duke@435: /*
mikael@4153:  * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
duke@435:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435:  *
duke@435:  * This code is free software; you can redistribute it and/or modify it
duke@435:  * under the terms of the GNU General Public License version 2 only, as
duke@435:  * published by the Free Software Foundation.
duke@435:  *
duke@435:  * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
duke@435:  * version 2 for more details (a copy is included in the LICENSE file that
duke@435:  * accompanied this code).
duke@435:  *
duke@435:  * You should have received a copy of the GNU General Public License version
duke@435:  * 2 along with this work; if not, write to the Free Software Foundation,
duke@435:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435:  *
trims@1907:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907:  * or visit www.oracle.com if you need additional information or have any
trims@1907:  * questions.
duke@435:  *
duke@435:  */
duke@435: 
stefank@2314: #include "precompiled.hpp"
stefank@2314: #include "memory/heap.hpp"
stefank@2314: #include "oops/oop.inline.hpp"
stefank@2314: #include "runtime/os.hpp"
zgu@3900: #include "services/memTracker.hpp"
duke@435: 
duke@435: size_t CodeHeap::header_size() {
duke@435:   return sizeof(HeapBlock);
duke@435: }
duke@435: 
duke@435: 
duke@435: // Implementation of Heap
duke@435: 
duke@435: CodeHeap::CodeHeap() {
duke@435:   _number_of_committed_segments = 0;
duke@435:   _number_of_reserved_segments  = 0;
duke@435:   _segment_size                 = 0;
duke@435:   _log2_segment_size            = 0;
duke@435:   _next_segment                 = 0;
duke@435:   _freelist                     = NULL;
neliasso@4952:   _freelist_segments            = 0;
duke@435: }
duke@435: 
duke@435: 
duke@435: void CodeHeap::mark_segmap_as_free(size_t beg, size_t end) {
duke@435:   assert(0   <= beg && beg <  _number_of_committed_segments, "interval begin out of bounds");
duke@435:   assert(beg <  end && end <= _number_of_committed_segments, "interval end   out of bounds");
duke@435:   // setup _segmap pointers for faster indexing
duke@435:   address p = (address)_segmap.low() + beg;
duke@435:   address q = (address)_segmap.low() + end;
duke@435:   // initialize interval
duke@435:   while (p < q) *p++ = 0xFF;
duke@435: }
duke@435: 
duke@435: 
duke@435: void CodeHeap::mark_segmap_as_used(size_t beg, size_t end) {
duke@435:   assert(0   <= beg && beg <  _number_of_committed_segments, "interval begin out of bounds");
duke@435:   assert(beg <  end && end <= _number_of_committed_segments, "interval end   out of bounds");
duke@435:   // setup _segmap pointers for faster indexing
duke@435:   address p = (address)_segmap.low() + beg;
duke@435:   address q = (address)_segmap.low() + end;
duke@435:   // initialize interval
duke@435:   int i = 0;
duke@435:   while (p < q) {
duke@435:     *p++ = i++;
duke@435:     if (i == 0xFF) i = 1;
duke@435:   }
duke@435: }
duke@435: 
duke@435: 
duke@435: static size_t align_to_page_size(size_t size) {
duke@435:   const size_t alignment = (size_t)os::vm_page_size();
duke@435:   assert(is_power_of_2(alignment), "no kidding ???");
duke@435:   return (size + alignment - 1) & ~(alignment - 1);
duke@435: }
duke@435: 
duke@435: 
duke@435: void CodeHeap::on_code_mapping(char* base, size_t size) {
duke@435: #ifdef LINUX
duke@435:   extern void linux_wrap_code(char* base, size_t size);
duke@435:   linux_wrap_code(base, size);
duke@435: #endif
duke@435: }
duke@435: 
duke@435: 
duke@435: bool CodeHeap::reserve(size_t reserved_size, size_t committed_size,
duke@435:                        size_t segment_size) {
duke@435:   assert(reserved_size >= committed_size, "reserved < committed");
duke@435:   assert(segment_size >= sizeof(FreeBlock), "segment size is too small");
duke@435:   assert(is_power_of_2(segment_size), "segment_size must be a power of 2");
duke@435: 
duke@435:   _segment_size      = segment_size;
duke@435:   _log2_segment_size = exact_log2(segment_size);
duke@435: 
duke@435:   // Reserve and initialize space for _memory.
