jdk

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/*
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 * Copyright (c) 2016, 2023, Oracle and/or its affiliates. All rights reserved.
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 *
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 * This code is free software; you can redistribute it and/or modify it
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 * under the terms of the GNU General Public License version 2 only, as
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 * published by the Free Software Foundation.
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 *
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 * This code is distributed in the hope that it will be useful, but WITHOUT
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 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
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 * version 2 for more details (a copy is included in the LICENSE file that
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 * accompanied this code).
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 *
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 * You should have received a copy of the GNU General Public License version
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 * 2 along with this work; if not, write to the Free Software Foundation,
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 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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 *
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 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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 * or visit www.oracle.com if you need additional information or have any
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 * questions.
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 */
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#include "precompiled.hpp"
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#include "gc/shared/memset_with_concurrent_readers.hpp"
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#include "utilities/globalDefinitions.hpp"
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#include "utilities/vmassert_uninstall.hpp"
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#include <iomanip>
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#include <string.h>
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#include <sstream>
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#include "utilities/vmassert_reinstall.hpp"
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#include "unittest.hpp"
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static unsigned line_byte(const char* line, size_t i) {
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  return unsigned(line[i]) & 0xFF;
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}
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TEST(gc, memset_with_concurrent_readers) {
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  const size_t chunk_size = 8 * BytesPerWord;
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  const unsigned chunk_count = 4;
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  const size_t block_size = (chunk_count + 4) * chunk_size;
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  char block[block_size];
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  char clear_block[block_size];
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  char set_block[block_size];
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  // block format:
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  // 0: unused leading chunk
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  // 1: chunk written from start index to end of chunk
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  // ... nchunks fully written chunks
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  // N: chunk written from start of chunk to end index
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  // N+1: unused trailing chunk
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  const int clear_value = 0;
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  const int set_value = 0xAC;
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  memset(clear_block, clear_value, block_size);
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  memset(set_block, set_value, block_size);
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  for (unsigned nchunks = 0; nchunks <= chunk_count; ++nchunks) {
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    for (size_t start = 1; start <= chunk_size; ++start) {
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      for (size_t end = 0; end <= chunk_size; ++end) {
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        size_t set_start = chunk_size + start;
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        size_t set_end = (2 + nchunks) * chunk_size + end;
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        size_t set_size = set_end - set_start;
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        memset(block, clear_value, block_size);
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        memset_with_concurrent_readers(&block[set_start], set_value, set_size);
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        bool head_clear = !memcmp(clear_block, block, set_start);
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        bool middle_set = !memcmp(set_block, block + set_start, set_size);
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        bool tail_clear = !memcmp(clear_block, block + set_end, block_size - set_end);
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        if (!(head_clear && middle_set && tail_clear)) {
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          std::ostringstream err_stream;
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          err_stream << "*** memset_with_concurrent_readers failed: set start "
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                     << set_start << ", set end " << set_end << std::endl;
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          for (unsigned chunk = 0; chunk < (block_size / chunk_size); ++chunk) {
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            for (unsigned line = 0; line < (chunk_size / BytesPerWord); ++line) {
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              const char* lp = &block[chunk * chunk_size + line * BytesPerWord];
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              err_stream << std::dec << chunk << "," << line << ": " << std::hex
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                         << std::setw(2) << line_byte(lp, 0) << " "
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                         << std::setw(2) << line_byte(lp, 1) << "  "
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                         << std::setw(2) << line_byte(lp, 2) << " "
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                         << std::setw(2) << line_byte(lp, 3) << "  "
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                         << std::setw(2) << line_byte(lp, 4) << " "
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                         << std::setw(2) << line_byte(lp, 5) << "  "
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                         << std::setw(2) << line_byte(lp, 6) << " "
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                         << std::setw(2) << line_byte(lp, 7) << std::endl;
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            }
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          }
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          EXPECT_TRUE(head_clear) << "leading byte not clear";
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          EXPECT_TRUE(middle_set) << "memset byte not set";
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          EXPECT_TRUE(tail_clear) << "trailing bye not clear";
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          ASSERT_TRUE(head_clear && middle_set && tail_clear) << err_stream.str();
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        }
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      }
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    }
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  }
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}
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