This commit moves the initialization of the globals.Types namespace to type.cpp
in order to keep a pointer to the Namespace object in Type::m_Namespace and
simplify Type::GetByName() using it.
The dynamic type check is moved into an assertion after freezing the namespace.
This makes freezing a namespace an irrevocable operation but in return allows
omitting further lock operations. This results in a performance improvement as
reading an atomic bool is faster than acquiring and releasing a shared lock.
ObjectLocks on namespaces remain untouched as these mostly affect write
operations which there should be none of after freezing (if there are some,
they will throw exceptions anyways).
This commit removes EmbeddedNamespaceValue and ConstEmbeddedNamespaceValue and
reduces NamespaceValue down to a simple struct without inheritance or member
functions. The code from these clases is inlined into the Namespace class. The
class hierarchy determining whether a value is const is moved to an attribute
of NamespaceValue.
This is done in preparation for changes to the locking in the Namespace class.
Currently, it relies on a recursive mutex. In the future, a shared mutex
(read/write lock) should be used instead, which cannot allow recursive locking
(without failing or risk deadlocking on lock upgrades). With this change, all
operations requiring a lock for one operation are within one function, no
recursive locking is not needed any more.
This commit adds a new initialization priority `FreezeNamespaces` that is run
last and moves all calls to `Namespace::Freeze()` there. This allows all other
initialization functions to still update namespaces without the use of the
`overrideFrozen` flag.
It also moves the initialization of `System.Platform*` and `System.Build*` to
an initialize function so that these can also be set without setting
`overrideFrozen`.
This is preparation for a following commit that will make the frozen flag in
namespaces finial, no longer allowing it to be overriden (freezing the
namespace will disable locking, so performing further updates would be unsafe).
Now that all values are in one place, there is no reason for this numbering
with gaps anymore. If you need to insert a new value in between, you can just
do so in the enum.
This reverses the sort order of the enum, thereby requiring a change to the
sort order of the std::priority_queue containing the elements.
Change the type of the priority values from int to a new enum. By replacing the
magic int values throughout the code base with named values, there is now a
single place where all priority values are defined and you get an overview over
the initialization order.
InitializeOnceHelper calls Loader::AddDeferredInitializer which takes a
std::function, so it's eventually converted to that anyways. This commit just
does this a bit earlier, and by saving the step of the intermediate C function
pointer, this would now also work for capturing lambdas (which there are none
of at the moment).
In essence, namespace behaviors acted as hooks for update operations on
namespaces. Two behaviors were implemented:
- `NamespaceBehavior`: allows the update operation unless it acts on a value
that itself was explicitly marked as constant.
- `ConstNamespaceBehavior`: initially allows insert operations but marks the
individual values as const. Additionally provides a `Freeze()` member
function. After this was called, updates are rejected unless a special
`overrideFrozen` flag is set explicitly.
This marvel of object-oriented programming can be replaced with a simple bool.
This commit basically replaces `Namespace::m_Behavior` with
`Namespace::m_ConstValues` and inlines the behavior functions where they were
called. While doing so, the code was slightly simplified by assuming that
`m_ConstValues` is true if `m_Frozen` is true. This is similar to what the API
allowed in the old code as you could only freeze a `ConstNamespaceBehavior`.
However, this PR moves the `Freeze()` member function and the related
`m_Freeze` member variable to the `Namespace` class. So now the API allows any
namespace to be frozen. The new code also makes sense with the previously
mentioned simplification: a `Namespace` with `m_ConstValues = false` can be
modified without restrictions until `Freeze()` is called. When this is done, it
becomes read-only.
The changes outside of `namespace.*` just adapt the code to the slightly
changed API.
Copying an ObjectLock results in the underlying mutex being unlocked too often.
There's also no good reason for copying a scoped locking class (if at all, it
should be moved).
by caching the total minimum log severity of all loggers in a
"global variable" and whether a message's severity is large enough for any of
the loggers in a per-message no-op flag.
The point of logging to the Windows Event Log was to catch errors that happen
before the full logging configuration has been loaded and enabled. Messages
like the number of loaded objects per type just cause noise in the log and
provide little benefit. Therefore raise the required log level at this stage.
Note that this commit removes the (never documented) ability to use the -x flag
to change the level. But doing so would require patching the command line of
the service in the registry anyways.
Apparently there was a reason for making the members of generated classes
atomic. However, this was only done for some types, others were still accessed
using non-atomic operations. For members of type T::Ptr (i.e. intrusive_ptr<T>),
this can result in a double free when multiple threads access the same variable
and at least one of them writes to the variable.
This commit makes use of std::atomic<T> for more T (it removes the additional
constraint sizeof(T) <= sizeof(void*)) and uses a type including a mutex for
load and store operations as a fallback.
Julian Brost
Alexander Aleksandrovič Klimov
Yonas Habteab