jcoomes@514:   const size_t page_size = os::can_execute_large_page_memory() ?
jcoomes@514:           os::page_size_for_region(committed_size, reserved_size, 8) :
jcoomes@514:           os::vm_page_size();
duke@435:   const size_t granularity = os::vm_allocation_granularity();
duke@435:   const size_t r_align = MAX2(page_size, granularity);
duke@435:   const size_t r_size = align_size_up(reserved_size, r_align);
duke@435:   const size_t c_size = align_size_up(committed_size, page_size);
duke@435: 
duke@435:   const size_t rs_align = page_size == (size_t) os::vm_page_size() ? 0 :
duke@435:     MAX2(page_size, granularity);
coleenp@1091:   ReservedCodeSpace rs(r_size, rs_align, rs_align > 0);
duke@435:   os::trace_page_sizes("code heap", committed_size, reserved_size, page_size,
duke@435:                        rs.base(), rs.size());
duke@435:   if (!_memory.initialize(rs, c_size)) {
duke@435:     return false;
duke@435:   }
duke@435: 
duke@435:   on_code_mapping(_memory.low(), _memory.committed_size());
neliasso@4952:   _number_of_committed_segments = size_to_segments(_memory.committed_size());
neliasso@4952:   _number_of_reserved_segments  = size_to_segments(_memory.reserved_size());
duke@435:   assert(_number_of_reserved_segments >= _number_of_committed_segments, "just checking");
duke@435: 
duke@435:   // reserve space for _segmap
duke@435:   if (!_segmap.initialize(align_to_page_size(_number_of_reserved_segments), align_to_page_size(_number_of_committed_segments))) {
duke@435:     return false;
duke@435:   }
zgu@3900: 
zgu@3900:   MemTracker::record_virtual_memory_type((address)_segmap.low_boundary(), mtCode);
zgu@3900: 
duke@435:   assert(_segmap.committed_size() >= (size_t) _number_of_committed_segments, "could not commit  enough space for segment map");
duke@435:   assert(_segmap.reserved_size()  >= (size_t) _number_of_reserved_segments , "could not reserve enough space for segment map");
duke@435:   assert(_segmap.reserved_size()  >= _segmap.committed_size()     , "just checking");
duke@435: 
duke@435:   // initialize remaining instance variables
duke@435:   clear();
duke@435:   return true;
duke@435: }
duke@435: 
duke@435: 
duke@435: void CodeHeap::release() {
duke@435:   Unimplemented();
duke@435: }
duke@435: 
duke@435: 
duke@435: bool CodeHeap::expand_by(size_t size) {
duke@435:   // expand _memory space
duke@435:   size_t dm = align_to_page_size(_memory.committed_size() + size) - _memory.committed_size();
duke@435:   if (dm > 0) {
duke@435:     char* base = _memory.low() + _memory.committed_size();
duke@435:     if (!_memory.expand_by(dm)) return false;
duke@435:     on_code_mapping(base, dm);
duke@435:     size_t i = _number_of_committed_segments;
neliasso@4952:     _number_of_committed_segments = size_to_segments(_memory.committed_size());
neliasso@4952:     assert(_number_of_reserved_segments == size_to_segments(_memory.reserved_size()), "number of reserved segments should not change");
duke@435:     assert(_number_of_reserved_segments >= _number_of_committed_segments, "just checking");
duke@435:     // expand _segmap space
duke@435:     size_t ds = align_to_page_size(_number_of_committed_segments) - _segmap.committed_size();
duke@435:     if (ds > 0) {
duke@435:       if (!_segmap.expand_by(ds)) return false;
duke@435:     }
