segment_size; } |
| size_t segments_to_size(size_t number_of_segments) const { return number_of_segments << _log2_segment_size; } |
| |
| size_t segment_for(void* p) const { return ((char*)p - _memory.low()) >> _log2_segment_size; } |
| bool is_segment_unused(int val) const { return val == free_sentinel; } |
| HeapBlock* block_at(size_t i) const { return (HeapBlock*)(_memory.low() + (i << _log2_segment_size)); } |
| |
| void mark_segmap_as_free(size_t beg, size_t end); |
| void mark_segmap_as_used(size_t beg, size_t end); |
| |
| // Freelist management helpers |
| FreeBlock* following_block(FreeBlock* b); |
| void insert_after(FreeBlock* a, FreeBlock* b); |
| bool merge_right (FreeBlock* a); |
| |
| // Toplevel freelist management |
| void add_to_freelist(HeapBlock* b); |
| FreeBlock* search_freelist(size_t length); |
| |
| // Iteration helpers |
| void* next_used(HeapBlock* b) const; |
| HeapBlock* block_start(void* p) const; |
| |
| // to perform additional actions on creation of executable code |
| void on_code_mapping(char* base, size_t size); |
| void clear(); // clears all heap contents |
| |
| public: |
| CodeHeap(const char* name, const int code_blob_type); |
| |
| // Heap extents |
| bool reserve(ReservedSpace rs, size_t committed_size, size_t segment_size); |
| bool expand_by(size_t size); // expands committed memory by size |
| |
| // Memory allocation |
| void* allocate (size_t size); // Allocate 'size' bytes in the code cache or return NULL |
| void deallocate(void* p); // Deallocate memory |
| // Free the tail of segments allocated by the last call to 'allocate()' which exceed 'used_size'. |
| // ATTENTION: this is only safe to use if there was no other call to 'allocate()' after |
| // 'p' was allocated. Only intended for freeing memory which would be otherwise |
| // wasted after the interpreter generation because we don't know the interpreter size |
| // beforehand and we also can't easily relocate the interpreter to a new location. |
| void deallocate_tail(void* p, size_t used_size); |
| |
| // Attributes |
| char* low_boundary() const { return _memory.low_boundary(); } |
| char* high() const { return _memory.high(); } |
| char* high_boundary() const { return _memory.high_boundary(); } |
| |
| bool contains(const void* p) const { return low_boundary() <= p && p < high(); } |
| bool contains_blob(const CodeBlob* blob) const { |
| // AOT CodeBlobs (i.e. AOTCompiledMethod) objects aren't allocated in the AOTCodeHeap but on the C-Heap. |
| // Only the code they are pointing to is located in the AOTCodeHeap. All other CodeBlobs are allocated |
| // directly in their corresponding CodeHeap with their code appended to the actual C++ object. |
| // So all CodeBlobs except AOTCompiledMethod are continuous in memory with their data and code while |
| // AOTCompiledMethod and their code/data is distributed in the C-Heap. This means we can use the |
| // address of a CodeBlob object in order to locate it in its heap while we have to use the address |
| // of the actual code an AOTCompiledMethod object is pointing to in order to locate it. |
| // Notice that for an ordinary CodeBlob with code size zero, code_begin() may point beyond the object! |
| const void* start = AOT_ONLY( (code_blob_type() == CodeBlobType::AOT) ? blob->code_begin() : ) (void*)blob; |
| return contains(start); |
| } |
| |
| virtual void* find_start(void* p) const; // returns the block containing p or NULL |
| virtual CodeBlob* find_blob_unsafe(void* start) const; |
| size_t alignment_unit() const; // alignment of any block |
| size_t alignment_offset() const; // offset of first byte of any block, within the enclosing alignment unit |
| static size_t header_size(); // returns the header size for each heap block |
| |
| size_t segment_size() const { return _segment_size; } // for CodeHeapState |
| HeapBlock* first_block() const; // for CodeHeapState |
| HeapBlock* next_block(HeapBlock* b) const; // for CodeHeapState |
| |
| FreeBlock* freelist() const { return _freelist; } // for CodeHeapState |
| |
| size_t allocated_in_freelist() const { return _freelist_segments * CodeCacheSegmentSize; } |
| int freelist_length() const { return _freelist_length; } // number of elements in the freelist |
| |
| // returns the first block or NULL |
| virtual void* first() const { return next_used(first_block()); } |
| // returns the next block given a block p or NULL |
| virtual void* next(void* p) const { return next_used(next_block(block_start(p))); } |
| |
| // Statistics |
| size_t capacity() const; |
| size_t max_capacity() const; |
| int allocated_segments() const; |
| size_t allocated_capacity() const; |
| size_t max_allocated_capacity() const { return _max_allocated_capacity; } |
| size_t unallocated_capacity() const { return max_capacity() - allocated_capacity(); } |
| |
| // Returns true if the CodeHeap contains CodeBlobs of the given type |
| bool accepts(int code_blob_type) const { return (_code_blob_type == CodeBlobType::All) || |
| (_code_blob_type == code_blob_type); } |
| int code_blob_type() const { return _code_blob_type; } |
| |
| // Debugging / Profiling |
| const char* name() const { return _name; } |
| int blob_count() { return _blob_count; } |
| int nmethod_count() { return _nmethod_count; } |
| void set_nmethod_count(int count) { _nmethod_count = count; } |
| int adapter_count() { return _adapter_count; } |
| void set_adapter_count(int count) { _adapter_count = count; } |
| int full_count() { return _full_count; } |
| void report_full() { _full_count++; } |
| |
| private: |
| size_t heap_unallocated_capacity() const; |
| |
| public: |
| // Debugging |
| void verify() PRODUCT_RETURN; |
| void print() PRODUCT_RETURN; |
| }; |
| |
| #endif // SHARE_VM_MEMORY_HEAP_HPP |