The asio stuff is quite broken when it comes to, ironically,
concurrency.
Connecting to peers lead to lots of 'canceled' (sic) errors being
generated internally in asio and other such issues.
Even though they were called on separate objects.
Adding a mutex around the async_connect calls made the amount of
failures go down dramatically.
This patch also includes upgrading boost::mutex to the std-lib
versions.
Avoid deleting and creating connections, which is really a rather rare
event anyway, and simply remember the connection object and reuse it
when a new one is requested.
The NetworkManager usage was mostly for low connection counts and this
made defaults selection easy.
With more usages it is important to allow the NWM-connection to be more
configurable about memory usage and leaner in general.
This changes the headers-buffers (used to create envelopes) to not be per
connection anymore but per thread using the tread_local keyword.
This changes the ring-buffers to become configurable using
NetworkConnections::setMessageQueueSizes().
Also removing some include statements where they were not really needed
in the P2PNet lib.
This changes handling to also remove peers that fail with:
"Cannot assign requested address"
An error seen in a Docker container on a system supporting IPv6.
Additionally we now always assign a error level so an unknown error will
still cause the node to be banned after 5 attempts.
This avoids a race condition on remove/delete of peer where
the connection manager decides to delete a peer while in its own thread
the peer is processing a package.
This moves deletion of the peer to its own strand.
We reuse the NetworkManager lower level code in order to connect
to the Bitcoin P2P network.
This implements the basics for anyone wanting to be a player on
this network.
TomZ