jdk-sandbox: comparison hotspot/src/share/vm/memory/heap.cpp

equal deleted inserted replaced

-:92390f57e8b1
+:78b1c3670525
 _number_of_reserved_segments  = 0;
 _segment_size                 = 0;
 _log2_segment_size            = 0;
 _next_segment                 = 0;
 _freelist                     = NULL;
-_free_segments                = 0;
+_freelist_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");
 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_committed_segments = size_to_segments(_memory.committed_size());
-_number_of_reserved_segments  = number_of_segments(_memory.reserved_size());
+_number_of_reserved_segments  = size_to_segments(_memory.reserved_size());
 assert(_number_of_reserved_segments >= _number_of_committed_segments, "just checking");
 // reserve space for _segmap
 if (!_segmap.initialize(align_to_page_size(_number_of_reserved_segments), align_to_page_size(_number_of_committed_segments))) {
 return false;
 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());
+_number_of_committed_segments = size_to_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 == size_to_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;
 _next_segment = 0;
 mark_segmap_as_free(0, _number_of_committed_segments);
 }
-void* CodeHeap::allocate(size_t size) {
+void* CodeHeap::allocate(size_t instance_size, bool is_critical) {
-size_t length = number_of_segments(size + sizeof(HeapBlock));
+size_t number_of_segments = size_to_segments(instance_size + sizeof(HeapBlock));
-assert(length *_segment_size >= sizeof(FreeBlock), "not enough room for FreeList");
+assert(segments_to_size(number_of_segments) >= sizeof(FreeBlock), "not enough room for FreeList");
 // First check if we can satify request from freelist
 debug_only(verify());
-HeapBlock* block = search_freelist(length);
+HeapBlock* block = search_freelist(number_of_segments, is_critical);
 debug_only(if (VerifyCodeCacheOften) verify());
 if (block != NULL) {
-assert(block->length() >= length && block->length() < length + CodeCacheMinBlockLength, "sanity check");
+assert(block->length() >= number_of_segments && block->length() < number_of_segments + CodeCacheMinBlockLength, "sanity check");
 assert(!block->free(), "must be marked free");
 #ifdef ASSERT
-memset((void *)block->allocated_space(), badCodeHeapNewVal, size);
+memset((void *)block->allocated_space(), badCodeHeapNewVal, instance_size);
 #endif
 return block->allocated_space();
 }
-if (length < CodeCacheMinBlockLength) {
+// Ensure minimum size for allocation to the heap.
-length = CodeCacheMinBlockLength;
+if (number_of_segments < CodeCacheMinBlockLength) {
-}
+number_of_segments = CodeCacheMinBlockLength;
-if (_next_segment + length <= _number_of_committed_segments) {
+}
-mark_segmap_as_used(_next_segment, _next_segment + length);
+if (!is_critical) {
+// Make sure the allocation fits in the unallocated heap without using
+// the CodeCacheMimimumFreeSpace that is reserved for critical allocations.
+if (segments_to_size(number_of_segments) > (heap_unallocated_capacity() - CodeCacheMinimumFreeSpace)) {
+// Fail allocation
+return NULL;
+}
+}
+if (_next_segment + number_of_segments <= _number_of_committed_segments) {
+mark_segmap_as_used(_next_segment, _next_segment + number_of_segments);
 HeapBlock* b =  block_at(_next_segment);
-b->initialize(length);
+b->initialize(number_of_segments);
-_next_segment += length;
+_next_segment += number_of_segments;
 #ifdef ASSERT
-memset((void *)b->allocated_space(), badCodeHeapNewVal, size);
+memset((void *)b->allocated_space(), badCodeHeapNewVal, instance_size);
 #endif
 return b->allocated_space();
 } else {
 return NULL;
 }
 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));
+segments_to_size(b->length()) - sizeof(HeapBlock));
 #endif
 add_to_freelist(b);
 debug_only(if (VerifyCodeCacheOften) verify());
 }
 size_t CodeHeap::max_capacity() const {
 return _memory.reserved_size();
 }
 size_t CodeHeap::allocated_capacity() const {
-// Start with the committed size in _memory;
+// size of used heap - size on freelist
-size_t l = _memory.committed_size();
+return segments_to_size(_next_segment - _freelist_segments);
+}
-// Subtract the committed, but unused, segments
-l -= size(_number_of_committed_segments - _next_segment);
+// Returns size of the unallocated heap block
+size_t CodeHeap::heap_unallocated_capacity() const {
-// Subtract the size of the freelist
+// Total number of segments - number currently used
-l -= size(_free_segments);
+return segments_to_size(_number_of_reserved_segments - _next_segment);
-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) {
 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();
+_freelist_segments += b->length();
 b->set_free();
 // First element in list?
 if (_freelist == NULL) {
 _freelist = 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* CodeHeap::search_freelist(size_t length, bool is_critical) {
 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)) {
+// Non critical allocations are not allowed to use the last part of the code heap.
+if (!is_critical) {
+// Make sure the end of the allocation doesn't cross into the last part of the code heap
+if (((size_t)cur + length) > ((size_t)high_boundary() - CodeCacheMinimumFreeSpace)) {
+// the freelist is sorted by address - if one fails, all consecutive will also fail.
+break;
+}
+}
 // Remember best block, its previous element, and its length
 best_block = cur;
 best_prev  = prev;
 best_length = best_block->length();
 }
 mark_segmap_as_used(beg, beg + length);
 best_block->set_length(length);
 }
 best_block->set_used();
-_free_segments -= length;
+_freelist_segments -= length;
 return best_block;
 }
 //----------------------------------------------------------------------------
 // Non-product code
 len += b->length();
 count++;
 }
 // Verify that freelist contains the right amount of free space
-//  guarantee(len == _free_segments, "wrong freelist");
+//  guarantee(len == _freelist_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);

changeset 17016	78b1c3670525
parent 16670	4af09aff4237
child 19319	0ad35be0733a