duke@435:     assert(_segmap.committed_size() >= (size_t) _number_of_committed_segments, "just checking");
duke@435:     // initialize additional segmap entries
duke@435:     mark_segmap_as_free(i, _number_of_committed_segments);
duke@435:   }
duke@435:   return true;
duke@435: }
duke@435: 
duke@435: 
duke@435: void CodeHeap::shrink_by(size_t size) {
duke@435:   Unimplemented();
duke@435: }
duke@435: 
duke@435: 
duke@435: void CodeHeap::clear() {
duke@435:   _next_segment = 0;
duke@435:   mark_segmap_as_free(0, _number_of_committed_segments);
duke@435: }
duke@435: 
duke@435: 
neliasso@4952: void* CodeHeap::allocate(size_t instance_size, bool is_critical) {
neliasso@4952:   size_t number_of_segments = size_to_segments(instance_size + sizeof(HeapBlock));
neliasso@4952:   assert(segments_to_size(number_of_segments) >= sizeof(FreeBlock), "not enough room for FreeList");
duke@435: 
duke@435:   // First check if we can satify request from freelist
duke@435:   debug_only(verify());
neliasso@4952:   HeapBlock* block = search_freelist(number_of_segments, is_critical);
duke@435:   debug_only(if (VerifyCodeCacheOften) verify());
duke@435:   if (block != NULL) {
neliasso@4952:     assert(block->length() >= number_of_segments && block->length() < number_of_segments + CodeCacheMinBlockLength, "sanity check");
duke@435:     assert(!block->free(), "must be marked free");
duke@435: #ifdef ASSERT
neliasso@4952:     memset((void *)block->allocated_space(), badCodeHeapNewVal, instance_size);
duke@435: #endif
duke@435:     return block->allocated_space();
duke@435:   }
duke@435: 
neliasso@4952:   // Ensure minimum size for allocation to the heap.
neliasso@4952:   if (number_of_segments < CodeCacheMinBlockLength) {
neliasso@4952:     number_of_segments = CodeCacheMinBlockLength;
duke@435:   }
neliasso@4952: 
neliasso@4952:   if (!is_critical) {
neliasso@4952:     // Make sure the allocation fits in the unallocated heap without using
neliasso@4952:     // the CodeCacheMimimumFreeSpace that is reserved for critical allocations.
neliasso@4952:     if (segments_to_size(number_of_segments) > (heap_unallocated_capacity() - CodeCacheMinimumFreeSpace)) {
neliasso@4952:       // Fail allocation
neliasso@4952:       return NULL;
neliasso@4952:     }
neliasso@4952:   }
neliasso@4952: 
neliasso@4952:   if (_next_segment + number_of_segments <= _number_of_committed_segments) {
neliasso@4952:     mark_segmap_as_used(_next_segment, _next_segment + number_of_segments);
duke@435:     HeapBlock* b =  block_at(_next_segment);
neliasso@4952:     b->initialize(number_of_segments);
neliasso@4952:     _next_segment += number_of_segments;
duke@435: #ifdef ASSERT
neliasso@4952:     memset((void *)b->allocated_space(), badCodeHeapNewVal, instance_size);
duke@435: #endif
duke@435:     return b->allocated_space();
duke@435:   } else {
duke@435:     return NULL;
duke@435:   }
duke@435: }
duke@435: 
duke@435: 
duke@435: void CodeHeap::deallocate(void* p) {
duke@435:   assert(p == find_start(p), "illegal deallocation");
duke@435:   // Find start of HeapBlock
duke@435:   HeapBlock* b = (((HeapBlock *)p) - 1);
duke@435:   assert(b->allocated_space() == p, "sanity check");
duke@435: #ifdef ASSERT
duke@435:   memset((void *)b->allocated_space(),
duke@435:          badCodeHeapFreeVal,
