1/*
2 * Copyright (c) 2016, 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#include "precompiled.hpp"
25#include "gc/shared/memset_with_concurrent_readers.hpp"
26#include "utilities/globalDefinitions.hpp"
27#include "unittest.hpp"
28
29#include <string.h>
30#include <sstream>
31
32static unsigned line_byte(const char* line, size_t i) {
33 return unsigned(line[i]) & 0xFF;
34}
35
36TEST(gc, memset_with_concurrent_readers) {
37 const size_t chunk_size = 8 * BytesPerWord;
38 const unsigned chunk_count = 4;
39 const size_t block_size = (chunk_count + 4) * chunk_size;
40 char block[block_size];
41 char clear_block[block_size];
42 char set_block[block_size];
43
44 // block format:
45 // 0: unused leading chunk
46 // 1: chunk written from start index to end of chunk
47 // ... nchunks fully written chunks
48 // N: chunk written from start of chunk to end index
49 // N+1: unused trailing chunk
50
51 const int clear_value = 0;
52 const int set_value = 0xAC;
53
54 memset(clear_block, clear_value, block_size);
55 memset(set_block, set_value, block_size);
56
57 for (unsigned nchunks = 0; nchunks <= chunk_count; ++nchunks) {
58 for (size_t start = 1; start <= chunk_size; ++start) {
59 for (size_t end = 0; end <= chunk_size; ++end) {
60 size_t set_start = chunk_size + start;
61 size_t set_end = (2 + nchunks) * chunk_size + end;
62 size_t set_size = set_end - set_start;
63
64 memset(block, clear_value, block_size);
65 memset_with_concurrent_readers(&block[set_start], set_value, set_size);
66 bool head_clear = !memcmp(clear_block, block, set_start);
67 bool middle_set = !memcmp(set_block, block + set_start, set_size);
68 bool tail_clear = !memcmp(clear_block, block + set_end, block_size - set_end);
69 if (!(head_clear && middle_set && tail_clear)) {
70 std::ostringstream err_stream;
71 err_stream << "*** memset_with_concurrent_readers failed: set start "
72 << set_start << ", set end " << set_end << std::endl;
73 for (unsigned chunk = 0; chunk < (block_size / chunk_size); ++chunk) {
74 for (unsigned line = 0; line < (chunk_size / BytesPerWord); ++line) {
75
76 const char* lp = &block[chunk * chunk_size + line * BytesPerWord];
77
78 err_stream << std::dec << chunk << "," << line << ": " << std::hex
79 << std::setw(2) << line_byte(lp, 0) << " "
80 << std::setw(2) << line_byte(lp, 1) << " "
81 << std::setw(2) << line_byte(lp, 2) << " "
82 << std::setw(2) << line_byte(lp, 3) << " "
83 << std::setw(2) << line_byte(lp, 4) << " "
84 << std::setw(2) << line_byte(lp, 5) << " "
85 << std::setw(2) << line_byte(lp, 6) << " "
86 << std::setw(2) << line_byte(lp, 7) << std::endl;
87 }
88 }
89 EXPECT_TRUE(head_clear) << "leading byte not clear";
90 EXPECT_TRUE(middle_set) << "memset byte not set";
91 EXPECT_TRUE(tail_clear) << "trailing bye not clear";
92 ASSERT_TRUE(head_clear && middle_set && tail_clear) << err_stream.str();
93 }
94 }
95 }
96 }
97}
98