From a58ad3f801960fa0dc0bb1106eb0d99f7ebd77b1 Mon Sep 17 00:00:00 2001 From: Roland McGrath Date: Thu, 13 Jun 2013 15:09:29 -0700 Subject: Fix raciness in waitid test. --- posix/tst-waitid.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) (limited to 'posix') diff --git a/posix/tst-waitid.c b/posix/tst-waitid.c index ad3df5a329..57a6a3f769 100644 --- a/posix/tst-waitid.c +++ b/posix/tst-waitid.c @@ -145,7 +145,7 @@ do_test (int argc, char *argv[]) /* Give the child a chance to stop. */ sleep (3); - CHECK_SIGCHLD ("stopped", CLD_STOPPED, SIGSTOP); + CHECK_SIGCHLD ("stopped (before waitid)", CLD_STOPPED, SIGSTOP); /* Now try a wait that should not succeed. */ siginfo_t info; @@ -227,7 +227,7 @@ do_test (int argc, char *argv[]) expecting_sigchld = 0; } else - CHECK_SIGCHLD ("continued", CLD_CONTINUED, SIGCONT); + CHECK_SIGCHLD ("continued (before waitid)", CLD_CONTINUED, SIGCONT); info.si_signo = 0; /* A successful call sets it to SIGCHLD. */ info.si_pid = -1; @@ -336,6 +336,13 @@ do_test (int argc, char *argv[]) printf ("kill (%d, SIGSTOP): %m\n", pid); RETURN (EXIT_FAILURE); } + + /* Give the child a chance to stop. The waitpid call below will block + until it has stopped, but if we are real quick and enter the waitpid + system call before the SIGCHLD has been generated, then it will be + discarded and never delivered. */ + sleep (3); + pid_t wpid = waitpid (pid, &fail, WUNTRACED); if (wpid < 0) { @@ -354,7 +361,7 @@ do_test (int argc, char *argv[]) printf ("waitpid WUNTRACED on stopped: status %x\n", fail); RETURN (EXIT_FAILURE); } - CHECK_SIGCHLD ("stopped", CLD_STOPPED, SIGSTOP); + CHECK_SIGCHLD ("stopped (after waitpid)", CLD_STOPPED, SIGSTOP); expecting_sigchld = 1; if (kill (pid, SIGCONT) != 0) @@ -372,7 +379,7 @@ do_test (int argc, char *argv[]) expecting_sigchld = 0; } else - CHECK_SIGCHLD ("continued", CLD_CONTINUED, SIGCONT); + CHECK_SIGCHLD ("continued (before waitpid)", CLD_CONTINUED, SIGCONT); wpid = waitpid (pid, &fail, WCONTINUED); if (wpid < 0) -- cgit v1.2.1