neliasso@4952:          segments_to_size(b->length()) - sizeof(HeapBlock));
duke@435: #endif
duke@435:   add_to_freelist(b);
duke@435: 
duke@435:   debug_only(if (VerifyCodeCacheOften) verify());
duke@435: }
duke@435: 
duke@435: 
duke@435: void* CodeHeap::find_start(void* p) const {
duke@435:   if (!contains(p)) {
duke@435:     return NULL;
duke@435:   }
duke@435:   size_t i = segment_for(p);
duke@435:   address b = (address)_segmap.low();
duke@435:   if (b[i] == 0xFF) {
duke@435:     return NULL;
duke@435:   }
duke@435:   while (b[i] > 0) i -= (int)b[i];
duke@435:   HeapBlock* h = block_at(i);
duke@435:   if (h->free()) {
duke@435:     return NULL;
duke@435:   }
duke@435:   return h->allocated_space();
duke@435: }
duke@435: 
duke@435: 
duke@435: size_t CodeHeap::alignment_unit() const {
duke@435:   // this will be a power of two
duke@435:   return _segment_size;
duke@435: }
duke@435: 
duke@435: 
duke@435: size_t CodeHeap::alignment_offset() const {
duke@435:   // The lowest address in any allocated block will be
duke@435:   // equal to alignment_offset (mod alignment_unit).
duke@435:   return sizeof(HeapBlock) & (_segment_size - 1);
duke@435: }
duke@435: 
duke@435: // Finds the next free heapblock. If the current one is free, that it returned
duke@435: void* CodeHeap::next_free(HeapBlock *b) const {
duke@435:   // Since free blocks are merged, there is max. on free block
duke@435:   // between two used ones
duke@435:   if (b != NULL && b->free()) b = next_block(b);
duke@435:   assert(b == NULL || !b->free(), "must be in use or at end of heap");
duke@435:   return (b == NULL) ? NULL : b->allocated_space();
duke@435: }
duke@435: 
duke@435: // Returns the first used HeapBlock
duke@435: HeapBlock* CodeHeap::first_block() const {
duke@435:   if (_next_segment > 0)
duke@435:     return block_at(0);
duke@435:   return NULL;
duke@435: }
duke@435: 
duke@435: HeapBlock *CodeHeap::block_start(void *q) const {
duke@435:   HeapBlock* b = (HeapBlock*)find_start(q);
duke@435:   if (b == NULL) return NULL;
duke@435:   return b - 1;
duke@435: }
duke@435: 
duke@435: // Returns the next Heap block an offset into one
duke@435: HeapBlock* CodeHeap::next_block(HeapBlock *b) const {
duke@435:   if (b == NULL) return NULL;
duke@435:   size_t i = segment_for(b) + b->length();
duke@435:   if (i < _next_segment)
duke@435:     return block_at(i);
duke@435:   return NULL;
duke@435: }
duke@435: 
duke@435: 
duke@435: // Returns current capacity
duke@435: size_t CodeHeap::capacity() const {
duke@435:   return _memory.committed_size();
duke@435: }
duke@435: 
duke@435: size_t CodeHeap::max_capacity() const {
duke@435:   return _memory.reserved_size();
duke@435: }
duke@435: 
duke@435: size_t CodeHeap::allocated_capacity() const {
neliasso@4952:   // size of used heap - size on freelist
neliasso@4952:   return segments_to_size(_next_segment - _freelist_segments);
duke@435: }
duke@435: 
neliasso@4952: // Returns size of the unallocated heap block
neliasso@4952: size_t CodeHeap::heap_unallocated_capacity() const {
neliasso@4952:   // Total number of segments - number currently used
neliasso@4952:   return segments_to_size(_number_of_reserved_segments - _next_segment);
kvn@2414: }
kvn@2414: 
duke@435: // Free list management
duke@435: 
duke@435: FreeBlock *CodeHeap::following_block(FreeBlock *b) {
