Due to the asynchronous nature of main-thread tasks, it's possible for
them to be executed on peripherals which have been detached. This has
been known for a long time (#893 was opened back in 2021), but finding a
good solution here is tricky.
Most of the time the method will silently succeed, but if we try to
interact with an IComputerAccess (such as in inventory methods, as seen
in #1750), we throw a NotAttachedException exception and spam the logs!
This is an initial step towards fixing this - when calling a peripheral
method via peripheral.call/modem.callRemote, we now wrap any enqueued
main-thread tasks and silently skip them if the peripheral has been
detached since.
This means that peripheral methods may start to return nil when they
didn't before. I think this is *fine* (though not ideal for sure!) - we
return nil if the peripheral has been detached, so it's largely
equivalent to that.
Double chests peripherals were getting reattached every time there was a
block update, as the inventories were not comparing equal (despite being
so!). We now check for a couple of common cases, which should be enough
for vanilla/vanilla-like inventories.
I actively Do Not Like This Code, but do not see a good alternative.
This should never happen, but apparently it does!? We now log an error
(rather than crashing), and include the original BE (and associated
block), as the BE type isn't very useful.
See #1750. Technically this fixes it, but want to do some more poking
there first.
Here's a fun bug you can try at home:
- Create a new world
- Spawn in a pocket computer, turn it on, and place it in a chest.
- Reload the world - the pocket computer in the chest should now be
off.
- Spawn in a new pocket computer, and turn it on. The computer in chest
will also appear to be on!
This bug has been present since pocket computers were added (27th March,
2024).
When a pocket computer is added to a player's inventory, it is assigned
a unique *per-session* "instance id" , which is used to find the
associated computer. Note the "per-session" there - these ids will be
reused if you reload the world (or restart the server).
In the above bug, we see the following:
- The first pocket computer is assigned an instance id of 0.
- After reloading, the second pocket computer is assigned an instance
id of 0.
- If the first pocket computer was in our inventory, it'd be ticked and
assigned a new instance id. However, because it's in an inventory, it
keeps its old one.
- Both computers look up their client-side computer state and get the
same value, meaning the first pocket computer mirrors the second!
To fix this, we now ensure instance ids are entirely unique (not just
per-session). Rather than sequentially assigning an int, we now use a
random UUID (we probably could get away with a random long, but this
feels more idiomatic).
This has a couple of user-visible changes:
- /computercraft no longer lists instance ids outside of dumping an
individual computer.
- The @c[instance=...] selector uses UUIDs. We still use int instance
ids for the legacy selector, but that'll be removed in a later MC
version.
- Pocket computers now store a UUID rather than an int.
Related to this change (I made this change first, but then they got
kinda mixed up together), we now only create PocketComputerData when
receiving server data. This makes the code a little uglier in some
places (the data may now be null), but means we don't populate the
client-side pocket computer map with computers the server doesn't know
about.
- Remove "initial connections" flag, and just refresh connections +
peripherals on the first tick.
- Remove "peripheral attached" from NBT, and just read/write it from
the block state. This might cause issues with #1010, but that's
sufficiently old I hope it won't!
Our GatedPredicate hack was clever, but also fundamentally didn't work.
The predicate is called before extraction, so if extraction fails (for
instance, canTakeItemThroughFace returns false), then we still think an
item has been removed.
To fix that, we inline StorageUtil.move, specialising it for what we
need.
This feels a little overkill, but nice to standardise how this code
looks.
There's a bit of me which wonders if we should remove
IPeripheral.equals, and just use Object.equals, but I do also kinda like
the explicitness of the current interface? IDK.
This ensures the client decoder is in sync with the server. Well, mostly
- we don't handle the anti-jerk, but that should correct itself within a
few samples.
Fixes#1748
The original runtime error reporting PR[^1] added a "cc.exception"
module, which allowed coroutine managers (such as parallel) to throw
rich errors, detailing the original context where the error was thrown.
