[Libguestfs] [PATCH nbdkit 1/3] server: Add GET_CONN macro, alias for threadlocal_get_conn ().

[Richard W.M. Jones]

On Tue, Feb 11, 2020 at 11:25:49AM -0600, Eric Blake wrote:
> On 2/11/20 11:15 AM, Richard W.M. Jones wrote:
> >Since we're going to be calling this function a lot, add a short alias
> >for it.
> >---
> >  server/internal.h | 1 +
> >  server/public.c   | 6 +++---
> >  2 files changed, 4 insertions(+), 3 deletions(-)
> >
> >diff --git a/server/internal.h b/server/internal.h
> >index a1fa7309..1e7b4cf0 100644
> >--- a/server/internal.h
> >+++ b/server/internal.h
> >@@ -493,6 +493,7 @@ extern int threadlocal_get_error (void);
> >  extern void *threadlocal_buffer (size_t size);
> >  extern void threadlocal_set_conn (struct connection *conn);
> >  extern struct connection *threadlocal_get_conn (void);
> >+#define GET_CONN (threadlocal_get_conn ())
> 
> Do we want any checking, such as whether this is non-NULL?
> 
> For example, patch 3 has:
> 
> -typedef void (*connection_close_function) (struct connection *)
>    __attribute__((__nonnull__ (1)));
> +typedef void (*connection_close_function) (void);
> 
> which loses the compile-time checking that we have a non-NULL
> connection parameter; so replacing a parameter passed through a
> nonnull attribute with a macro that guarantees a nonnull result
> might be in our favor, where we can leave explicit calls to
> threadlocal_get_conn() rather than macro usage for the few callers
> that expect to handle the corner cases where a threadlocal
> connection might not yet be set.

Yes let's do this.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
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