1 /*
2 * Copyright (c) 2003, 2022, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_UTILITIES_COPY_HPP
26 #define SHARE_UTILITIES_COPY_HPP
27
28 #include "oops/oopsHierarchy.hpp"
29 #include "runtime/atomic.hpp"
30 #include "runtime/globals.hpp"
31 #include "utilities/align.hpp"
32 #include "utilities/bytes.hpp"
33 #include "utilities/debug.hpp"
34 #include "utilities/macros.hpp"
35
36 // Assembly code for platforms that need it.
37 extern "C" {
38 void _Copy_conjoint_words(const HeapWord* from, HeapWord* to, size_t count);
39 void _Copy_disjoint_words(const HeapWord* from, HeapWord* to, size_t count);
40
41 void _Copy_conjoint_jshorts_atomic(const jshort* from, jshort* to, size_t count);
42 void _Copy_conjoint_jints_atomic (const jint* from, jint* to, size_t count);
43 void _Copy_conjoint_jlongs_atomic (const jlong* from, jlong* to, size_t count);
44
45 void _Copy_arrayof_conjoint_bytes (const HeapWord* from, HeapWord* to, size_t count);
46 void _Copy_arrayof_conjoint_jshorts(const HeapWord* from, HeapWord* to, size_t count);
47 void _Copy_arrayof_conjoint_jints (const HeapWord* from, HeapWord* to, size_t count);
48 void _Copy_arrayof_conjoint_jlongs (const HeapWord* from, HeapWord* to, size_t count);
49 }
50
51 class Copy : AllStatic {
52 public:
53 // Block copy methods have four attributes. We don't define all possibilities.
54 // alignment: aligned to BytesPerLong
55 // arrayof: arraycopy operation with both operands aligned on the same
56 // boundary as the first element of an array of the copy unit.
57 // This is currently a HeapWord boundary on all platforms, except
58 // for long and double arrays, which are aligned on an 8-byte
59 // boundary on all platforms.
60 // arraycopy operations are implicitly atomic on each array element.
61 // overlap: disjoint or conjoint.
62 // copy unit: bytes or words (i.e., HeapWords) or oops (i.e., pointers).
63 // atomicity: atomic or non-atomic on the copy unit.
64 //
65 // Names are constructed thusly:
66 //
67 // [ 'aligned_' | 'arrayof_' ]
68 // ('conjoint_' | 'disjoint_')
69 // ('words' | 'bytes' | 'jshorts' | 'jints' | 'jlongs' | 'oops')
70 // [ '_atomic' ]
71 //
72 // Except in the arrayof case, whatever the alignment is, we assume we can copy
73 // whole alignment units. E.g., if BytesPerLong is 2x word alignment, an odd
74 // count may copy an extra word. In the arrayof case, we are allowed to copy
75 // only the number of copy units specified.
76 //
77 // All callees check count for 0.
78 //
79
80 // HeapWords
81
82 // Word-aligned words, conjoint, not atomic on each word
83 static void conjoint_words(const HeapWord* from, HeapWord* to, size_t count) {
84 assert_params_ok(from, to, HeapWordSize);
85 pd_conjoint_words(from, to, count);
86 }
87
88 // Word-aligned words, disjoint, not atomic on each word
89 static void disjoint_words(const HeapWord* from, HeapWord* to, size_t count) {
90 assert_params_ok(from, to, HeapWordSize);
91 assert_disjoint(from, to, count);
92 pd_disjoint_words(from, to, count);
93 }
94
95 // Word-aligned words, disjoint, atomic on each word
96 static void disjoint_words_atomic(const HeapWord* from, HeapWord* to, size_t count) {
97 assert_params_ok(from, to, HeapWordSize);
98 assert_disjoint(from, to, count);
99 pd_disjoint_words_atomic(from, to, count);
100 }
101
102 // Object-aligned words, conjoint, not atomic on each word
103 static void aligned_conjoint_words(const HeapWord* from, HeapWord* to, size_t count) {
104 assert_params_aligned(from, to);
105 pd_aligned_conjoint_words(from, to, count);
106 }
107
108 // Object-aligned words, disjoint, not atomic on each word
109 static void aligned_disjoint_words(const HeapWord* from, HeapWord* to, size_t count) {
110 assert_params_aligned(from, to);
111 assert_disjoint(from, to, count);
112 pd_aligned_disjoint_words(from, to, count);
113 }
114
115 // bytes, jshorts, jints, jlongs, oops
116
117 // bytes, conjoint, not atomic on each byte (not that it matters)
118 static void conjoint_jbytes(const void* from, void* to, size_t count) {
119 pd_conjoint_bytes(from, to, count);
120 }
121
122 // bytes, conjoint, atomic on each byte (not that it matters)
123 static void conjoint_jbytes_atomic(const void* from, void* to, size_t count) {
124 pd_conjoint_bytes(from, to, count);
125 }
126
127 // jshorts, conjoint, atomic on each jshort
128 static void conjoint_jshorts_atomic(const jshort* from, jshort* to, size_t count) {
129 assert_params_ok(from, to, BytesPerShort);
130 pd_conjoint_jshorts_atomic(from, to, count);
131 }
132
133 // jints, conjoint, atomic on each jint
134 static void conjoint_jints_atomic(const jint* from, jint* to, size_t count) {
135 assert_params_ok(from, to, BytesPerInt);
136 pd_conjoint_jints_atomic(from, to, count);
137 }
138
139 // jlongs, conjoint, atomic on each jlong
140 static void conjoint_jlongs_atomic(const jlong* from, jlong* to, size_t count) {
141 assert_params_ok(from, to, BytesPerLong);
142 pd_conjoint_jlongs_atomic(from, to, count);
143 }
144
145 // oops, conjoint, atomic on each oop
146 static void conjoint_oops_atomic(const oop* from, oop* to, size_t count) {
147 assert_params_ok(from, to, BytesPerHeapOop);
148 pd_conjoint_oops_atomic(from, to, count);
149 }
150
151 // overloaded for UseCompressedOops
152 static void conjoint_oops_atomic(const narrowOop* from, narrowOop* to, size_t count) {
153 assert(sizeof(narrowOop) == sizeof(jint), "this cast is wrong");
154 assert_params_ok(from, to, BytesPerInt);
155 pd_conjoint_jints_atomic((const jint*)from, (jint*)to, count);
156 }
157
158 // Copy a span of memory. If the span is an integral number of aligned
159 // longs, words, or ints, copy those units atomically.
