[PATCH] Fix PR win32/24284: tcp_auto_retry doesn't work in MinGW

Pedro Alves palves@redhat.com
Thu Aug 29 12:15:00 GMT 2019

On 8/27/19 4:50 PM, Sergio Durigan Junior wrote:
> This was reported by Bernhard Wodok, along with a patch to fix the
> issue.  I adjusted the patch a bit, and I'm submitting the patch on
> his behalf.
> According to Bernhard, the issue can be reproduced by doing:
>   1. start gdb
>   2. enter 'target remote :2345'
>   3. observe that it throws a "connection refused" error immediately
>   instead of waiting and throwing a timeout error
> I.e., I believe it can be reproduced by our current tests, which is
> why I'm not proposing any extra tests here (well, I don't use nor have
> any Windows system to test this, so...).
> The problem happens because we call 'gdb_select' passing 0 as its
> first argument, 

I assume this is from wait_for_connect?  Please mention that above.

Must be, because I just now noticed that gdb_usleep is now dead code.

The comment in wait_for_connect is quite curious, kind of implies that
this worked on Windows at some point:

    /* Use gdb_select here, since we have no file descriptors, and on
       Windows, plain select doesn't work in that case.  */
    n = gdb_select (0, NULL, NULL, NULL, &t);

> --- a/gdb/mingw-hdep.c
> +++ b/gdb/mingw-hdep.c
> @@ -64,6 +64,17 @@ gdb_select (int n, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
>    int num_ready;
>    size_t indx;
> +  if (n == 0)
> +    {
> +      /* The MS API says that the first argument to
> +	 WaitForMultipleObjects cannot be zero.  That's we just use
> +	 a regular Sleep here.  */

The sentence:

 "That's we just use a regular Sleep here."

is non-grammatical.  Missing a "why" in "That's why" ?

OK with that fixed.

Pedro Alves

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