Mercurial > hg > truffle
view src/share/vm/memory/heap.cpp @ 7535:f057113c7a87
provide TargetDescription in LoweringTool
author | Lukas Stadler <lukas.stadler@jku.at> |
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date | Wed, 23 Jan 2013 16:46:20 +0100 |
parents | e522a00b91aa |
children | 3c29f7da5c66 |
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/* * Copyright (c) 1997, 2012, 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. * */ #include "precompiled.hpp" #include "memory/heap.hpp" #include "oops/oop.inline.hpp" #include "runtime/os.hpp" #include "services/memTracker.hpp" size_t CodeHeap::header_size() { return sizeof(HeapBlock); } // Implementation of Heap CodeHeap::CodeHeap() { _number_of_committed_segments = 0; _number_of_reserved_segments = 0; _segment_size = 0; _log2_segment_size = 0; _next_segment = 0; _freelist = NULL; _free_segments = 0; } void CodeHeap::mark_segmap_as_free(size_t beg, size_t end) { assert(0 <= beg && beg < _number_of_committed_segments, "interval begin out of bounds"); assert(beg < end && end <= _number_of_committed_segments, "interval end out of bounds"); // setup _segmap pointers for faster indexing address p = (address)_segmap.low() + beg; address q = (address)_segmap.low() + end; // initialize interval while (p < q) *p++ = 0xFF; } void CodeHeap::mark_segmap_as_used(size_t beg, size_t end) { assert(0 <= beg && beg < _number_of_committed_segments, "interval begin out of bounds"); assert(beg < end && end <= _number_of_committed_segments, "interval end out of bounds"); // setup _segmap pointers for faster indexing address p = (address)_segmap.low() + beg; address q = (address)_segmap.low() + end; // initialize interval int i = 0; while (p < q) { *p++ = i++; if (i == 0xFF) i = 1; } } static size_t align_to_page_size(size_t size) { const size_t alignment = (size_t)os::vm_page_size(); assert(is_power_of_2(alignment), "no kidding ???"); return (size + alignment - 1) & ~(alignment - 1); } static size_t align_to_allocation_size(size_t size) { const size_t alignment = (size_t)os::vm_allocation_granularity(); assert(is_power_of_2(alignment), "no kidding ???"); return (size + alignment - 1) & ~(alignment - 1); } void CodeHeap::on_code_mapping(char* base, size_t size) { #ifdef LINUX extern void linux_wrap_code(char* base, size_t size); linux_wrap_code(base, size); #endif } bool CodeHeap::reserve(size_t reserved_size, size_t committed_size, size_t segment_size) { assert(reserved_size >= committed_size, "reserved < committed"); assert(segment_size >= sizeof(FreeBlock), "segment size is too small"); assert(is_power_of_2(segment_size), "segment_size must be a power of 2"); _segment_size = segment_size; _log2_segment_size = exact_log2(segment_size); // Reserve and initialize space for _memory. const size_t page_size = os::can_execute_large_page_memory() ? os::page_size_for_region(committed_size, reserved_size, 8) : os::vm_page_size(); const size_t granularity = os::vm_allocation_granularity(); const size_t r_align = MAX2(page_size, granularity); const size_t r_size = align_size_up(reserved_size, r_align); const size_t c_size = align_size_up(committed_size, page_size); const size_t rs_align = page_size == (size_t) os::vm_page_size() ? 0 : MAX2(page_size, granularity); ReservedCodeSpace rs(r_size, rs_align, rs_align > 0); os::trace_page_sizes("code heap", committed_size, reserved_size, page_size, rs.base(), rs.size()); if (!_memory.initialize(rs, c_size)) { return false; } on_code_mapping(_memory.low(), _memory.committed_size()); _number_of_committed_segments = number_of_segments(_memory.committed_size()); _number_of_reserved_segments = number_of_segments(_memory.reserved_size()); assert(_number_of_reserved_segments >= _number_of_committed_segments, "just checking"); // reserve space for _segmap if (!_segmap.initialize(align_to_allocation_size(_number_of_reserved_segments), align_to_allocation_size(_number_of_committed_segments))) { return false; } MemTracker::record_virtual_memory_type((address)_segmap.low_boundary(), mtCode); assert(_segmap.committed_size() >= (size_t) _number_of_committed_segments, "could not commit enough space for segment map"); assert(_segmap.reserved_size() >= (size_t) _number_of_reserved_segments , "could not reserve enough space for segment map"); assert(_segmap.reserved_size() >= _segmap.committed_size() , "just checking"); // initialize remaining instance variables clear(); return true; } void CodeHeap::release() { Unimplemented(); } bool CodeHeap::expand_by(size_t size) { // expand _memory space size_t dm = align_to_page_size(_memory.committed_size() + size) - _memory.committed_size(); if (dm > 0) { char* base = _memory.low() + _memory.committed_size(); if (!