/*

 * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

#include "precompiled.hpp"

#include "utilities/globalDefinitions.hpp"

#include "unittest.hpp"

static unsigned line_byte(const char* line, size_t i) {

  return unsigned(line[i]) & 0xFF;

}

TEST(gc, memset_with_concurrent_readers) {

  const size_t chunk_size = 8 * BytesPerWord;

  const unsigned chunk_count = 4;

  const size_t block_size = (chunk_count + 4) * chunk_size;

  char block[block_size];

  char clear_block[block_size];

  char set_block[block_size];

  // block format:

  // 0: unused leading chunk

  // 1: chunk written from start index to end of chunk

  // ... nchunks fully written chunks

  // N: chunk written from start of chunk to end index

  // N+1: unused trailing chunk

  const int clear_value = 0;

  const int set_value = 0xAC;

  memset(clear_block, clear_value, block_size);

  memset(set_block, set_value, block_size);

  for (unsigned nchunks = 0; nchunks <= chunk_count; ++nchunks) {

    for (size_t start = 1; start <= chunk_size; ++start) {

      for (size_t end = 0; end <= chunk_size; ++end) {

        size_t set_start = chunk_size + start;

        size_t set_end = (2 + nchunks) * chunk_size + end;

        size_t set_size = set_end - set_start;

        memset(block, clear_value, block_size);

        memset_with_concurrent_readers(&block[set_start], set_value, set_size);

        bool head_clear = !memcmp(clear_block, block, set_start);

        bool middle_set = !memcmp(set_block, block + set_start, set_size);

        bool tail_clear = !memcmp(clear_block, block + set_end, block_size - set_end);

        if (!(head_clear && middle_set && tail_clear)) {

          std::ostringstream err_stream;

          err_stream << "*** memset_with_concurrent_readers failed: set start "

                     << set_start << ", set end " << set_end << std::endl;

          for (unsigned chunk = 0; chunk < (block_size / chunk_size); ++chunk) {

            for (unsigned line = 0; line < (chunk_size / BytesPerWord); ++line) {

              const char* lp = &block[chunk * chunk_size + line * BytesPerWord];

              err_stream << std::dec << chunk << "," << line << ": " << std::hex

                         << std::setw(2) << line_byte(lp, 0) << " "

                         << std::setw(2) << line_byte(lp, 1) << "  "

                         << std::setw(2) << line_byte(lp, 2) << " "

                         << std::setw(2) << line_byte(lp, 3) << "  "

                         << std::setw(2) << line_byte(lp, 4) << " "

                         << std::setw(2) << line_byte(lp, 5) << "  "

                         << std::setw(2) << line_byte(lp, 6) << " "

                         << std::setw(2) << line_byte(lp, 7) << std::endl;

            }

          }

          EXPECT_TRUE(head_clear) << "leading byte not clear";

          EXPECT_TRUE(middle_set) << "memset byte not set";

          EXPECT_TRUE(tail_clear) << "trailing bye not clear";

          ASSERT_TRUE(head_clear && middle_set && tail_clear) << err_stream.str();

        }

      }

    }

  }

}