48 // Header size computation. |
48 // Header size computation. |
49 // The header is considered the oop part of this type plus the length. |
49 // The header is considered the oop part of this type plus the length. |
50 // Returns the aligned header_size_in_bytes. This is not equivalent to |
50 // Returns the aligned header_size_in_bytes. This is not equivalent to |
51 // sizeof(arrayOopDesc) which should not appear in the code. |
51 // sizeof(arrayOopDesc) which should not appear in the code. |
52 static int header_size_in_bytes() { |
52 static int header_size_in_bytes() { |
53 size_t hs = align_size_up(length_offset_in_bytes() + sizeof(int), |
53 size_t hs = align_up(length_offset_in_bytes() + sizeof(int), |
54 HeapWordSize); |
54 HeapWordSize); |
55 #ifdef ASSERT |
55 #ifdef ASSERT |
56 // make sure it isn't called before UseCompressedOops is initialized. |
56 // make sure it isn't called before UseCompressedOops is initialized. |
57 static size_t arrayoopdesc_hs = 0; |
57 static size_t arrayoopdesc_hs = 0; |
58 if (arrayoopdesc_hs == 0) arrayoopdesc_hs = hs; |
58 if (arrayoopdesc_hs == 0) arrayoopdesc_hs = hs; |
110 static int32_t max_array_length(BasicType type) { |
110 static int32_t max_array_length(BasicType type) { |
111 assert(type >= 0 && type < T_CONFLICT, "wrong type"); |
111 assert(type >= 0 && type < T_CONFLICT, "wrong type"); |
112 assert(type2aelembytes(type) != 0, "wrong type"); |
112 assert(type2aelembytes(type) != 0, "wrong type"); |
113 |
113 |
114 const size_t max_element_words_per_size_t = |
114 const size_t max_element_words_per_size_t = |
115 align_size_down((SIZE_MAX/HeapWordSize - header_size(type)), MinObjAlignment); |
115 align_down((SIZE_MAX/HeapWordSize - header_size(type)), MinObjAlignment); |
116 const size_t max_elements_per_size_t = |
116 const size_t max_elements_per_size_t = |
117 HeapWordSize * max_element_words_per_size_t / type2aelembytes(type); |
117 HeapWordSize * max_element_words_per_size_t / type2aelembytes(type); |
118 if ((size_t)max_jint < max_elements_per_size_t) { |
118 if ((size_t)max_jint < max_elements_per_size_t) { |
119 // It should be ok to return max_jint here, but parts of the code |
119 // It should be ok to return max_jint here, but parts of the code |
120 // (CollectedHeap, Klass::oop_oop_iterate(), and more) uses an int for |
120 // (CollectedHeap, Klass::oop_oop_iterate(), and more) uses an int for |
121 // passing around the size (in words) of an object. So, we need to avoid |
121 // passing around the size (in words) of an object. So, we need to avoid |
122 // overflowing an int when we add the header. See CRs 4718400 and 7110613. |
122 // overflowing an int when we add the header. See CRs 4718400 and 7110613. |
123 return align_size_down(max_jint - header_size(type), MinObjAlignment); |
123 return align_down(max_jint - header_size(type), MinObjAlignment); |
124 } |
124 } |
125 return (int32_t)max_elements_per_size_t; |
125 return (int32_t)max_elements_per_size_t; |
126 } |
126 } |
127 |
127 |
128 }; |
128 }; |