Commit graph

11 commits

Author SHA1 Message Date
Andreas Kling 94ca55cefd Meta: Add license header to source files
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.
2020-01-18 09:45:54 +01:00
Andreas Kling ec65b8db2e Revert "Kernel: Make DoubleBuffer use a KBuffer instead of kmalloc()ing"
This reverts commit 1cca5142af.

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.
2019-10-18 15:58:06 +02:00
Andreas Kling 1cca5142af Kernel: Make DoubleBuffer use a KBuffer instead of kmalloc()ing
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 :^)
2019-10-18 14:55:04 +02:00
Andreas Kling 27f699ef0c AK: Rename the common integer typedefs to make it obvious what they are.
These types can be picked up by including <AK/Types.h>:

* u8, u16, u32, u64 (unsigned)
* i8, i16, i32, i64 (signed)
2019-07-03 21:20:13 +02:00
Andreas Kling a02c945ef2 Kernel: DoubleBuffer can return early if read/write is called with !size. 2019-03-20 02:12:40 +01:00
Andreas Kling beda478821 Kernel: Make syscalls that take a buffer size use ssize_t instead of size_t.
Dealing with the unsigned overflow propagation here just seems unreasonably
error prone. Let's limit ourselves to 2GB buffer sizes instead.
2019-02-25 21:21:12 +01:00
Andreas Kling 9c51d9dfcd Catch anyone trying to use a DoubleBuffer with interrupts disabled. 2019-01-16 01:58:11 +01:00
Andreas Kling 52c004eb53 Add internal locking to DoubleBuffer. 2019-01-15 21:43:38 +01:00
Andreas Kling 3ac977f50b Paper over a race in DoubleBuffer.
I'm still somewhat okay throwing InterruptDisabler at races as they screw me.
Eventually I'm gonna have to devise a different strategy though.
2019-01-12 23:23:35 +01:00
Andreas Kling ec1c487dcd Yet another pass of style fixes. 2018-12-21 02:10:45 +01:00
Andreas Kling bbfae19238 Move DoubleBuffer to its own files. 2018-12-03 01:51:44 +01:00