The way we use classes like Kernel::KResultOr<T> and AK::Result<T, E>
makes checking for errors (and short-circuiting returns) quite verbose.
This patch adds a new TRY(expression) macro that either evaluates to
the released result of the expression if successful, or returns the
error if not.
Before:
auto foo_or_error = get_foo();
if (foo_or_error.is_error())
return foo_or_error.release_error();
auto foo = foo_or_error.release_value();
After:
auto foo = TRY(get_foo());
The macro uses a GNU C++ extension which is supported by GCC, Clang,
Intel C++, and possibly others. It's not *ideal*, but since it makes our
codebase considerably nicer, let's try(!) it out. :^)
Co-authored-by: Ali Mohammad Pur <mpfard@serenityos.org>
This commit moves the KResult and KResultOr objects to Kernel/API to
signify that they may now be freely used by userspace code at points
where a syscall-related error result is to be expected. It also exposes
KResult and KResultOr to the global namespace to make it nicer to use
for userspace code.
This is the idiomatic way to declare type aliases in modern C++.
Flagged by Sonar Cloud as a "Code Smell", but I happen to agree
with this particular one. :^)
This function is currently only ever used to create the init process
(SystemServer). It had a few idiosyncratic things about it that this
patch cleans up:
- Errors were returned in an int& out-param.
- It had a path for non-0 process PIDs which was never taken.
REQUIRE_PROMISE and REQUIRE_NO_PROMISES were macros for some reason,
and used all over the place.
This patch adds require_promise(Pledge) and require_no_promises()
to Process and makes the macros call these on the current process
instead of inlining code everywhere.
freq_bin was converted to double after it was calculated, so there was
a much higher probability it could be 0 instead of some comma number,
which meant that the bars always stayed on top.
The freq_bin in bins_per_group was multiplied only to be divided later,
which could even result in a crash if you set higher buffer size
(like 1000ms) in PlaybackManager, due to rounding errors I presume.
Casting u64 to float is probably not a safe thing to do. Also, keep
time deltas in u64 values as they can easily wrap between calculations.
This fixes CPU usage calculation when a process is spinning in a loop.
Pior to this change when the user added text after having saved the file
the Text Editor wouldn't enable the modified flag, unless this new text
was a new line.
This happened because the UndoStack was merging the Command added by
the new text with the old text one, and when is_current_modified()
was called, the m_stack_index would not have been incremented, and
it would return false.
In this change was added a condition to verify if the modified tag is
active, and the merge is only done if the document is already modified.
Prior this change, opening a playlist always spawned a new widget.
This could end up with having a few the same widgets, which you couldn't
even close (besides the last one).
During conversion from Core::ConfigFile to LibConfig
in c646efaf49, the requested key name
has been changed from 'Mute' to 'Muted', resulting in using always
the default value.
According to the VirtIO 1.0 specification:
"Non-transitional devices SHOULD have a PCI Device ID in the range
0x1040 to 0x107f. Non-transitional devices SHOULD have a PCI Revision ID
of 1 or higher. Non-transitional devices SHOULD have a PCI Subsystem
Device ID of 0x40 or higher."
It also says that:
"Transitional devices MUST have a PCI Revision ID of 0. Transitional
devices MUST have the PCI Subsystem Device ID matching the Virtio
Device ID, as indicated in section 5. Transitional devices MUST have the
Transitional PCI Device ID in the range 0x1000 to 0x103f."
So, for legacy devices, we know that revision ID in the PCI header won't
be 1, so we probe for PCI_SUBSYSTEM_ID value.
Instead of using the subsystem device ID, we can probe the DEVICE_ID
value directly in case it's not a legacy device.
This should cover all possibilities for identifying VirtIO devices, both
per the specification of 0.9.5, and future revisions from 1.0 onwards.
We were incorrectly assuming that the mapped .text segment for an ELF
image was always at the base of the image mapping. Now that we have
.rodata mappings as well, it's possible for one of them to come before
the .text.
This function ensures that a key is present in the HashMap.
If it's not present, it is inserted, and the corresponding value
is initialized with whatever the callback returns.
It allows us to express this:
auto it = map.find(key);
if (it == map.end()) {
map.set(it, make_a_value());
it = map.find(key);
}
auto& value = it->value;
Like this:
auto& value = map.ensure(key, [] { return make_a_value(); });
Note that the callback is only invoked if we have to insert a missing
key into the HashMap. This is important in case constructing the default
value is expensive or otherwise undesirable.
It relies on a mapper function to convert each T& to a JS::Value. This
allows us to avoid awkward Vector<T> to MarkedValueList conversion at
the call site.
Without this, the bounding rect for the text as generated by TextLayout
can go beyond the bounds of the user-supplied drawing rect and cause the
text to overlap because of the line_rect.intersect(rect) a few lines
below.