Unfortunately, the change to parallel broke some programs (>_>, don't do
string pattern matching on your errors!), and so had to be reverted,
along with the cc.exception module.
As a minimal replacement for this, we add support for user-thrown
exceptions within our internal code. If an error object "looks" like an
exception ("exception" __name, and a message and thread field), then we
use that as our error information instead.
This is currently undocumented (at least in user-facing documentation),
mostly because I couldn't figure out where to put it - the interface
should remain stable.
[^1]: https://github.com/cc-tweaked/CC-Tweaked/pull/1320
This adds support for computer selectors, in the style of entity
selectors. The long-term goal here is to replace our existing ad-hoc
selectors. However, to aid migration, we currently support both - the
previous one will most likely be removed in MC 1.21.
Computer selectors take the form @c[<key>=<value>,...]. Currently we
support filtering by id, instance id, label, family (as before) and
distance from the player (new!). The code also supports computers within
a bounding box, but there's no parsing support for that yet.
This commit also (finally) documents the /computercraft command. Well,
sort of - it's definitely not my best word, but I couldn't find better
words.
When rendering non-origin monitors, we would fetch the origin monitor,
read its client state, and then cache that on the current monitor to
avoid repeated lookups.
However, if the origin monitor is unloaded/removed on the client, and
then loaded agin, this cache will be not be invalidated, causing us to
render both the old and new monitor!
I think the correct thing to do here is cache the origin monitor. This
allows us to check when the origin monitor has been removed, and
invalidate the cache if needed.
However, I'm wary of any other edge cases here, so for now we do
something much simpler, and remove the cache entirely. This does mean
that monitors now need to perform extra block entity lookups, but the
performance cost doesn't appear to be too bad.
Fixes#1741
Historically, computers tracked whether any world-visible state
(on/off/blinking, label and redstone outputs) had changed with a single
"has changed" flag. While this is simple to use, this has the curious
side effect of that term.setCursorBlink() or os.setComputerLabel() would
cause a block update!
This isn't really a problem in practice - it just means slightly more
block updates. However, the redstone propagation sometimes causes the
computer to invalidate/recheck peripherals, which masks several other
(yet unfixed) bugs.
- colors.toBlit now performs bounds checks on the passed value,
preventing weird behaviour like color.toBlit(2 ^ 16) returning "10".
- The window API now uses colors.toBlit (or rather a copy of it) for
parsing colours, allowing doing silly things like
term.setTextColour(colours.blue + 5).
- Add some top-level documentation to the term API to explain some of
the basics.
Closes#1736
Minecraft sometimes keeps chunks in-memory, but not actively loaded. If
we schedule a block entity to be ticked and that chunk is is then
transitioned to this partially-loaded state, then the block entity is
never actually ticked.
This is most visible with monitors. When a monitor's contents changes,
if the monitor is not already marked as changed, we set it as changed
and schedule a tick (see ServerMonitor). However, if the tick is
dropped, we don't clear the changed flag, meaning subsequent changes
don't requeue the monitor to be ticked, and so the monitor is never
updated.
We fix this by maintaining a list of block entities whose tick was
dropped. If these block entities (or rather their owning chunk) is ever
re-loaded, then we reschedule them to be ticked.
An alternative approach here would be to add the scheduled tick directly
to the LevelChunk. However, getting hold of the LevelChunk for unloaded
blocks is quiet nasty, so I think best avoided.
Fixes#1146. Fixes#1560 - I believe the second one is a duplicate, and
I noticed too late :D.
When we remove a wired node from a network, we need to find connected
components in the rest of the graph. Typically, this requires a
traversal of the whole graph, taking O(|V| + |E|) time.
If we remove a lot of nodes at once (such as when unloading chunks),
this ends up being quadratic in the number of nodes. In some test
networks, this can take anywhere from a few seconds, to hanging the game
indefinitely.
This attempts to reduce the cases where this can happen, with a couple
of optimisations:
- Instead of constructing a new hash set of reachable nodes (requiring
multiple allocations and hash lookups), we store reachability as a
temporary field on the WiredNode.
