Instead of using one file for the entire "backend" of the ProcFS data
and metadata, we could split that file into two files that represent
2 logical chunks of the ProcFS exposed objects:
1. Global and inter-process information. This includes all fixed data in
the root folder of the ProcFS, networking information and the bus
folder.
2. Per-process information. This includes all dynamic data about a
process that resides in the /proc/PID/ folder.
This change makes it more easier to read the code and to change it,
hence we do it although there's no technical benefit from it now :)
The new ProcFS design consists of two main parts:
1. The representative ProcFS class, which is derived from the FS class.
The ProcFS and its inodes are much more lean - merely 3 classes to
represent the common type of inodes - regular files, symbolic links and
directories. They're backed by a ProcFSExposedComponent object, which
is responsible for the functional operation behind the scenes.
2. The backend of the ProcFS - the ProcFSComponentsRegistrar class
and all derived classes from the ProcFSExposedComponent class. These
together form the entire backend and handle all the functions you can
expect from the ProcFS.
The ProcFSExposedComponent derived classes split to 3 types in the
manner of lifetime in the kernel:
1. Persistent objects - this category includes all basic objects, like
the root folder, /proc/bus folder, main blob files in the root folders,
etc. These objects are persistent and cannot die ever.
2. Semi-persistent objects - this category includes all PID folders,
and subdirectories to the PID folders. It also includes exposed objects
like the unveil JSON'ed blob. These object are persistent as long as the
the responsible process they represent is still alive.
3. Dynamic objects - this category includes files in the subdirectories
of a PID folder, like /proc/PID/fd/* or /proc/PID/stacks/*. Essentially,
these objects are always created dynamically and when no longer in need
after being used, they're deallocated.
Nevertheless, the new allocated backend objects and inodes try to use
the same InodeIndex if possible - this might change only when a thread
dies and a new thread is born with a new thread stack, or when a file
descriptor is closed and a new one within the same file descriptor
number is opened. This is needed to actually be able to do something
useful with these objects.
The new design assures that many ProcFS instances can be used at once,
with one backend for usage for all instances.
The intention is to add dynamic mechanism for notifying the userspace
about hotplug events. Currently, the DMI (SMBIOS) blobs and ACPI tables
are exposed in the new filesystem.
This does the exact thing as `adopt_ref`, which is a recent addition to
AK.
Note that pointers returned by a bare new (without `nothrow`) are
guaranteed not to return null, so they can safely be converted into
references.
This optimization has already been done in LibC's `assert.h`, which
Userland `VERIFY()` calls resolve to. We now use it in the kernel, but
with the nicer C++ *unlikely* attribute instead of `__builtin_expect`.
This tells the compiler to arrange the generated machine code so that
the error-free branches execute faster (e.g. fewer jumps, better cache
locality).
This attribute tells compilers that the pointer returned by a function
is never null, which lets it optimize away null checks in some places.
This seems like a nice addition to `NonnullOwnPtr` and `NonnullRefPtr`.
Using this attribute causes extra UBSan checks to be emitted. To offset
its performance loss, some additional methods were marked ALWAYS_INLINE,
which lets the compiler optimize duplicate checks
This will cause a problem when `NonnullRefPtr<T>::operator T*` will be
declared as RETURNS_NONNULL. Clang emits a warning for this pointless
null check, which breaks CI.
Because of the added complexity of *non-throwing* `new`, helper methods
for correctly constructing smart pointers were added in a previous
commit. This commit changes the documentation to recommend using these,
and adds examples to aid in correctly determining when to use
non-throwing new when manually creating smart pointers.
This is not exactly compliant with the specification, but our current
bound function implementation isn't either, so its not currently
possible to implement it the way the specification requires.
Docker is a nice way of doing build automation, or just
containerizing builds for increased safety and isolating unstable
packages. The old Dockerfile in the toolchain did not satisfy these
needs. The new Dockerfile is known to run successfully on Docker
version 20.10.7. It clones the SerenityOS repo and builds the
toolchain. In this way, it is intended to be a starting point for other
Docker images that can e.g. run builds. For example, one can simply run
this docker image as-is, exec a shell in it and run a build there.
This removes JsonObject::get_or(), which is inefficient because it has
to copy the returned value. It was only used in a few cases, some of
which resulted in copying JsonObjects, which can become quite large.
This adds methods to JsonObject to check if a key exists with a certain
type. This simplifies code that validates whether a JsonObject has the
expected structure.
This adds a static JsonValue* s_null_value, which allows
JsonObject::get to return a reference instaed of copying the return
value. Since JsonValue is only 16 bytes, this seems like a reasonable
compromise.
This changes JsonObject to use the new OrderedHashMap instead of an
extra vector for tracking the insertion order.
This also adds a default value for the KeyTraits template argument in
OrderedHashMap. Furthermore, it fixes two cases where code iterating
over a JsonObject relied on the value argument being copied before
invoking the callback.
If there are no search results in the list, we shouldn't do anything
when you try to active the selected result, since there isn't one.
Fix this by using an Optional<size_t> to store the selected index.
If something happens in response to on_change that causes the widget
to get unparented, creating a GUI::Painter will fail since it can't
find the window to paint into.
Since painting only cares about the syntax highlighting spans, what we
really want is to ensure that spans are up-to-date before we start
painting.
The problem was that rehighlighting and the on_change hook were bundled
together in an awkward lazy update mechanism. This patch fixes that by
decoupling rehighlighting and on_change. Rehighlighting is now lazy
and only happens when we handle either paint or mouse events. :^)
Fixes#8302.
This was causing CrashDaemon to choke on our coredumps. Note that we
didn't care about the validation failures before this change either,
this patch simply reorders the checks to avoid divide-by-zero when
validating an ET_CORE file.
