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2021-11-21Kernel: Share code between DoubleBuffer's read() and peek()Andreas Kling
The only difference between these is whether the buffer index is advanced after the read.
2021-11-08Kernel: Replace KResult and KResultOr<T> with Error and ErrorOr<T>Andreas Kling
We now use AK::Error and AK::ErrorOr<T> in both kernel and userspace! This was a slightly tedious refactoring that took a long time, so it's not unlikely that some bugs crept in. Nevertheless, it does pass basic functionality testing, and it's just real nice to finally see the same pattern in all contexts. :^)
2021-09-07Kernel: Make DoubleBuffer::try() return KResultOrAndreas Kling
This tidies up error propagation in a number of places.
2021-09-07Kernel: Remove redundant [[nodiscard]] on KResult return valuesAndreas Kling
Both KResult and KResultOr are [[nodiscard]] at the class level, so there's no need to have functions return `[[nodiscard]] KResult`.
2021-08-22Kernel+LibC: Implement FIONREAD ioctlPeter Elliott
FIONREAD gets the number of bytes availible to read from a file descriptor without blocking. I only implemented it for regular files and sockets
2021-08-07Kernel: Move Mutex into Locking/Jean-Baptiste Boric
2021-08-03Kernel: Remove OOM unsafe DoubleBuffer constructorBrian Gianforcaro
Remove this dangerous and now unused constructor.
2021-08-03Kernel: Add DoubleBuffer::try_create() factory method for OOM hardeningBrian Gianforcaro
We need to expose the ability for DoubleBuffer creation to expose failure, as DoubleBuffer depends on KBuffer, which also has to be able to expose failure during OOM. We will remove the non OOM API once all users have been converted.
2021-07-17Kernel: Rename Lock to MutexAndreas Kling
Let's be explicit about what kind of lock this is meant to be.
2021-06-16Kernel: Use KResultOr<size_t> for the DoubleBuffer classGunnar Beutner
2021-04-29Kernel: Implement peek() function for DoubleBufferJustin
This allows us to "peek" into a DoubleBuffer without incrementing the m_read_buffer_index, which is needed to implement MSG_PEEK.
2021-04-22Everything: Move to SPDX license identifiers in all files.Brian Gianforcaro
SPDX License Identifiers are a more compact / standardized way of representing file license information. See: https://spdx.dev/resources/use/#identifiers This was done with the `ambr` search and replace tool. ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt *
2021-02-23Everywhere: Rename ASSERT => VERIFYAndreas Kling
(...and ASSERT_NOT_REACHED => VERIFY_NOT_REACHED) Since all of these checks are done in release builds as well, let's rename them to VERIFY to prevent confusion, as everyone is used to assertions being compiled out in release. We can introduce a new ASSERT macro that is specifically for debug checks, but I'm doing this wholesale conversion first since we've accumulated thousands of these already, and it's not immediately obvious which ones are suitable for ASSERT.
2020-11-30Kernel: Move block condition evaluation out of the SchedulerTom
This makes the Scheduler a lot leaner by not having to evaluate block conditions every time it is invoked. Instead evaluate them as the states change, and unblock threads at that point. This also implements some more waitid/waitpid/wait features and behavior. For example, WUNTRACED and WNOWAIT are now supported. And wait will now not return EINTR when SIGCHLD is delivered at the same time.
2020-09-13Kernel: Make copy_to/from_user safe and remove unnecessary checksTom
Since the CPU already does almost all necessary validation steps for us, we don't really need to attempt to do this. Doing it ourselves doesn't really work very reliably, because we'd have to account for other processors modifying virtual memory, and we'd have to account for e.g. pages not being able to be allocated due to insufficient resources. So change the copy_to/from_user (and associated helper functions) to use the new safe_memcpy, which will return whether it succeeded or not. The only manual validation step needed (which the CPU can't perform for us) is making sure the pointers provided by user mode aren't pointing to kernel mappings. To make it easier to read/write from/to either kernel or user mode data add the UserOrKernelBuffer helper class, which will internally either use copy_from/to_user or directly memcpy, or pass the data through directly using a temporary buffer on the stack. Last but not least we need to keep syscall params trivial as we need to copy them from/to user mode using copy_from/to_user.
2020-08-04Kernel: Make File::write() and File::read() return KResultOr<size_t>Andreas Kling
Instead of returning a ssize_t where negative values mean error, we now return KResultOr<size_t> and use the error state to report errors exclusively.
2020-02-16Kernel: Move all code into the Kernel namespaceAndreas Kling
2020-01-20Kernel: Make DoubleBuffer use a KBuffer instead of kmalloc()ingAndreas Kling
Background: DoubleBuffer is a handy buffer class in the kernel that allows you to keep writing to it from the "outside" while the "inside" reads from it. It's used for things like LocalSocket and TTY's. Internally, it has a read buffer and a write buffer, but the two will swap places when the read buffer is exhausted (by reading from it.) Before this patch, it was internally implemented as two Vector<u8> that we would swap between when the reader side had exhausted the data in the read buffer. Now instead we preallocate a large KBuffer (64KB*2) on DoubleBuffer construction and use that throughout its lifetime. This removes all the kmalloc heap traffic caused by DoubleBuffers :^)
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.
2019-10-18Revert "Kernel: Make DoubleBuffer use a KBuffer instead of kmalloc()ing"Andreas Kling
This reverts commit 1cca5142afbd76833deedfdb238230ac53424855. This appears to be causing intermittent triple-faults and I don't know why yet, so I'll just revert it to keep the tree in decent shape.
2019-10-18Kernel: Make DoubleBuffer use a KBuffer instead of kmalloc()ingAndreas Kling
Background: DoubleBuffer is a handy buffer class in the kernel that allows you to keep writing to it from the "outside" while the "inside" reads from it. It's used for things like LocalSocket and PTY's. Internally, it has a read buffer and a write buffer, but the two will swap places when the read buffer is exhausted (by reading from it.) Before this patch, it was internally implemented as two Vector<u8> that we would swap between when the reader side had exhausted the data in the read buffer. Now instead we preallocate a large KBuffer (64KB*2) on DoubleBuffer construction and use that throughout its lifetime. This removes all the kmalloc heap traffic caused by DoubleBuffers :^)
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)
2019-05-02Kernel: Assign Lock names in class member initializers.Andreas Kling
2019-03-16Move Lock from AK to Kernel, since it only works inside the kernel.Andreas Kling
2019-02-25Kernel: Make syscalls that take a buffer size use ssize_t instead of size_t.Andreas Kling
Dealing with the unsigned overflow propagation here just seems unreasonably error prone. Let's limit ourselves to 2GB buffer sizes instead.
2019-02-07Kernel: When a lock is busy, donate remaining process ticks to lock holder.Andreas Kling
Since we know who's holding the lock, and we're gonna have to yield anyway, we can just ask the scheduler to donate any remaining ticks to that process.
2019-01-17Rename SpinLock to Lock. It hasn't been a SpinLock for some time.Andreas Kling
I'm pretty happy with the mechanism of AK::Lock for now.
2019-01-15Add internal locking to DoubleBuffer.Andreas Kling
2019-01-15Allow character devices to block write attempts until there is more space.Andreas Kling
2018-12-21Yet another pass of style fixes.Andreas Kling
2018-12-03Move DoubleBuffer to its own files.Andreas Kling