This should help prevent deadlocks where a thread blocks on a Mutex
while interrupts are disabled, and makes it impossible for the holder of
the Mutex to make forward progress because it cannot be scheduled in.
Hide it behind a new debug macro LOCK_IN_CRITICAL_DEBUG for now, because
Ext2FS takes a series of Mutexes from the page fault handler, which
executes with interrupts disabled.
Previously, we would try to acquire a reference to the all processes
lock or other contended resources while holding both the scheduler lock
and the thread's blocker lock. This could lead to a deadlock if we
actually have to block on those other resources.
There are callers of processes().with or processes().for_each that
require interrupts to be disabled. Taking a Mutexe with interrupts
disabled is a recipe for deadlock, so convert this to a Spinlock.
There's no need to disable interrupts when trying to access an inode's
shared vmobject. Additionally, Inode::shared_vmobject() acquires a Mutex
which is a recipe for deadlock if acquired with interrupts disabled.
Optimizations:
- Make sure `DT_SYMTAB` is a string view literal, instead of string.
- DynamicObject::HashSection::lookup_sysv_symbol should be using
raw_name() from symbol comparison to avoid needlessly calling
`strlen`, when the StrinView::operator= walks the cstring without
calling `strlen` first.
- DynamicObject::HashSection::lookup_gnu_symbol shouldn't create a
symbol unless we know the hashes match first.
In order to test these changes I enabled Undefined behavior sanitizer
which creates a huge amount of relocations, and then ran the browser
with the help argument 100 times. The browser is a fairly big app with
a few different libraries being loaded, so it seemed liked a good
target.
Command: `time -n 100 br --help`
Before:
```
Timing report:
==============
Command: br --help
Average time: 3897.679931 ms
Excluding first: 3901.242431 ms
```
After:
```
Timing report:
==============
Command: br --help
Average time: 3612.860107 ms
Excluding first: 3613.54541 ms
```
The kernel profiles were recently changed to have a `strings` array
as part of the profile objects. The `ProfileViewer` now checks for
that during startup and declares the profile invalid if the array
is not present.
The UserspaceEmulator doesn't use the API which the kernel exposed
the string array for, so just fake it by always adding an empty array
to the generated profiles.
The fact that profiles are json on one giant line makes them very
difficult to debug when things go wrong. Instead make sure to wrap
each event or sample on a newline so you can easily grep/heap/tail
the profile files.
This kinda sorta addresses the Shell side of #9655, however the fact
that `chdir` (and most other syscalls that take paths) are artifically
limited to a length of PATH_MAX remains.
I locally modified Meta/serenity.sh to pass `--dev` to BuildIt.sh
in build_toolchain(). Then I ran `Meta/serenity.sh rebuild-toolchain`,
cd'd into Toolchain/Tarballs/binutils-2.37, `git add`ed unadded files in
`git status`, and then ran `git diff > ../../Patches/binutils.patch`.
Then I did the same for Toolchain/Tarballs/gcc-11.2.0 (and was careful
not to `git add` serenity-kernel.h, since that's created by
Toolchain/BuildIt.sh).
No behavior change. This just rewrites the patch like git writes it.
I think this *should* be working as-is, but there's probably something
wrong with the this value of native functions. Either way, not relying
on the implicit this value will allow us to use strict mode here
eventually.
Fixes#9240.
This adds a `-q` option, which expects a comma-separated list of PIDs as
a value. On using it, only the processes associated with the supplied
PIDs are output.
This environment variable is already widely used across our build
scripts and tooling, so serenity.sh should respect it as well.
It still uses i686 as the fallback.
This allows us to remove all the add_subdirectory calls from the top
level CMakeLists.txt that referred to targets linking LagomCore.
Segregating the host tools and Serenity targets helps us get to a place
where the main Serenity build can simply use a CMake toolchain file
rather than swapping all the compiler/sysroot variables after building
host libraries and tools.
Gather the custom commands for each of the 6 bindings generated targets
for libjs_js_wrapper invocations into some lists so that we can foreach
over the lists instead of having 6 copy pasted commands with one or two
things modified for each one.
Additional refactoring, use target_sources command to inform CMake about
additional source files for LibWeb, but only after it's been declared as
a library via add_library. Also avoid use of the write_if_different
script and use cmake -E copy_if_different instead. This lets us express
the actions in rules that CMake understands without going to an external
source file. It exposes a few optimization opportunities for the code
generators to accept an output filename instead of always going to
stdout.
Moving this helper CMake file to the centralized Meta/CMake folder helps
to get a better grasp on what extra files are required for the build,
and what files are generated.
While we're at it, don't use add_compile_definitions for
ENABLE_UNICODE_DATA, which only needs to be seen by LibUnicode sources.
By using SerenityOS_SOURCE_DIR we can make custom targets and commands
agnostic to the actual location of the root CMakeLists directory.
All we care about is the root of the SerenityOS project.
compile_gml, compile_ipc, and generate_state_machine all use host
tools to generate sources for the target build. As part of trying to
organize host tools into a common area, let's move these helper rules to
a common file that we can add other host tools to later. And, keep the
host tool helpers separate from the CMake target helpers for apps and
libraries.
It's hard to follow how all the functions in the utils.cmake helper file
flow together, so let's move the pieces that are related to each other
into specialized helpers. First up: all the ConfigureComponents related
properties and functions.