160 // The largest atomic transfer unit is 8 bytes, or the largest power
161 // of two which divides all of from, to, and size, whichever is smaller.
162 static void conjoint_memory_atomic(const void* from, void* to, size_t size);
163
164 static void copy_value_content(const void* from, void* to, size_t size);
165
166 // bytes, conjoint array, atomic on each byte (not that it matters)
167 static void arrayof_conjoint_jbytes(const HeapWord* from, HeapWord* to, size_t count) {
168 pd_arrayof_conjoint_bytes(from, to, count);
169 }
170
171 // jshorts, conjoint array, atomic on each jshort
172 static void arrayof_conjoint_jshorts(const HeapWord* from, HeapWord* to, size_t count) {
173 assert_params_ok(from, to, BytesPerShort);
174 pd_arrayof_conjoint_jshorts(from, to, count);
175 }
176
177 // jints, conjoint array, atomic on each jint
178 static void arrayof_conjoint_jints(const HeapWord* from, HeapWord* to, size_t count) {
179 assert_params_ok(from, to, BytesPerInt);
180 pd_arrayof_conjoint_jints(from, to, count);
181 }
182
183 // jlongs, conjoint array, atomic on each jlong
184 static void arrayof_conjoint_jlongs(const HeapWord* from, HeapWord* to, size_t count) {
185 assert_params_ok(from, to, BytesPerLong);
186 pd_arrayof_conjoint_jlongs(from, to, count);
187 }
188
189 // oops, conjoint array, atomic on each oop
190 static void arrayof_conjoint_oops(const HeapWord* from, HeapWord* to, size_t count) {
191 assert_params_ok(from, to, BytesPerHeapOop);
192 pd_arrayof_conjoint_oops(from, to, count);
193 }
194
195 // Known overlap methods
196
197 // Copy word-aligned words from higher to lower addresses, not atomic on each word
198 inline static void conjoint_words_to_lower(const HeapWord* from, HeapWord* to, size_t byte_count) {
199 // byte_count is in bytes to check its alignment
200 assert_params_ok(from, to, HeapWordSize);
201 assert_byte_count_ok(byte_count, HeapWordSize);
202
203 size_t count = align_up(byte_count, HeapWordSize) >> LogHeapWordSize;
204 assert(to <= from || from + count <= to, "do not overwrite source data");
205
206 while (count-- > 0) {
207 *to++ = *from++;
208 }
209 }
210
211 // Copy word-aligned words from lower to higher addresses, not atomic on each word
212 inline static void conjoint_words_to_higher(const HeapWord* from, HeapWord* to, size_t byte_count) {
213 // byte_count is in bytes to check its alignment
214 assert_params_ok(from, to, HeapWordSize);
215 assert_byte_count_ok(byte_count, HeapWordSize);
216 if (byte_count == 0) return;
217
218 size_t count = align_up(byte_count, HeapWordSize) >> LogHeapWordSize;
219 assert(from <= to || to + count <= from, "do not overwrite source data");
220
221 from += count - 1;
222 to += count - 1;
223 while (count-- > 0) {
224 *to-- = *from--;
225 }
226 }
227
228 /**
229 * Copy elements
230 *
231 * @param src address of source
232 * @param dst address of destination
233 * @param byte_count number of bytes to copy
234 * @param elem_size size of the elements to copy-swap
235 */
236 static void conjoint_copy(const void* src, void* dst, size_t byte_count, size_t elem_size);
237
238 /**
239 * Copy and *unconditionally* byte swap elements
240 *
241 * @param src address of source
242 * @param dst address of destination
243 * @param byte_count number of bytes to copy
244 * @param elem_size size of the elements to copy-swap
245 */
246 static void conjoint_swap(const void* src, void* dst, size_t byte_count, size_t elem_size);
247
248 /**
249 * Copy and byte swap elements from the specified endian to the native (cpu) endian if needed (if they differ)
250 *
251 * @param src address of source
252 * @param dst address of destination
253 * @param byte_count number of bytes to copy
254 * @param elem_size size of the elements to copy-swap
255 */
256 template <Endian::Order endian>
257 static void conjoint_swap_if_needed(const void* src, void* dst, size_t byte_count, size_t elem_size) {
