Instead of sending while serializing (what even was that), we serialize
the whole packet into a buffer which can be sent in one go. First of all
this reduces the number of sends by a lot. This also fixes WindowServer
ending up sending partial packets when client is not responsive.
Previously we would just try sending once, if any send failed the send
was aborted while partial packet was already transmitted. This lead to
packet stream being out of sync leading to the client killing itself.
Now we allow 64 KiB outgoing buffer per client. If this buffer ever fills
up, we will not send partial packets.
Kernel syscall API no longer zeros all unused argument registers and
libc now uses inlined syscall macro internally. This significantly
cleans up generated code for basic syscall wrapper functions.
Instead of keeping track of the current time and rescheduling when
interval has passed, keep track of the next expected reschedule time.
This prevents theoretically missing every second pre-emption when
scheduler's timer is interrupting at same rate as the interval.
Install SIGCANCEL handler for all threads.
Remove unneeded atomic stores and loads. States are only changed within
the thread itself.
Define pthread_testcancel as a macro so it gets inlined inside
cancellation points
If the window does not have an alpha channel, we now set every pixel's
alpha to 0xFF. This is needed by the WindowServer when it does alpha
blending, there used to be some weird stuff happening on overlapping
windows.
Also when we are invalidating a region with width of the whole window,
we can do a single memcpy instead of a memcpy for each row separately.
Initially allocate all physical memory except kernel memory and boot
modules. Before we just skipped all memory before kernel boot modules.
Also release memory used by boot modules after the kernel is up and
running. Once the boot modules are loaded, there is no need to keep them
in memory.
We now appreciate sa_mask and SA_NODEFER and change the signal mask for
the duration of signal handler. This is done by making a sigprocmask
syscall at the end of the signal handler. Back-to-back signals will
still grow stack as original registers are popped AFTER the block mask
is updated. I guess this is why linux has sigreturn(?).
Current cpu index is stored at either segment. If userspace sets that
segment, kernel will not overwrite it on every reschedule. This is fine
as long as user program does not use anything that relies on it :)
We need to have interrupts enabled when signal kills the process as
process does mutex locking. Also signals are now only checked when
returning to userspace in the same place where userspace segments are
loaded.