- We abort our traversal of the graph if we can prove the graph remains
connected after removing the node.
There's definitely future work to be done here in optimising large wired
networks, but this is a good first step.
- Replace usages of WiredNetwork.connect/disconnect/remove with the
WiredNode equivalents.
- Convert "testLarge" into a proper JMH benchmark.
- Don't put a peripheral on every node in the benchmarks. This isn't
entirely representative, and means the peripheral juggling code ends
up dominating the benchmark time.
We've been out-of-date for a while now, as we needed to update
lua_menhir to work with lrgrep 3.
- Better handling of standalone names/expressions - we now correctly
handle lists of names.
- Handle missing commas in tables in a few more places.
- We checked the backing array when reading rather than the file's
length, so could read beyond the end of the file.
- We used the entry length when resizing, which effectively meant we
doubled the size of the backing array on each write.
- cc.require now uses the internal _LOADED table to get the list of
built-in globals. This fixes several globals not showing up on the
list (e.g. utf8), and allows us to inject more modules from the Java
side.
- ILuaAPI now has a getModuleName() function. This is used to inject
the API into the aforementioned _LOADED table, allowing it to be
"require"d.
One common issue we get when a program exits after handling a "key"
event is that it leaves the "char" event on the queue. This means that
the shell (or whatever program we switch in to) then receives the "char"
event, often displaying it to the screen.
Previously we've got around this by doing sleep(0) before exiting the
program. However, we also see this problem in edit's run handler script,
and I'm less comfortable doing the same hack there.
This adds a new internal discard_char function, which will either
wait one tick or return when seeing a char/key_up event.
Fixes#1705
- Mark our core test-fixtures jar as part of the "cctest", rather than
a separate library. I'm fairly sure this was actually using the
classpath version of CC rather than the legacyClasspath version!
- Add a new "testMinecraftLibrary" configuration, instead of trying to
infer it from the classpath. We have to jump through some hoops to
avoid having multiple versions of a library on the classpath at once,
but it's not too bad.
I'm working on a patch to bsl which might allow us to kill of
legacyClasspath instead. Please, anything is better than this.
Forge doesn't run client-side commands from sendUnsignedCommand, so we
still require a mixin there.
We do need to change the command name, as Fabric doesn't properly merge
the two command trees.
I didn't make a new years resolution to stop writing build tooling, but
maybe I should have.
This replaces our use of VanillaGradle with a new project,
VanillaExtract. This offers a couple of useful features for multi-loader
dev, including Parchment and Unpick support, both of which we now use in
CC:T.
- Debug hooks are now correctly called for every function.
- Fix several minor inconsistencies with debug.getinfo.
- Fix Lua tables being sized incorrectly when created from varargs.
- Update FG to 6.0.20 - no major changes, but required for the Gradle
update.
- Update Loom to 1.5.x - this adds Vineflower support by default, so we
can remove loom-vineflower.
This was copied over from the old binary handle, and so states we
always return a single number if no count is given. This is only the
case when the file is opened in binary mode.
Rather than mixing-in to CachedOutput, we just wrap our DataProviders to
use a custom CachedOutput which reformats the JSON before writing. This
allows us to drop mixins for common+non-client code.
Disk drives have had a long-standing issue with mutating their contents
on the computer thread, potentially leading to all sorts of odd bugs.
We tried to fix this by moving setDiskLabel and the mounting code to run
on the main thread. Unfortunately, this means there is a slight delay to
mounts being attached, breaking disk startup.
This commit implements an alternative solution - we now do mounting on
the computer thread again. If the disk's stack is modified, we update it
in the peripheral-facing item, but not the actual inventory. The next
time the disk drive is ticked, we then sync the two items.
This does mean that there is a fraction of a tick where the two will be
out-of-sync. This isn't ideal - it would potentially be possible to
cycle through disk ids - but I don't really think that's avoidable
without significantly complicating the IMedia API.
Fixes#1649, fixes#1686.
