Re: CVS commit: src/tests/kernel

[Paul Goyette <paul%whooppee.com@localhost>]

On Tue, 19 Feb 2013, Joerg Sonnenberger wrote:

> > Wait a little bit after fork()ing the lockers to give them a chance to
> > get started before trying to ptrace(ATTACH).
>
> What about using a pipe to make this an explicit barrier?


You mean something like this?    :)


Index: t_lockf.c
===================================================================
RCS file: /cvsroot/src/tests/kernel/t_lockf.c,v
retrieving revision 1.3
diff -u -p -r1.3 t_lockf.c
--- t_lockf.c   19 Feb 2013 00:54:47 -0000      1.3
+++ t_lockf.c   19 Feb 2013 03:24:01 -0000
@@ -118,8 +118,10 @@ ATF_TC_HEAD(randlock, tc)
 ATF_TC_BODY(randlock, tc)
 {
        int i, j, fd;
+       int pipe_fd[2];
        pid_t *pid;
        int status;
+       char pipe_in, pipe_out;

        (void)unlink(lockfile);

@@ -132,19 +134,30 @@ ATF_TC_BODY(randlock, tc)
        fsync(fd);
        close(fd);

+       ATF_REQUIRE_MSG(pipe(pipe_fd) == 0, "pipe: %s", strerror(errno));
+
        pid = malloc(nprocs * sizeof(pid_t));

        for (i=0; i<nprocs; i++) {
+               pipe_out = (char)('A' + i);
                pid[i] = fork();
                switch (pid[i]) {
                case 0:
-                       trylocks(i);
+                       if (write(pipe_fd[1], &pipe_out, 1) != 1)
+                               printf("write_pipe(%i): %s", i,
+                                   strerror(errno));
+                       else
+                               trylocks(i);
                        _exit(0);
                        break;
                case -1:
                        atf_tc_fail("fork %d failed", i);
                        break;
                default:
+                       ATF_REQUIRE_MSG(read(pipe_fd[0], &pipe_in, 1) == 1,
+                           "parent: read_pipe(%i): %s", i, strerror(errno));
+                       ATF_REQUIRE_MSG(pipe_in == pipe_out,
+                           "parent: pipe does not match");
                        break;
                }
        }



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