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2021-02-15Kernel: Mark Lock getters as [[nodiscard]]Brian Gianforcaro
There is no reason to call a getter without observing the result, doing so indicates an error in the code. Mark these methods as [[nodiscard]] to find these cases.
2021-01-25Everywhere: Use CMake to generate AK/Debug.h.asynts
This was done with the help of several scripts, I dump them here to easily find them later: awk '/#ifdef/ { print "#cmakedefine01 "$2 }' AK/Debug.h.in for debug_macro in $(awk '/#ifdef/ { print $2 }' AK/Debug.h.in) do find . \( -name '*.cpp' -o -name '*.h' -o -name '*.in' \) -not -path './Toolchain/*' -not -path './Build/*' -exec sed -i -E 's/#ifdef '$debug_macro'/#if '$debug_macro'/' {} \; done # Remember to remove WRAPPER_GERNERATOR_DEBUG from the list. awk '/#cmake/ { print "set("$2" ON)" }' AK/Debug.h.in
2021-01-15Kernel: Make Locker remember whether the lock is heldTom
This allows temporarily unlocking a lock or re-locking it, and it will only unlock if it is still being held. Fixes #4352
2021-01-04Kernel: Specify default memory order for some non-synchronizing AtomicsTom
2020-12-16Kernel: Fix Lock race causing infinite spinning between two threadsTom
We need to account for how many shared lock instances the current thread owns, so that we can properly release such references when yielding execution. We also need to release the process lock when donating.
2020-12-01Kernel: Fix some problems with Thread::wait_on and LockTom
This changes the Thread::wait_on function to not enable interrupts upon leaving, which caused some problems with page fault handlers and in other situations. It may now be called from critical sections, with interrupts enabled or disabled, and returns to the same state. This also requires some fixes to Lock. To aid debugging, a new define LOCK_DEBUG is added that enables checking for Lock leaks upon finalization of a Thread.
2020-11-30Kernel: Lock should keep a reference to whoever holds the lockTom
Fixes a crash reported in #3990
2020-04-30AK: Add ALWAYS_INLINE, NEVER_INLINE and FLATTEN macrosAndreas Kling
It's tedious to write (and look at) [[gnu::always_inline]] etc. :^)
2020-04-18Kernel: Introduce shared locking modeSergey Bugaev
A Lock can now be held either in shared or exclusive mode. Multiple threads can hold the same lock in shared mode at one time, but if any thread holds the lock in exclusive mode, no other thread can hold it at the same time in either mode.
2020-02-26Kernel: Allow process with multiple threads to call exec and exitCristian-Bogdan SIRB
This allows a process wich has more than 1 thread to call exec, even from a thread. This kills all the other threads, but it won't wait for them to finish, just makes sure that they are not in a running/runable state. In the case where a thread does exec, the new program PID will be the thread TID, to keep the PID == TID in the new process. This introduces a new function inside the Process class, kill_threads_except_self which is called on exit() too (exit with multiple threads wasn't properly working either). Inside the Lock class, there is the need for a new function, clear_waiters, which removes all the waiters from the Process::big_lock. This is needed since after a exit/exec, there should be no other threads waiting for this lock, the threads should be simply killed. Only queued threads should wait for this lock at this point, since blocked threads are handled in set_should_die.
2020-02-17Kernel: Replace "current" with Thread::current and Process::currentAndreas Kling
Suggested by Sergey. The currently running Thread and Process are now Thread::current and Process::current respectively. :^)
2020-02-16Kernel: Add forward declaration headerAndreas Kling
2020-02-16Kernel: Move all code into the Kernel namespaceAndreas Kling
2020-01-18Meta: Add license header to source filesAndreas Kling
As suggested by Joshua, this commit adds the 2-clause BSD license as a comment block to the top of every source file. For the first pass, I've just added myself for simplicity. I encourage everyone to add themselves as copyright holders of any file they've added or modified in some significant way. If I've added myself in error somewhere, feel free to replace it with the appropriate copyright holder instead. Going forward, all new source files should include a license header.
2020-01-13Kernel: Allow unlocking a held Lock with interrupts disabledAndreas Kling
This is needed to eliminate a race in Thread::wait_on() where we'd otherwise have to wait until after unlocking the process lock before we can disable interrupts.
2019-12-26Kernel: Add Lock::is_locked()Andreas Kling
2019-12-01Kernel: Add a WaitQueue for Thread queueing/waking and use it for LockAndreas Kling
The kernel's Lock class now uses a proper wait queue internally instead of just having everyone wake up regularly to try to acquire the lock. We also keep the donation mechanism, so that whenever someone tries to take the lock and fails, that thread donates the remainder of its timeslice to the current lock holder. After unlocking a Lock, the unlocking thread calls WaitQueue::wake_one, which unblocks the next thread in queue.
2019-10-12AK: Add Atomic.hTom
Use gcc built-in atomics
2019-07-29Kernel: Move Lock code out-of-line.Andreas Kling
It's so big and chunky anyway, it's silly to expand it everywhere. This makes it a lot easier to read function disassembly dumps.
2019-07-03AK: Rename the common integer typedefs to make it obvious what they are.Andreas Kling
These types can be picked up by including <AK/Types.h>: * u8, u16, u32, u64 (unsigned) * i8, i16, i32, i64 (signed)
2019-06-07Kernel: Move i386.{cpp,h} => Arch/i386/CPU.{cpp,h}Andreas Kling
There's a ton of work that would need to be done before we could spin up on another architecture, but let's at least try to separate things out a bit.
2019-05-28Add clang-format fileRobin Burchell
Also run it across the whole tree to get everything using the One True Style. We don't yet run this in an automated fashion as it's a little slow, but there is a snippet to do so in makeall.sh.
2019-05-16Kernel: Simplify dump_backtrace() API for clients.Andreas Kling
It makes no sense that clients had to worry about whether or not KSyms were loaded.
2019-05-14Kernel: Have Lock dump backtrace on lock-while-interrupts-disabled error.Andreas Kling
2019-04-17Kernel: Lock::unlock_if_locked() should never donate to holder.Andreas Kling
Since we're not interested in taking the lock if it's already held, there's no need to donate the remainder of our time slice to the holder.
2019-04-01Kernel: Add a blunt big process lock.Andreas Kling
We can't have multiple threads in the same process running in the kernel at the same time, so let's have a per-process lock that threads have to acquire on syscall entry/exit (and yield while blocked.)
2019-03-23Kernel: Introduce threads, and refactor everything in support of it.Andreas Kling
The scheduler now operates on threads, rather than on processes. Each process has a main thread, and can have any number of additional threads. The process exits when the main thread exits. This patch doesn't actually spawn any additional threads, it merely does all the plumbing needed to make it possible. :^)
2019-03-16Move Lock from AK to Kernel, since it only works inside the kernel.Andreas Kling