It doesn't seem sane to try to iterate over a HashTable while it's in
the middle of being cleared. Since this might cause strange problems,
this patch adds an assertion if an iterator is constructed during
clear() or rehash() of a HashTable.
An operation often has two pieces of underlying information:
* the data returned as a result from that operation
* an error that occurred while retrieving that data
Merely returning the data is not good enough. Result<> allows exposing
both the data, and the underlying error, and forces (via clang's
consumable attribute) you to check for the error before you try to
access the data.
Put simply, Error<> is a way of forcing error handling onto an API user.
Given a function like:
bool might_work();
The following code might have been written previously:
might_work(); // but what if it didn't?
The easy way to work around this is of course to [[nodiscard]] might_work.
But this doesn't work for more complex cases like, for instance, a
hypothetical read() function which might return one of _many_ errors
(typically signalled with an int, let's say).
int might_read();
In such a case, the result is often _read_, but not properly handled. Like:
return buffer.substr(0, might_read()); // but what if might_read returned an error?
This is where Error<> comes in:
typedef Error<int, 0> ReadError;
ReadError might_read();
auto res = might_read();
if (might_read.failed()) {
switch (res.value()) {
case EBADF:
...
}
}
Error<> uses clang's consumable attributes to force failed() to be
checked on an Error instance. If it's not checked, then you get smacked.
We had some kernel-specific gizmos in AK that should really just be in the
Kernel subdirectory instead. The only thing remaining after moving those
was mmx_memcpy() which I moved to the ARCH(i386)-specific section of
LibC/string.cpp.
So we already have ByteBuffer::wrap() which is like a StringView for random
data. This might not be the best abstraction actually, but this will be
immediately useful so let's add it.
Clang loses the typestate when passing NonnullRefPtr's via lambda captures.
This is unfortunate, but not much we can do about it. Allowing ptr() makes
it possible to use captured NonnullRefPtrs as you'd expect.
Add an "ElementType" typedef to NonnullOwnPtr and NonnullRefPtr to allow
clients to easily find the pointee type. Then use this to remove a template
argument from NonnullPtrVector. :^)
It's not possible to grow one of these vectors beyond what's already in them
since it's not possible to default-construct Nonnull{Own,Ref}Ptr.
Add Vector::shrink() which can be used when you want to shrink the Vector
and delete resize() from the specialized Vectors.
This works just like NonnullRefPtr, except for NonnullOwnPtr's instead.
NonnullOwnPtrVector<T> inherits from Vector<NonnullOwnPtr<T>>, and adds some
comforts on top, like making accessors return T& so we can chase dots (.)
instead of arrows (->) :^)
This is just like OwnPtr (also single-owner), except it cannot be null.
NonnullOwnPtr is perfect as the return type of functions that never need to
return nullptr.
It's also useful as an argument type to encode the fact that the argument
must not be nullptr.
The make<Foo>() helper is changed to return NonnullOwnPtr<Foo>.
Note: You can move() out of a NonnullOwnPtr, and after that the object is
in an invalid state. Internally it will be a nullptr at this point, so we'll
still catch misuse, but the only thing that should be done in this state
is running the destructor. I've used consumable annotations to generate some
warnings when using a NonnullOwnPtr after moving from it, but these only
work when compiling with clang, so be aware of that.
Restructure the makefile a little so it only builds objects once, and
then run them on make clean.
This is a little slower (since we're relinking tests each makeall), but
it also ensures that it will work.
And use it in the scheduler.
IntrusiveList is similar to InlineLinkedList, except that rather than
making assertions about the type (and requiring inheritance), it
provides an IntrusiveListNode type that can be used to put an instance
into many different lists at once.
As a proof of concept, port the scheduler over to use it. The only
downside here is that the "list" global needs to know the position of
the IntrusiveListNode member, so we have to position things a little
awkwardly to make that happen. We also move the runnable lists to
Thread, to avoid having to publicize the node.
The to_foo() functions are for converting when you might not be sure of the
underlying value type. The as_foo() family assumes that you know exactly
what the underlying value type is.
