Mercurial > hg > truffle
diff src/share/vm/gc_interface/collectedHeap.cpp @ 481:7d7a7c599c17
6578152: fill_region_with_object has usability and safety issues
Reviewed-by: apetrusenko, ysr
author | jcoomes |
---|---|
date | Thu, 11 Dec 2008 12:05:08 -0800 |
parents | 1ee8caae33af |
children | d593294016c3 |
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--- a/src/share/vm/gc_interface/collectedHeap.cpp Wed Dec 10 23:46:10 2008 -0800 +++ b/src/share/vm/gc_interface/collectedHeap.cpp Thu Dec 11 12:05:08 2008 -0800 @@ -30,12 +30,21 @@ int CollectedHeap::_fire_out_of_memory_count = 0; #endif +size_t CollectedHeap::_filler_array_max_size = 0; + // Memory state functions. -CollectedHeap::CollectedHeap() : - _reserved(), _barrier_set(NULL), _is_gc_active(false), - _total_collections(0), _total_full_collections(0), - _gc_cause(GCCause::_no_gc), _gc_lastcause(GCCause::_no_gc) { +CollectedHeap::CollectedHeap() +{ + const size_t max_len = size_t(arrayOopDesc::max_array_length(T_INT)); + const size_t elements_per_word = HeapWordSize / sizeof(jint); + _filler_array_max_size = align_object_size(filler_array_hdr_size() + + max_len * elements_per_word); + + _barrier_set = NULL; + _is_gc_active = false; + _total_collections = _total_full_collections = 0; + _gc_cause = _gc_lastcause = GCCause::_no_gc; NOT_PRODUCT(_promotion_failure_alot_count = 0;) NOT_PRODUCT(_promotion_failure_alot_gc_number = 0;) @@ -128,6 +137,95 @@ return obj; } +size_t CollectedHeap::filler_array_hdr_size() { + return size_t(arrayOopDesc::header_size(T_INT)); +} + +size_t CollectedHeap::filler_array_min_size() { + return align_object_size(filler_array_hdr_size()); +} + +size_t CollectedHeap::filler_array_max_size() { + return _filler_array_max_size; +} + +#ifdef ASSERT +void CollectedHeap::fill_args_check(HeapWord* start, size_t words) +{ + assert(words >= min_fill_size(), "too small to fill"); + assert(words % MinObjAlignment == 0, "unaligned size"); + assert(Universe::heap()->is_in_reserved(start), "not in heap"); + assert(Universe::heap()->is_in_reserved(start + words - 1), "not in heap"); +} + +void CollectedHeap::zap_filler_array(HeapWord* start, size_t words) +{ + if (ZapFillerObjects) { + Copy::fill_to_words(start + filler_array_hdr_size(), + words - filler_array_hdr_size(), 0XDEAFBABE); + } +} +#endif // ASSERT + +void +CollectedHeap::fill_with_array(HeapWord* start, size_t words) +{ + assert(words >= filler_array_min_size(), "too small for an array"); + assert(words <= filler_array_max_size(), "too big for a single object"); + + const size_t payload_size = words - filler_array_hdr_size(); + const size_t len = payload_size * HeapWordSize / sizeof(jint); + + // Set the length first for concurrent GC. + ((arrayOop)start)->set_length((int)len); + post_allocation_setup_common(Universe::fillerArrayKlassObj(), start, + words); + DEBUG_ONLY(zap_filler_array(start, words);) +} + +void +CollectedHeap::fill_with_object_impl(HeapWord* start, size_t words) +{ + assert(words <= filler_array_max_size(), "too big for a single object"); + + if (words >= filler_array_min_size()) { + fill_with_array(start, words); + } else if (words > 0) { + assert(words == min_fill_size(), "unaligned size"); + post_allocation_setup_common(SystemDictionary::object_klass(), start, + words); + } +} + +void CollectedHeap::fill_with_object(HeapWord* start, size_t words) +{ + DEBUG_ONLY(fill_args_check(start, words);) + HandleMark hm; // Free handles before leaving. + fill_with_object_impl(start, words); +} + +void CollectedHeap::fill_with_objects(HeapWord* start, size_t words) +{ + DEBUG_ONLY(fill_args_check(start, words);) + HandleMark hm; // Free handles before leaving. + +#ifdef LP64 + // A single array can fill ~8G, so multiple objects are needed only in 64-bit. + // First fill with arrays, ensuring that any remaining space is big enough to + // fill. The remainder is filled with a single object. + const size_t min = min_fill_size(); + const size_t max = filler_array_max_size(); + while (words > max) { + const size_t cur = words - max >= min ? max : max - min; + fill_with_array(start, cur); + start += cur; + words -= cur; + } +#endif + + fill_with_object_impl(start, words); +} + oop CollectedHeap::new_store_barrier(oop new_obj) { // %%% This needs refactoring. (It was imported from the server compiler.) guarantee(can_elide_tlab_store_barriers(), "store barrier elision not supported");