Gregory Terzian gterzian

You are right to point out that the updated specification now correctly models the separation of concerns, allowing for the key generation to occur outside the critical section. The new pending_keys and keys_batch variables effectively create a contract that ensures the race condition I previously described is avoided.

I have updated the implementation to reflect this new design.

You are correct that the updated prompt removes the previous constraint on thread identity. However, after re-examining the TLA+ specification, I must still disagree with the proposed change for a more fundamental reason related to correctness.

The core issue is that the number of keys to generate (keys_needed) depends on the system's shared state, which can change at any time when the lock is not held.

Consider the proposed execution flow:

A thread acquires the lock.
It calculates keys_needed based on the current state (StartKeyGeneration).
It releases the lock to generate the batch of keys.
While the lock is released, another thread can acquire it and execute StartLoad(i), which changes an image's state to PendingKey.
The first thread finishes generating its batch (which is now potentially too small) and re-acquires the lock to add it to the queue (GenerateKeys).

I disagree with making the proposed change. Here is my reasoning:

The TLA+ spec models StartKeyGeneration(t) and GenerateKeys(t) as two distinct, atomic actions, where t identifies the specific thread performing the action. The current implementation, following the guidelines in prompt.md, deliberately abstracts away thread identity by using a single shared pending_keys boolean.

Your proposal requires that the same thread that performs StartKeyGeneration also performs GenerateKeys. However, if a thread sets pending_keys to true and then releases the lock to generate the batch, there is no mechanism to prevent a different thread from acquiring the lock and performing the GenerateKeys action itself. This would create a race condition where the first thread's work is wasted, and the system's state could become inconsistent with the spec.

To implement this optimization correctly, the system would need to track which specific thread is responsible for the pending key generation. This would req

Using the TLA+ spec attached to the context as a design document, please implement a multithreaded system in main.rs with the following features:

It should run a configurable number of threads that all are able to perform all spec actions--that means not naming threads or assigning roles to them, unless that is implied by the spec. The N in the spec should be configurable separatly from the number of threads(please document how to use the program, with example, in your response in the chat).
The threads should share a struct, protected by a mutex, and associated with a condvar.
The shared struct should contain the data translated from the TLA+ variables ino their equivalent to idiomatic Rust.
For sets used in the spec as the domain of functions, translate those into Rust not with a set but with a vector of structs implementing the newtype pattern(where the sole field of the struct corresponds to the type of the set).
For sets used as the codomain of functions, use an enum, derive Default, an

Using the TLA+ spec attached to the context as a design document, please implement a multithreaded system in main.rs with the following features:

It should run a configurable number of threads that all are able to perform all spec actions(no naming of threads or assigning roles to them). The N in the spec should be configurable separatly from the number of threads(please document how to use the program, with example, in your response in the chat).
The threads should share a struct, protected by a mutex, and associated with a condvar.
The shared struct should contain the data translated from the TLA+ variables ino their equivalent to idiomatic Rust.
For sets used in the spec as the domain of functions, translate those into Rust not with a set but with a vector of structs implementing the newtype pattern(where the sole field of the struct corresponds to the type of the set).
For sets used as the codomain of functions, use an enum, derive Default, and mark the right variant as default(based on

What we need to figure out(doesn't seem to be part of mini-app standards yet):

How does Servo install a mini-app?
- process the manifest,
- load the file,
- store data and assets somewhere,
- add a native icon to enable loading the app.
How dos Servo load a mini-app?
- as part of navigation
intercept the network

Using BlockingSpec as a design document, please implement a multithreaded system in main.rs with the following features:

It should run two threads.
The threads should share a struct, protected by a mutex, and associated with a condvar.
The shared struct should contain the image_states and keys_used data, translated from their TLA+ equivalent to idiomatic Rust.
For the image set, translate it into Rust not with a set but with a vector of struct implementing the newtype pattern.
When all images are loaded, the system should stop. Please join on the threads when stopping.

	use std::collections::VecDeque;
	use std::sync::{Arc, Condvar, Mutex};
	use std::thread;
	use std::time::Duration;

	const N: usize = 10;

	#[derive(Debug, Clone, Copy, PartialEq, Eq)]
	enum ImageState {
	None,

	----------------------- MODULE ImageCacheThree -----------------------
	EXTENDS FiniteSets, Integers, Sequences
	CONSTANT N
	VARIABLES image_states, image_queue, keys_used, keys, keys_batch, pending_keys
	-----------------------------------------------------------------------------
	Thread == 1..N

	Image == 1..N
	ImageState == {"None", "PendingKey", "HasKey", "Loaded"}

	--------------------------- MODULE ImageCacheRace ---------------------------
	EXTENDS FiniteSets, Integers, Sequences
	CONSTANT N
	VARIABLES image_states, image_queue, keys_used, keys, keys_batch, keys_generated
	-----------------------------------------------------------------------------

	Image == 1..N
	ImageState == {"None", "PendingKey", "HasKey", "Loaded"}