duke@435:   return (FreeBlock*)(((address)b) + _segment_size * b->length());
duke@435: }
duke@435: 
duke@435: // Inserts block b after a
duke@435: void CodeHeap::insert_after(FreeBlock* a, FreeBlock* b) {
duke@435:   assert(a != NULL && b != NULL, "must be real pointers");
duke@435: 
duke@435:   // Link b into the list after a
duke@435:   b->set_link(a->link());
duke@435:   a->set_link(b);
duke@435: 
duke@435:   // See if we can merge blocks
duke@435:   merge_right(b); // Try to make b bigger
duke@435:   merge_right(a); // Try to make a include b
duke@435: }
duke@435: 
duke@435: // Try to merge this block with the following block
duke@435: void CodeHeap::merge_right(FreeBlock *a) {
duke@435:   assert(a->free(), "must be a free block");
duke@435:   if (following_block(a) == a->link()) {
duke@435:     assert(a->link() != NULL && a->link()->free(), "must be free too");
duke@435:     // Update block a to include the following block
duke@435:     a->set_length(a->length() + a->link()->length());
duke@435:     a->set_link(a->link()->link());
duke@435:     // Update find_start map
duke@435:     size_t beg = segment_for(a);
duke@435:     mark_segmap_as_used(beg, beg + a->length());
duke@435:   }
duke@435: }
duke@435: 
duke@435: void CodeHeap::add_to_freelist(HeapBlock *a) {
duke@435:   FreeBlock* b = (FreeBlock*)a;
duke@435:   assert(b != _freelist, "cannot be removed twice");
duke@435: 
duke@435:   // Mark as free and update free space count
neliasso@4952:   _freelist_segments += b->length();
duke@435:   b->set_free();
duke@435: 
duke@435:   // First element in list?
duke@435:   if (_freelist == NULL) {
duke@435:     _freelist = b;
duke@435:     b->set_link(NULL);
duke@435:     return;
duke@435:   }
duke@435: 
duke@435:   // Scan for right place to put into list. List
duke@435:   // is sorted by increasing addresseses
duke@435:   FreeBlock* prev = NULL;
duke@435:   FreeBlock* cur  = _freelist;
duke@435:   while(cur != NULL && cur < b) {
duke@435:     assert(prev == NULL || prev < cur, "must be ordered");
duke@435:     prev = cur;
duke@435:     cur  = cur->link();
duke@435:   }
duke@435: 
duke@435:   assert( (prev == NULL && b < _freelist) ||
duke@435:           (prev < b && (cur == NULL || b < cur)), "list must be ordered");
duke@435: 
duke@435:   if (prev == NULL) {
duke@435:     // Insert first in list
duke@435:     b->set_link(_freelist);
duke@435:     _freelist = b;
duke@435:     merge_right(_freelist);
duke@435:   } else {
duke@435:     insert_after(prev, b);
duke@435:   }
duke@435: }
duke@435: 
duke@435: // Search freelist for an entry on the list with the best fit
duke@435: // Return NULL if no one was found
neliasso@4952: FreeBlock* CodeHeap::search_freelist(size_t length, bool is_critical) {
duke@435:   FreeBlock *best_block = NULL;
duke@435:   FreeBlock *best_prev  = NULL;
duke@435:   size_t best_length = 0;
duke@435: 
duke@435:   // Search for smallest block which is bigger than length
duke@435:   FreeBlock *prev = NULL;
duke@435:   FreeBlock *cur = _freelist;
duke@435:   while(cur != NULL) {
duke@435:     size_t l = cur->length();
duke@435:     if (l >= length && (best_block == NULL || best_length > l)) {
neliasso@4952: 
neliasso@4952:       // Non critical allocations are not allowed to use the last part of the code heap.
