The stop sequence for Overlay had a race condition where autoconnect could
be called after close_all, resulting in a hang on exit. This resolves the
problem by putting the close and timer operations on a strand:
* Rename some Overlay members
* Put close on strand and tidy up members
* Use completion handler instead of coroutine for timer
* Use App io_service in PeerFinder
These changes prepare Overlay for the Universal Port and Hub and Spoke
features.
* Add [overlay configuration section:
The [overlay] section uses the new BasicConfig interface that
supports key-value pairs in the section. Some exposition is added to the
example cfg file. The new settings for overlay are related to the Hub and
Spoke feature which is currently in development. Production servers should
not set these configuration options, they are clearly marked experimental
in the example cfg file.
Other changes:
* Use _MSC_VER to detect Visual Studio
* Use ssl_bundle in Overlay::Peer
* Use shared_ptr to SSL context in Overlay:
* Removed undocumented PEER_SSL_CIPHER_LIST configuration setting
* Add Section::name: The Section object now stores its name for better diagnostic messages.
This changes the http::message object to no longer contain a body. It modifies
the parser to store the body in a separate object, or to pass the body data
to a functor. This allows the body to be stored in more flexible ways. For
example, in HTTP responses the body can be generated procedurally instead
of being required to exist entirely in memory at once.
On Application exit, Overlay was calling PeerImp::close for each peer.
The implementation of PeerImp::close only canceled all pending I/O and did not
call functions necessary for proper transition of Peer state during socket
closure. The correct transition is ensured by calling PeerImp::detach. This
changes PeerImp::close to call PeerImp::detach instead, ensuring that Overlay
invariants are maintained. Specifically, that reference counts for pending I/O
on peers will be correctly unwound by canceling operations and that the Peer
object will be destroyed, thus allowing the Overlay to stop correctly.
The MultiSocket is obsolete technology which is superceded by a more
straightforward, template based implementation that is compatible with
boost::asio::coroutines. This removes support for the unused PROXY handshake
feature. After this change a large number of classes and source files may be
removed.
This changes the HTTP parser interface to return an error_code instead
of a bool. This eliminates the need for the error() member function and
simplifies calling code.
If we receive a deferred transaction from a server in our
cluster, treat it as if it wasn't received from a server
in our cluster.
This currently has no effect but is needed for server to
interoperate with future code that will relay deferred
transactions.
Previously, the PeerFinder manager constructed with a Callback object
provided by the owner which was used to perform operations like connecting,
disconnecting, and sending messages. This made it difficult to change the
overlay code because a single call into the PeerFinder could cause both
OverlayImpl and PeerImp to be re-entered one or more times, sometimes while
holding a recursive mutex. This change eliminates the callback by changing
PeerFinder functions to return values indicating the action the caller should
take.
As a result of this change the PeerFinder no longer needs its own dedicated
thread. OverlayImpl is changed to call into PeerFinder on a timer to perform
periodic activities. Furthermore the Checker class used to perform connectivity
checks has been refactored. It no longer uses an abstract base class, in order
to not type-erase the handler passed to async_connect (ensuring compatibility
with coroutines). To allow unit tests that don't need a network, the Logic
class is now templated on the Checker type. Currently the Manager provides its
own io_service. However, this can easily be changed so that the io_service is
provided upon construction.
Summary
* Remove unused SiteFiles dependency injection
* Remove Callback and update signatures for public APIs
* Remove obsolete functions
* Move timer to overlay
* Steps toward a shared io_service
* Templated, simplified Checker
* Tidy up Checker declaration
* New I/O paths for client and server role
* New handshake_analyzer detects the peer protocol
* New basic_message class for parsing and storing HTTP messages
* Conditional compilation for selective feature enabling.
* Server supports both current handshake and HTTP handshake
