Re: [asio-users] async_by_name() (was: deadlock when handler destructor causes close())

[Christopher K. <ch...@ko...>]

Hi Arvid,

--- Arvid Norberg <c9...@cs...> wrote:

> On Feb 18, 2006, at 19:08, Arvid Norberg wrote:
> > I don't experience any problems anymore. Nice work.
> 
> I was a little bit too quick on that conclusion.
> 
> The deadlock is gone. But instead the async_by_name (formerly known  
> as: async_get_host_by_name)

Expect even more changes when I finish adding IPv6 support ;)

> always results in an "operation aborted".
> The synchronous version works though.
> 
> This worked fine in the cvs version from about 3 weeks ago, but not  
> in today's version. (This is still MacOS X)

I see what the problem is - my fault for not testing some changes I did
thoroughly :) Sorry.

Please try the following change to
asio/ipv4/detail/host_resolver_service.hpp:

--- host_resolver_service.hpp   2 Feb 2006 07:02:03 -0000       1.19
+++ host_resolver_service.hpp   20 Feb 2006 03:48:56 -0000
@@ -71,6 +71,7 @@
   // as a cancellation token to indicate to the background thread that
the
   // operation has been cancelled.
   typedef boost::shared_ptr<void> implementation_type;
+  struct noop_deleter { void operator()(void*) {} };

   // Constructor.
   host_resolver_service(IO_Service& d)
@@ -105,6 +106,7 @@
   // Construct a new host resolver implementation.
   void construct(implementation_type& impl)
   {
+    impl.reset(static_cast<void*>(0), noop_deleter());
   }

   // Destroy a host resolver implementation.
@@ -115,7 +117,7 @@
   /// Cancel pending asynchronous operations.
   void cancel(implementation_type& impl)
   {
-    impl.reset(0);
+    impl.reset(static_cast<void*>(0), noop_deleter());
   }


Cheers,
Chris