Re: BUG #6166: configure from source fails with 'This platform is not thread-safe.' but was actually /tmp perms

Bruce Momjian <bruce@momjian.us> writes:
> Tom Lane wrote:
>> (The error message seems to be suffering from a bad case of copy-and-
>> paste-itis, too.)

> Actually, it is accurate.  The code is:

>     #ifdef WIN32
>         h1 = CreateFile(TEMP_FILENAME_1, GENERIC_WRITE, 0, NULL, OPEN_ALWAYS, 0, NULL);
>         h2 = CreateFile(TEMP_FILENAME_1, GENERIC_WRITE, 0, NULL, CREATE_NEW, 0, NULL);
>         if (h1 == INVALID_HANDLE_VALUE || GetLastError() != ERROR_FILE_EXISTS)
>     #else
>         if (open(TEMP_FILENAME_1, O_RDWR | O_CREAT, 0600) < 0 ||
>             open(TEMP_FILENAME_1, O_RDWR | O_CREAT | O_EXCL, 0600) >= 0)
>     #endif
>         {
>             fprintf(stderr, "Could not create file in current directory or\n");
>             fprintf(stderr, "could not generate failure for create file in current directory **\nexiting\n");
>             exit(1);
>         }

> This code generates an errno == EEXIST in one thread, while another
> thread generates errno == ENOENT, and this is how we test for errno
> being thread-safe.  If you have a cleaner way to do this, please let me
> know.  mkdir()?

The problem with that is you're trying to make one error message serve
for two extremely different failure conditions.  I think this should be
coded more like

        if (open(TEMP_FILENAME_1, O_RDWR | O_CREAT, 0600) < 0)
        {
        report suitable failure message;
        exit(1);
        }
        if (open(TEMP_FILENAME_1, O_RDWR | O_CREAT | O_EXCL, 0600) >= 0)
        {
        report suitable failure message;
        exit(1);
        }

You would probably find that the messages could be a lot more clear and
specific if they were done like that.  Also, a file-related error
message that doesn't provide the filename nor strerror(errno) is pretty
much wrong on its face, in my book.

            regards, tom lane