The .ti files call `DependencyGraph::AddDependency(this, service.get())`. Obviously, `service.get()` is the parent and `this` (Downtime, Notification, ...) is the child. The DependencyGraph terminology should reflect this not to confuse its future users.
Currently, for each `Disconnect()` call, we spawn a coroutine, but every
one of them is just usesless, except the first one. However, since all
`Disconnect()` usages share the same asio strand and cannot interfere
with each other, spawning another coroutine within `Disconnect()` isn't
even necessary. When a coroutine calls `Disconnect()` now, it will
immediately initiate an async shutdown of the socket, potentially causing
the coroutine to yield and allowing the others to resume. Therefore, the
`m_ShuttingDown` flag is still required by the coroutines to be checked
regularly.
Something is definitely going wrong if a client tries to reconnect to
this endpoint while it still has an active connection to that client. So
we shouldn't hide this, but at least log it at info level. Apart from
that, I've added some additional information about the currently active
client, such as when the last message was sent and received.
When the `Desconnect()` method is called, clients are not disconnected
immediately. Instead, a new coroutine is spawned using the same strand
as the other coroutines. This coroutine calls `async_shutdown` on the
TCP socket, which might be blocking. However, in order not to block
indefintely, the `Timeout` class cancels all operations on the socket
after `10` seconds. Though, the timeout does not trigger the handler
immediately; it creates spawns another coroutine using the same strand
as in the `JsonRpcConnection` class. This can cause unexpected delays if
e.g. `HandleIncomingMessages` gets resumed before the coroutine from the
timeout class. Apart from that, the coroutine for writing messages uses
the same condition, making the two symmetrical.
Especially ApiListener#ReplayLog() enqueued lots of messages into
JsonRpcConnection#{m_IoStrand,m_OutgoingMessagesQueue} (RAM) even if
the connection was shut(ting) down. Now #Disconnect() takes effect ASAP.
When a HTTP connection dies prematurely while the response is sent,
`http::async_write()` sets the error code to something like broken pipe for
example. When calling `async_flush()` afterwards, it sometimes happens that
this never returns. This results in a resource leak as the coroutine isn't
cleaned up. This commit makes the individual functions throw exceptions instead
of silently ignoring the errors, resulting in the function terminating early
and also resulting in an error being logged as well.
On incoming connection timeout we log the remote endpoint which isn't
available if it was already disconnected - an exception is thrown. Get it
as long as we're still connected not to lose it, nor to get an exception.
Closing and re-opening that very same log file shouldn't reset the
counter, otherwise some log files may exceed the max limit per file as
their offset indicator is reset each time they are re-opened.
Although there is locking involved here, it shoudln't take too long for
the thread to actually acquire it, since there aren't that many threads
dealing with endpoint clients concurrently. It's just wasting pointless
time trying to obtain a CPU slot.
If a connection hangs for too long in ApiListener#NewClientHandler(),
ApiListener#AddConnection()'s Timeout calls boost::asio::basic_socket#cancel()
on that connection to trigger an exception which unwinds
ApiListener#NewClientHandler(). Previously that unwind could trigger a Defer
which called boost::asio::ssl::stream#async_shutdown() which extended the hang.
This was accidentally broken by #9627 because during config sync, a config
validation happens that uses `--define System.ZonesStageVarDir=...` which fails
on the now frozen namespace.
This commit changes this to use `Internal.ZonesStageVarDir` instead. After all,
this is used for internal functionality, users should not directly interact
with this flag.
Additionally, it no longer freezes the `Internal` namespace which actually
allows using `Internal.ZonesStageVarDir` in the first place. This also fixes
`--define Internal.Debug*` which was also broken by said PR. Freezing of the
`Internal` namespace is not necessary for performance reasons as it's not
searched implicitly (for example when accessing `globals.x`) and should users
actually interact with it, they should know by that name that they are on their
own.
