SóProvas

ID
249448
Banca
CESPE / CEBRASPE
Órgão
DETRAN-ES
Ano
2010
Provas
Disciplina
Sistemas Operacionais
Assuntos

Julgue os próximos itens, relativos a sistemas operacionais.

No Unix, o BSS representa os dados inicializados do segmento de dados em que são armazenadas, por exemplo, as variáveis dos programas, as cadeias de caracteres e os vetores.

Alternativas
Comentários
  • Conceito:
    • O BSS esta no Segmento de Dados, conforme tabela abaixo. 
    • No  Segmento de dados temos dados Pré-Inicializados de (variáveis, arrays e estruturas);

    Program memory

    Address space segment

    Executable file section

    Code

    Text

    Text

    Initialized data

    Data

    Data

    BSS

    Data

    BSS

    Heap

    Data


    Stack

    Stack


     
    Acredito que o real problema da questão seja porque no Segmento de Dados temos apenas Variáveis Estáticas e Dinâmicas GLOBAIS, e modo que foi escrito deu a entender que seriam quaisquer variáveis.
    Fonte:
    • http://www.informit.com/articles/article.aspx?p=173438
    • http://fgiasson.com/articles/memorylayout.txt
    • http://www.linux-tutorial.info/modules.php?name=MContent&pageid=83
    • http://www.boddunan.com/education/22-computer-science/8172-unix--os--part-a.html
    • http://students.cs.unipi.gr/pub/docs/sysadmin-1992-1998/html/v03/i04/a6.htm
    • http://cs.oberlin.edu/~jdonalds/341/lecture05.html
  • O erro da questão está em afirmar que o BSS representa os dados inicializados. Segundo Tanenbaum, o BSS representa os dados não inicializados na área de dados da memória dos processos.

    Rafael Eduardo Barão
    http://www.itnerante.com.br/profile/RafaelBarao
    http://www.provasdeti.com.br/por-professor/rafael-barao.html
  • UNIX linkers produce uninitialized data segments. The segments that contain the program code and data are called text segments. These segments contain initialized data. The objects in the Block Started by Symbol segment contain only a name and size but not the value. 
    fonte:    http://www.careerride.com/Linux-what-is-BSS.aspx

  • Gabarito Errado

    O BSS representa os dados não inicializados na área de dados da memória.

     

     

     

     

    "Retroceder Nunca Render-se Jamais !"
    Força e Fé !
    Fortuna Audaces Sequitur !

  • Data segments:

    Immediately above the text segment is the data segment, which is the place where the process holds the program's global and static variables (data). Actually, it's not one mapping (segment); the data segment consists of three distinct mappings. In order from the low address, it consists of: the initialized data segment, the uninitialized data segment, and the heap segment. We understand that, in a C program, uninitialized global and static variables are automatically initialized to zero. What about initialized globals? The initialized data segment is the region of address space where explicitly initialized global and static variables are stored. The uninitialized data segment is the region of address space where, 7 course, uninitialized globals and static variables reside. The key point: these are implicitly initialized to zero (they're actually memset to zero). Also, older literature often refers to this region as the BSS. BSS is an old assembler directive - Block Started by Symbol - that can be ignored; today, the BSS region or segment is nothing but the uninitialized data segment of the process

    Fonte:

    [1] Hands-On System Programming with Linux: Explore Linux system programming, Kaiwan N Billimoria