258 if (Endian::NATIVE != endian) {
259 conjoint_swap(src, dst, byte_count, elem_size);
260 } else {
261 conjoint_copy(src, dst, byte_count, elem_size);
262 }
263 }
264
265 // Fill methods
266
267 // Fill word-aligned words, not atomic on each word
268 // set_words
269 static void fill_to_words(HeapWord* to, size_t count, juint value = 0) {
270 assert_params_ok(to, HeapWordSize);
271 pd_fill_to_words(to, count, value);
272 }
273
274 static void fill_to_aligned_words(HeapWord* to, size_t count, juint value = 0) {
275 assert_params_aligned(to);
276 pd_fill_to_aligned_words(to, count, value);
277 }
278
279 // Fill bytes
280 static void fill_to_bytes(void* to, size_t count, jubyte value = 0) {
281 pd_fill_to_bytes(to, count, value);
282 }
283
284 // Fill a span of memory. If the span is an integral number of aligned
285 // longs, words, or ints, store to those units atomically.
286 // The largest atomic transfer unit is 8 bytes, or the largest power
287 // of two which divides both to and size, whichever is smaller.
288 static void fill_to_memory_atomic(void* to, size_t size, jubyte value = 0);
289
290 // Zero-fill methods
291
292 // Zero word-aligned words, not atomic on each word
293 static void zero_to_words(HeapWord* to, size_t count) {
294 assert_params_ok(to, HeapWordSize);
295 pd_zero_to_words(to, count);
296 }
297
298 // Zero bytes
299 static void zero_to_bytes(void* to, size_t count) {
300 pd_zero_to_bytes(to, count);
301 }
302
303 protected:
304 inline static void shared_disjoint_words_atomic(const HeapWord* from,
305 HeapWord* to, size_t count) {
306
307 switch (count) {
308 case 8: Atomic::store(&to[7], Atomic::load(&from[7]));
309 case 7: Atomic::store(&to[6], Atomic::load(&from[6]));
310 case 6: Atomic::store(&to[5], Atomic::load(&from[5]));
311 case 5: Atomic::store(&to[4], Atomic::load(&from[4]));
312 case 4: Atomic::store(&to[3], Atomic::load(&from[3]));
313 case 3: Atomic::store(&to[2], Atomic::load(&from[2]));
314 case 2: Atomic::store(&to[1], Atomic::load(&from[1]));
315 case 1: Atomic::store(&to[0], Atomic::load(&from[0]));
316 case 0: break;
317 default:
318 while (count-- > 0) {
319 Atomic::store(to++, Atomic::load(from++));
320 }
321 break;
322 }
323 }
324
325 private:
326 static bool params_disjoint(const HeapWord* from, HeapWord* to, size_t count) {
327 if (from < to) {
328 return pointer_delta(to, from) >= count;
329 }
330 return pointer_delta(from, to) >= count;
331 }
332
333 // These methods raise a fatal if they detect a problem.
334
335 static void assert_disjoint(const HeapWord* from, HeapWord* to, size_t count) {
336 assert(params_disjoint(from, to, count), "source and dest overlap");
337 }
338
339 static void assert_params_ok(const void* from, void* to, intptr_t alignment) {
340 assert(is_aligned(from, alignment), "must be aligned: " PTR_FORMAT, p2i(from));
341 assert(is_aligned(to, alignment), "must be aligned: " PTR_FORMAT, p2i(to));
342 }
343
344 static void assert_params_ok(HeapWord* to, intptr_t alignment) {
345 assert(is_aligned(to, alignment), "must be aligned: " PTR_FORMAT, p2i(to));
346 }
347
348 static void assert_params_aligned(const HeapWord* from, HeapWord* to) {
349 assert(is_aligned(from, BytesPerLong), "must be aligned: " PTR_FORMAT, p2i(from));
350 assert(is_aligned(to, BytesPerLong), "must be aligned: " PTR_FORMAT, p2i(to));
351 }
352
353 static void assert_params_aligned(HeapWord* to) {
354 assert(is_aligned(to, BytesPerLong), "must be aligned: " PTR_FORMAT, p2i(to));
355 }
356
357 static void assert_byte_count_ok(size_t byte_count, size_t unit_size) {
358 assert(is_aligned(byte_count, unit_size), "byte count must be aligned");
359 }
360
361 // Platform dependent implementations of the above methods.
362 #include CPU_HEADER(copy)
363
364 };
365
366 #endif // SHARE_UTILITIES_COPY_HPP