_memory.expand_by(dm)) return false; on_code_mapping(base, dm); size_t i = _number_of_committed_segments; _number_of_committed_segments = number_of_segments(_memory.committed_size()); assert(_number_of_reserved_segments == number_of_segments(_memory.reserved_size()), "number of reserved segments should not change"); assert(_number_of_reserved_segments >= _number_of_committed_segments, "just checking"); // expand _segmap space size_t ds = align_to_page_size(_number_of_committed_segments) - _segmap.committed_size(); if (ds > 0) { if (!_segmap.expand_by(ds)) return false; } assert(_segmap.committed_size() >= (size_t) _number_of_committed_segments, "just checking"); // initialize additional segmap entries mark_segmap_as_free(i, _number_of_committed_segments); } return true; } void CodeHeap::shrink_by(size_t size) { Unimplemented(); } void CodeHeap::clear() { _next_segment = 0; mark_segmap_as_free(0, _number_of_committed_segments); } void* CodeHeap::allocate(size_t size) { size_t length = number_of_segments(size + sizeof(HeapBlock)); assert(length *_segment_size >= sizeof(FreeBlock), "not enough room for FreeList"); // First check if we can satify request from freelist debug_only(verify()); HeapBlock* block = search_freelist(length); debug_only(if (VerifyCodeCacheOften) verify()); if (block != NULL) { assert(block->length() >= length && block->length() < length + CodeCacheMinBlockLength, "sanity check"); assert(!block->free(), "must be marked free"); #ifdef ASSERT memset((void *)block->allocated_space(), badCodeHeapNewVal, size); #endif return block->allocated_space(); } if (length < CodeCacheMinBlockLength) { length = CodeCacheMinBlockLength; } if (_next_segment + length <= _number_of_committed_segments) { mark_segmap_as_used(_next_segment, _next_segment + length); HeapBlock* b = block_at(_next_segment); b->initialize(length); _next_segment += length; #ifdef ASSERT memset((void *)b->allocated_space(), badCodeHeapNewVal, size); #endif return b->allocated_space(); } else { return NULL; } } void CodeHeap::deallocate(void* p) { assert(p == find_start(p), "illegal deallocation"); // Find start of HeapBlock HeapBlock* b = (((HeapBlock *)p) - 1); assert(b->allocated_space() == p, "sanity check"); #ifdef ASSERT memset((void *)b->allocated_space(), badCodeHeapFreeVal, size(b->length()) - sizeof(HeapBlock)); #endif add_to_freelist(b); debug_only(if (VerifyCodeCacheOften) verify()); } void* CodeHeap::find_start(void* p) const { if (!contains(p)) { return NULL; } size_t i = segment_for(p); address b = (address)_segmap.low(); if (b[i] == 0xFF) { return NULL; } while (b[i] > 0) i -= (int)b[i]; HeapBlock* h = block_at(i); if (h->free()) { return NULL; } return h->allocated_space(); } size_t CodeHeap::alignment_unit() const { // this will be a power of two return _segment_size; } size_t CodeHeap::alignment_offset() const { // The lowest address in any allocated block will be // equal to alignment_offset (mod alignment_unit). return sizeof(HeapBlock) & (_segment_size - 1); } // Finds the next free heapblock. If the current one is free, that it returned void* CodeHeap::next_free(HeapBlock *b) const { // Since free blocks are merged, there is max. on free block // between two used ones if (b != NULL && b->free()) b = next_block(b); assert(b == NULL || !b->free(), "must be in use or at end of heap"); return (b == NULL) ? NULL : b->allocated_space(); } // Returns the first used HeapBlock HeapBlock* CodeHeap::first_block() const { if (_next_segment > 0) return block_at(0); return NULL; } HeapBlock *CodeHeap::block_start(void *q) const { HeapBlock* b = (HeapBlock*)find_start(q); if (b == NULL) return NULL; return b - 1; } // Returns the next Heap block an offset into one HeapBlock* CodeHeap::next_block(HeapBlock *b) const { if (b == NULL) return NULL; size_t i = segment_for(b) + b->length(); if (i < _next_segment) return block_at(i); return NULL; } // Returns current capacity size_t CodeHeap::capacity() const { return _memory.committed_size(); } size_t CodeHeap::max_capacity() const { return _memory.reserved_size(); } size_t CodeHeap::allocated_capacity() const { // Start with the committed size in _memory; size_t l = _memory.committed_size(); // Subtract the committed, but unused, segments l -= size(_number_of_committed_segments - _next_segment); // Subtract the size of the freelist l -= size(_free_segments); return l; } size_t CodeHeap::largest_free_block() const { // First check unused space excluding free blocks. size_t free_sz = size(_free_segments); size_t unused = max_capacity() - allocated_capacity() - free_sz; if (unused >= free_sz) return unused; // Now check largest free block. size_t len = 0; for (FreeBlock* b = _freelist; b != NULL; b = b->link()) { if (b->length() > len) len = b->length(); } return MAX2(unused, size(len)); } // Free list management FreeBlock *CodeHeap::following_block(FreeBlock *b) { return (FreeBlock*)(((address)b) + _segment_size * b->length()); } // Inserts block b after a void CodeHeap::insert_after(FreeBlock* a, FreeBlock* b) { assert(a != NULL && b != NULL, "must be real pointers"); // Link b into the list after a b->set_link(a->link()); a->set_link(b); // See if we can merge blocks merge_right(b); // Try to make b bigger merge_right(a); // Try to make a include b } // Try to merge this block with the following block void CodeHeap::merge_right(FreeBlock *a) { assert(a->free(), "must be a free block"); if (following_block(a) == a->link()) { assert(a->link() != NULL && a->link()->free(), "must be free too"); // Update block a to include the following block a->set_length(a->length() + a->link()->length()); a->set_link(a->link()->link()); // Update find_start map size_t beg = segment_for(a); mark_segmap_as_used(beg, beg + a->length()); } } void CodeHeap::add_to_freelist(HeapBlock *a) { FreeBlock* b = (FreeBlock*)a; assert(b != _freelist, "cannot be removed twice"); // Mark as free and update free space count _free_segments += b->length(); b->set_free(); // First element in list? if (_freelist == NULL) { _freelist = b; b->set_link(NULL); return; } // Scan for right place to put into list. List // is sorted by increasing addresseses FreeBlock* prev = NULL; FreeBlock* cur = _freelist; while(cur != NULL && cur < b) { assert(prev == NULL || prev < cur, "must be ordered"); prev = cur; cur = cur->link(); } assert( (prev == NULL && b < _freelist) || (prev < b && (cur == NULL || b < cur)), "list must be ordered"); if (prev == NULL) { // Insert first in list b->set_link(_freelist); _freelist = b; merge_right(_freelist); } else { insert_after(prev, b); } } // Search freelist for an entry on the list with the best fit // Return NULL if no one was found FreeBlock* CodeHeap::search_freelist(size_t length) { FreeBlock *best_block = NULL; FreeBlock *best_prev = NULL; size_t best_length = 0; // Search for smallest block which is bigger than length FreeBlock *prev = NULL; FreeBlock *cur = _freelist; while(cur != NULL) { size_t l = cur->length(); if (l >= length && (best_block == NULL || best_length > l)) { // Remember best block, its previous element, and its length best_block = cur; best_prev = prev; best_length = best_block->length(); } // Next element in list prev = cur; cur = cur->link(); } if (best_block == NULL) { // None found return NULL; } assert((best_prev == NULL && _freelist == best_block ) || (best_prev != NULL && best_prev->link() == best_block), "sanity check"); // Exact (or at least good enough) fit. Remove from list. // Don't leave anything on the freelist smaller than CodeCacheMinBlockLength. if (best_length < length + CodeCacheMinBlockLength) { length = best_length; if (best_prev == NULL) { assert(_freelist == best_block, "sanity check"); _freelist = _freelist->link(); } else { // Unmap element best_prev->set_link(best_block->link()); } } else { // Truncate block and return a pointer to the following block best_block->set_length(best_length - length); best_block = following_block(best_block); // Set used bit and length on new block size_t beg = segment_for(best_block); mark_segmap_as_used(beg, beg + length); best_block->set_length(length); } best_block->set_used(); _free_segments -= length; return best_block; } //---------------------------------------------------------------------------- // Non-product code #ifndef PRODUCT void CodeHeap::print() { tty->print_cr("The Heap"); } #endif void CodeHeap::verify() { // Count the number of blocks on the freelist, and the amount of space // represented. int count = 0; size_t len = 0; for(FreeBlock* b = _freelist; b != NULL; b = b->link()) { len += b->length(); count++; } // Verify that freelist contains the right amount of free space // guarantee(len == _free_segments, "wrong freelist"); // Verify that the number of free blocks is not out of hand. static int free_block_threshold = 10000; if (count > free_block_threshold) { warning("CodeHeap: # of free blocks > %d", free_block_threshold); // Double the warning limit free_block_threshold *= 2; } // Verify that the freelist contains the same number of free blocks that is // found on the full list. for(HeapBlock *h = first_block(); h != NULL; h = next_block(h)) { if (h->free()) count--; } // guarantee(count == 0, "missing free blocks"); }