Allocating the session before a DCB guarantees that at no point will a DCB
have a null session. This further clarifies the concept of the session and
also allows the listener reference to be moved there.
Ideally, the session itself would allocate and assign the client DCB but
since the Listener is the only one who does it, it's acceptable for now.
By storing the reference in the DCB, the two-way dependency between the
listeners and services is severed. Now the services have no direct link to
listeners and after the destruction of a listener it will be freed once
all connections through it have closed.
Due to the fact that a listener itself has a DCB that must point to a
valid listener, a self-reference is stored in the listener DCB. This is
extremely confusing and is only here to keep the code functional until the
DCB part of the listener can be factored out.
Allocating DCB with new allows the use of C++ objects in the DCB
struct. Also the explicit poll field can be replaced by inheriting from
MXB_POLL_DATA.
By storing a shared pointer to the listeners in the services, they will be
available as long as the service using them exists. This enables clean
destruction of listeners that still have open sessions.
The listener creation code now separately creates the listener and links
it to the service. Also replaced relevant parts of the related code with
the listener implemented versions of it.
The value would otherwise be assigned outside of it and in some cases not
at all. Now all DCBs (apart from internal ones) have a valid SERVICE
pointer.
The SERV_LISTENER pointer should not be in the DCBs but in the
session. This way the listener is an attribute of a session instead of a
connection. If this is implemented, the authenticator data can be more
easily shared.
The class is still mostly the same as the old C version but it now uses
std::string instead of char pointers. Changed configuration default values
so that the parameters passed to the listener allocation are always valid.
If a listener is defined in a static configuration file, it can now be
destroyed at runtime. If MaxScale is restarted, the listener will be
created again unless the configuration file is modified.
See script directory for method. The script to run in the top level
MaxScale directory is called maxscale-uncrustify.sh, which uses
another script, list-src, from the same directory (so you need to set
your PATH). The uncrustify version was 0.66.
Given that worker.hh was public, it made sense to make routingworker.hh
public as well. This removes the need to include private headers in
modules and allows C++ constructs to be used in C++ code when previously
only the C API was available.
qc_thread_init() must now explicitly be called in every thread
and not just in other threads but the one where qc_process_init()
is called.
This change was caused by QC_INIT_SELF initialization actually
being performed in query_classifier.cc. Before this change, there
actually was a leak in the routing worker running in the main
thread, the query classification cache was created twice.
The test does a request and prints the responses. It is done to see that
the functionality works. Also added a timeout of 10 seconds to both the
connection and data transfer phases.
Removed skygw_utils and relate files along with the old log manager
code. Also removed file flushing due to it being redundant; messages are
written to the file immediately. Adjusted tests to accommodate this
change.
The custom random number generator can now be replaced with a C++11
RNG. This greatly improves the reliability and trustworthiness of it.
In addition to this, the conversion of the RNG to a thread-local object
removes the race condition that was present in the previous
implementation. It also theoretically improves performance by a tiny bit.
