The Session class now contains all of the C++ objects that were previously
in the MXS_SESSION struct. It is also allocated with new but all
initialization is still done outside of the Session in session_alloc_body.
This commit will not compile as it is a part of a set of commits that make
parts of the session private.
The service now generates the configuration file that represents the
serialized form of it. Also removed the unused service_serialize_servers
function.
The services will now store a local copy of the filter lists in the worker
local data associated with the service. This removes the instance level
lock and removes the performance penalty that was previously imposed by
it.
The only remaining performance "regression" compared to 2.2 is the extra
two atomic operations per filter that a session does when it is being
created. This is quite hard to get rid of without significant amounts code
and will hopefully be just a drop in the ocean.
The most relevant string variables of a service are now duplicated as C++
strings. This should ease the eventual transition to a fully C++ internal
representation of the service. The array of refresh rates was also wrapped
inside a std::vector to remove the need to manually manage memory.
Separated the SERVICE_USER struct into its individual components as there
was no real need to have them inside a struct.
The filters can now be altered at runtime. Currently, the filter usage
uses a service level lock. The next is to allocate a per-service key to
the worker local data and use that to orchestrate the storage of the
filter lists.
Removed the explicit setters for the service parameters. Not all of them
were implemented and they were only used internally. Moved the parameter
validation and update processing inside the Service class to reduce the
load on the other parts of the core.
The service now has a private std::mutex that is used for
synchronization.
Renamed the vector of services to use snake_case.
Use lock guards with mutexes to make usage easier and safer. This makes
the code smaller as well as slightly easier to read.
The service now uses a std::vector<SFilterDef> to store the filters it
uses. Most internal parts deal with the SFilterDef but debugcmd.cc still
moves raw pointers around (needs to be changed).
The FilterDef structs are now stored in a vector<std::shared_ptr>. This
should make it easier to use filters even if they are deleted before the
session using them closes.
All internal functions now take a smart point as a parameter. One
problematic case will be debugcmd.cc which moves information around as
pointers cast into unsigned longs.
Enabling it with a value of 1 should remove the vast majority of
connection related problems that appear in MaxScale. This should filter
out most of the errors caused by transient network problems.
If the posting of a message to a message queue fails due to the queue
being full, it is retried for a limited number of times. This is a
temporary fix to the problem that fixing MXS-1948 introduced. A proper
solution that leverages SO_REUSEPORT should be implemented in the next
major release.
The service would not be in the list if it failed before it was placed
there. Moving the actual freeing of memory into the Service destructor
allows it to be called directly when we know the service is not in the
list. This also only allows valid services to be placed into the global
list of services.
To prevent freeing a partially constructed service, the memory allocation
checks were replaced with a runtime assertion. This can be changed when
the creation of the service is done only at a point where we know it can't
fail. Currently, the createInstance call expects the service as a
parameter which prevents this.
The function has use outside of the monitors as it makes execution of
worker tasks much more convenient. Currently, this change only moves the
code and takes it into use: there should be no functional changes.
Uses mostly the status functions for reading the flags. Strickly
speaking this breaks the REST API since in some cases (status combinations)
the printed string is different from what was printed before.
The signal handler no longer acquires the service list lock which removes
a number of deadlock possibilities from the shutdown process. Instead, a
global shutdown flag is set that serves the same purpose as the individual
service shutdown flags did.
The cache now enforces the defined maximum size by evicting some
entries in case the insertion of a new entry would cause the max
size to be exceeded. Currently the eviction algorithm simply
removes a random element.
Replaced the previous RESULTSET with the new implementation. As the new
ResultSet doesn't have a JSON streaming capability, the MaxInfo JSON
interface has been removed. This should not be a big problem as the REST
API offers the same information in a more secure and structured way.
