Home • About Us • A-Z Index • Search * Contact Us • Register • Login • Press • Shop

The Open Brand -- Problem Reporting and Interpretations System

Problem Report 1442 Details

Help Show help | Quick Search | Submit a Test Suite Support Request | Click here to view your privileges

This page provides all information on Problem Report 1442.

Report 1442 Actions

    Problem Report Number 1442
    Submitter's Classification Test Suite problem
    State Resolved
    Resolution Test Suite Deficiency (TSD)
    Problem Resolution ID TSD.X.0724
    Raised 1970-01-01 08:00
    Updated 2003-03-13 08:00
    Published 1995-12-15 08:00
    Product Standard Internationalised System Calls and Libraries Extended (UNIX 95)
    Certification Program The Open Brand certification program
    Test Suite VSU version 4.0.2
    Test Identification CAPIbase/sigaction 30
    Problem Summary TSD4U.00091 The test may fail on implementations because the signal handler in a race condition may catch the child process exiting.
    Problem Text
    The test may fail on implementations because the signal handler in a
    race condition may catch the child process exiting.

    The purpose of the sigaction 30 test (test30A()) is to verify that
    a SIGCHLD signal and associated siginfo data is received by the
    parent process when a child process which is stopped as a result
    of job control is continued via the SIGCONT signal.

    The sigaction 30 test fails due to an error in the test program.
    Specifically, the test needs to reset or disable the SIGCHLD signal
    handler after the second SIGCHLD signal is sent. A SIGCHLD signal will
    be posted to the parent test process 3 times during the test -- once
    when the child process is stopped, once when the child process is
    continued and once when the child process exits. Each time the SIGCHLD
    signal is posted, different data will be passed to the signal handler
    via the siginfo structure. Since the test program does not reset the
    signal handler for SIGCHLD after the second SIGCHLD signal is received
    (on process continue), the third SIGCHLD signal (on process exit) causes
    the same signal handler (sh_30A()) to incorrectly be invoked again. The
    signal handler incorrectly checks for a siginfo si_code value of
    CLD_CONTINUED and gets an si_code value of CLD_EXITED. The test program
    should either disable or reset the SIGCHLD signal handler after the
    second SIGCHLD signal is received (on process continue).

    The incorrect behavior of the test program is evident from the test
    output (see my comments following the '#' character):

    PREP: Set up action for SIGCHLD # set up handler for proc stop
    PREP: fork() a child that stops itself
    PREP: Set up action for SIGCHLD # set handler to sh_30A() for proc continue
    TEST: Send SIGCONT to child
    TEST: signal = SIGCHLD # parent gets SIGCLD after SIGCONT sent
    TEST: si_code = CLD_CONTINUED # si_code correctly set to CLD_CONTINUED
    TEST: si_status = SIGCONT # si_status correctly set to SIGCONT
    TEST: signal = SIGCHLD # parent gets 3rd SIGCLD after child exits
    TEST: si_code = CLD_CONTINUED # sh_30A handler still installed and
    # incorrectly tests for CLD_CONTINUED again...
    ERROR: si_code incorrect. Expected 6,Received 1 # and finds CLD_EXITED
    TEST: si_status = SIGCONT # should be testing for exit value here
    ERROR: si_status incorrect. Expected SIGCONT,Received Unknown signal (0)

    To fix the test in a manner that will prevent race conditions in the
    test program, the signal handler should be disabled or reset from within
    the signal handler (sh_30A()).
    Test Output
    TEST PURPOSE #30
    After a call to int sigaction(int sig, const struct
    sigaction *act, struct sigaction *oact) with
    SA_SIGINFO set in the sa_flags member of the sigaction
    structure pointed to by act and sig equal to SIGCHLD,
    on entry to the signal catching function specified by
    the sa_handler member when the stopped child has
    continued the si_code member of the structure pointed
    to by the siginfo argument shall contain
    CLD_CONTINUED, the si_pid member shall contain the
    child process ID, the si_status member shall contain
    the child's signal and the si_uid member
    shall contain the real user ID of the process that
    sent the signal.
    PREP: Set up action for SIGCHLD
    PREP: fork() a child that stops itself
    PREP: Set up action for SIGCHLD
    TEST: Send SIGCONT to child
    TEST: signal = SIGCHLD
    TEST: si_code = CLD_CONTINUED
    TEST: si_status = SIGCONT
    TEST: signal = SIGCHLD
    TEST: si_code = CLD_CONTINUED
    ERROR: si_code incorrect. Expected 6,Received 1
    TEST: si_status = SIGCONT
    ERROR: si_status incorrect. Expected SIGCONT,Received Unknown signal (0)

    30 FAIL

    Review Information

    Review Type TSMA Review
    Start Date null
    Completed null
    Status Complete
    Review Recommendation No Resolution Given
    Review Response
    We agree this is a test suite deficiency in the test
    suite version(s) listed.

    Review Type SA Review
    Start Date null
    Completed null
    Status Complete
    Review Resolution Test Suite Deficiency (TSD)
    Review Conclusion
    This is an agreed Test Suite Deficiency.

    Problem Reporting System Options:

     

    Back   

Contact the Certification Authority