Re: Program-assigned thread names on Windows

[John Baldwin <jhb@freebsd.org>]

On Saturday, July 23, 2016 12:25:15 PM LRN wrote:
> The attached patch adds thread naming support on Windows.
> 
> This works as documented[1] on MSDN - by catching a specific
> exception that the program throws.
> 
> Setting thread name this way is supported by glib[2] and winpthreads[3] at
> least, as well as any program developed with MS toolchain (because WinDbg
> supported this for a long time).
> 
> [1] https://msdn.microsoft.com/en-us/library/xcb2z8hs.aspx
> [2]
> https://git.gnome.org/browse/glib/commit/glib/gthread-win32.c?id=e118856430a798bbc529691ad235fd0b0684439d
> [3]
> https://sourceforge.net/p/mingw-w64/mingw-w64/ci/0d95c795b44b76e1b60dfc119fd93cfd0cb35816/

Does this leak 'thread_name' if the first character is '\0'?

+         thread_name = NULL;
+         if (!target_read_string ((CORE_ADDR) thread_name_target, &thread_name, 1024, 0)
+             || !thread_name || !*thread_name)
+           /* nothing to do */;
+         else
+           {
+             xfree (named_thread->name);
+             named_thread->name = thread_name;
+           }
+         result = 2;

Maybe restructure as:

    if (target_read_string (...))
      {
        if (thread_name && thread_name[0] != '\0')
          {
            xfree (named_thread->name);
            named_thread->name = thread_name;
          }
        else
          xfree (thread_name);
      }

-- 
John Baldwin