Meet TStyle. It allows you to write things like this:
dbg() << TStyle(TStyle::Red, TStyle::Bold) << "Hello, friends!";
Any style used will be reset along with the newline emitted when the dbg()
temporary goes out of scope. :^)
This can definitely be improved, but I think it's a decent place to start.
This is the same as calling FileSystemPath(foo).string(). The majority of
clients only care about canonicalizing a path, so let's have an easy way
to express that.
We shouldn't allow constructing e.g an OwnPtr from a RefPtr, and similar
conversions. Instead just delete those functions so the compiler whines
loudly if you try to use them.
This patch also deletes constructing OwnPtr from a WeakPtr, even though
that *may* be a valid thing to do, it's sufficiently weird that we can
make the client jump through some hoops if he really wants it. :^)
This patch removes copy_ref() from RefPtr and NonnullRefPtr. This means that
it's now okay to simply copy these smart pointers instead:
- RefPtr = RefPtr // Okay!
- RefPtr = NonnullRefPtr // Okay!
- NonnullRefPtr = NonnullRefPtr // Okay!
- NonnullRefPtr = RefPtr // Not okay, since RefPtr can be null.
I had a silly ambition that we would avoid unnecessary ref count churn by
forcing explicit use of "copy_ref()" wherever a copy was actually needed.
This was making RefPtr a bit clunky to work with, for no real benefit.
This patch adds the missing copy construction/assignment stuff to RefPtr.
You can currently use this to detect the CPU architecture like so:
#if ARCH(I386)
...
#elif ARCH(X86_64)
...
#else
...
#endif
This will be helpful for separating out architecture-specific code blocks.
Instead of computing the path length inside the syscall handler, let the
caller do that work. This allows us to implement to new variants of open()
and creat(), called open_with_path_length() and creat_with_path_length().
These are suitable for use with e.g StringView.
This makes me wonder if the open() syscall should take characters+length
and we'd compute the length at the LibC layer instead. That way we could
also provide an optional non-POSIX open() that takes the length directly..
This allows you to do things like:
vector.insert_before_matching(value, [](auto& entry) {
return value < entry;
});
Basically it scans until it finds an element that matches the condition
callback and then inserts the new value before the matching element.
The first implementation class is DebugLogStream, which can be used like so:
dbg() << "Hello friends, I am " << m_years << " years old!";
Note that it will automatically print a newline when the object created by
dbg() goes out of scope.
This API will grow and evolve, so let's see what we end up with :^)
Instead of manually doing String::format("%d"/"%u") everywhere, let's have
a String API for this. It's just a wrapper around format() for now, but it
could be made more efficient in the future.
Solve this by adding find() overloads to HashTable and SinglyLinkedList
that take a templated functor for comparing the values.
This allows HashMap to call HashTable::find() without having to create
a temporary Entry for use as the table key. :^)
This is prep work for supporting HashMap with NonnullRefPtr<T> as values.
It's currently not possible because many HashTable functions require being
able to default-construct the value type.
Update ProcessManager, top and WSCPUMonitor to handle the new format.
Since the kernel is not allowed to use floating-point math, we now compile
the JSON classes in AK without JsonValue::Type::Double support.
To accomodate large unsigned ints, I added a JsonValue::Type::UnsignedInt.
The LibC build is a bit complicated, since the toolchain depends on it.
During the toolchain bootstrap, after we've built parts of GCC, we have
to stop and build Serenity's LibC, so that the rest of GCC can use it.
This means that during that specific LibC build, we don't yet have access
to things like std::initializer_list.
For now we solve this by defining SERENITY_LIBC_BUILD during the LibC
build and excluding the Vector/initializer_list support inside LibC.
Get rid of the ConstIterator classes for these containers and use templated
FooIterator<T, ...> and FooIterator<const T, ...> helpers.
This makes the HashTable class a lot easier to read.
This means you can now do this:
void harmonize(NonnullRefPtrVector<Voice>& voices)
{
for (auto& voice : voices) {
voice.sing(); // Look, no "->"!
}
}
Pretty dang cool :^)
This is a slot-in convenience replacement for Vector<NonnullRefPtr<T>> that
makes accessors return T& instead of NonnullRefPtr<T>&.
Since NonnullRefPtr guarantees non-nullness, this allows you to access these
vector elements using dot (.) rather than arrow (->). :^)
