Method MultiprocessChild

util/linux/memory_map_test.cc:217–253

  }

  void MultiprocessChild() override {
    auto code_address = FromPointerCast<LinuxVMAddress>(getpid);
    CheckedWriteFile(WritePipeHandle(), &code_address, sizeof(code_address));

    auto stack_address = FromPointerCast<LinuxVMAddress>(&code_address);
    CheckedWriteFile(WritePipeHandle(), &stack_address, sizeof(stack_address));

    ScopedMmap mapping;
    ASSERT_TRUE(mapping.ResetMmap(
        nullptr, page_size_, PROT_NONE, MAP_SHARED | MAP_ANON, -1, 0));
    auto mapped_address = mapping.addr_as<LinuxVMAddress>();
    CheckedWriteFile(
        WritePipeHandle(), &mapped_address, sizeof(mapped_address));

    ScopedTempDir temp_dir;
    base::FilePath path =
        temp_dir.path().Append(FILE_PATH_LITERAL("test_file"));
    ScopedFileHandle handle;
    ASSERT_NO_FATAL_FAILURE(InitializeFile(path, page_size_ * 2, &handle));

    ScopedMmap file_mapping;
    ASSERT_TRUE(file_mapping.ResetMmap(nullptr,
                                       page_size_,
                                       PROT_READ | PROT_WRITE,
                                       MAP_PRIVATE,
                                       handle.get(),
                                       page_size_));

    auto mapped_file_address = file_mapping.addr_as<LinuxVMAddress>();
    CheckedWriteFile(
        WritePipeHandle(), &mapped_file_address, sizeof(mapped_file_address));
    LinuxVMSize path_length = path.value().size();
    CheckedWriteFile(WritePipeHandle(), &path_length, sizeof(path_length));
    CheckedWriteFile(WritePipeHandle(), path.value().c_str(), path_length);

    CheckedReadFileAtEOF(ReadPipeHandle());
  }

  const size_t page_size_;
};