neliasso@4952:       if (!is_critical) {
neliasso@4952:         // Make sure the end of the allocation doesn't cross into the last part of the code heap
neliasso@4952:         if (((size_t)cur + length) > ((size_t)high_boundary() - CodeCacheMinimumFreeSpace)) {
neliasso@4952:           // the freelist is sorted by address - if one fails, all consecutive will also fail.
neliasso@4952:           break;
neliasso@4952:         }
neliasso@4952:       }
neliasso@4952: 
duke@435:       // Remember best block, its previous element, and its length
duke@435:       best_block = cur;
duke@435:       best_prev  = prev;
duke@435:       best_length = best_block->length();
duke@435:     }
duke@435: 
duke@435:     // Next element in list
duke@435:     prev = cur;
duke@435:     cur  = cur->link();
duke@435:   }
duke@435: 
duke@435:   if (best_block == NULL) {
duke@435:     // None found
duke@435:     return NULL;
duke@435:   }
duke@435: 
duke@435:   assert((best_prev == NULL && _freelist == best_block ) ||
duke@435:          (best_prev != NULL && best_prev->link() == best_block), "sanity check");
duke@435: 
duke@435:   // Exact (or at least good enough) fit. Remove from list.
duke@435:   // Don't leave anything on the freelist smaller than CodeCacheMinBlockLength.
duke@435:   if (best_length < length + CodeCacheMinBlockLength) {
duke@435:     length = best_length;
duke@435:     if (best_prev == NULL) {
duke@435:       assert(_freelist == best_block, "sanity check");
duke@435:       _freelist = _freelist->link();
duke@435:     } else {
duke@435:       // Unmap element
duke@435:       best_prev->set_link(best_block->link());
duke@435:     }
duke@435:   } else {
duke@435:     // Truncate block and return a pointer to the following block
duke@435:     best_block->set_length(best_length - length);
duke@435:     best_block = following_block(best_block);
duke@435:     // Set used bit and length on new block
duke@435:     size_t beg = segment_for(best_block);
duke@435:     mark_segmap_as_used(beg, beg + length);
duke@435:     best_block->set_length(length);
duke@435:   }
duke@435: 
duke@435:   best_block->set_used();
neliasso@4952:   _freelist_segments -= length;
duke@435:   return best_block;
duke@435: }
duke@435: 
duke@435: //----------------------------------------------------------------------------
duke@435: // Non-product code
duke@435: 
duke@435: #ifndef PRODUCT
duke@435: 
duke@435: void CodeHeap::print() {
duke@435:   tty->print_cr("The Heap");
duke@435: }
duke@435: 
duke@435: #endif
duke@435: 
duke@435: void CodeHeap::verify() {
duke@435:   // Count the number of blocks on the freelist, and the amount of space
duke@435:   // represented.
duke@435:   int count = 0;
duke@435:   size_t len = 0;
duke@435:   for(FreeBlock* b = _freelist; b != NULL; b = b->link()) {
duke@435:     len += b->length();
duke@435:     count++;
duke@435:   }
duke@435: 
duke@435:   // Verify that freelist contains the right amount of free space
neliasso@4952:   //  guarantee(len == _freelist_segments, "wrong freelist");
duke@435: 
duke@435:   // Verify that the number of free blocks is not out of hand.
duke@435:   static int free_block_threshold = 10000;
duke@435:   if (count > free_block_threshold) {
duke@435:     warning("CodeHeap: # of free blocks > %d", free_block_threshold);
duke@435:     // Double the warning limit
duke@435:     free_block_threshold *= 2;
duke@435:   }
duke@435: 
duke@435:   // Verify that the freelist contains the same number of free blocks that is
duke@435:   // found on the full list.
duke@435:   for(HeapBlock *h = first_block(); h != NULL; h = next_block(h)) {
duke@435:     if (h->free()) count--;
duke@435:   }
phh@1558:   //  guarantee(count == 0, "missing free blocks");
duke@435: }