Gregory Terzian gterzian

Please show me a list of files that are screenshots, from a folder I can select.
Please review your code in the light of the guidelines, and fix it if necessary.
Now only show me a total for the size of all files previously found.

How to install and run an mini-app in Servo: Proof of Concept

Storage

Embedder use the filesystem as a cache for assets
Manifests also stored on the filesystem, but loaded in memory on start-up.

Registration

Mini-app registered with the embedder: store manifest and assets.

gterzian: Do

GitHub Copilot: To run the program, provide the number of images N and the number of threads NUM_THREADS as command-line arguments.

Usage:

cargo run -- <N> <NUM_THREADS>

Example:

gterzian: The current implementation seems to only process one image at a time, while the spec allows more than one image to be in the key, with the goal of generating keys in batches of more than one(on occasion).

If you agree that the spec allows for this, please change the logic accordingly.

GitHub Copilot: You are correct. The current implementation only ever puts one image into the PendingKey state at a time because the StartLoad action is only performed for a single image before the thread waits. This prevents the system from ever requesting a batch of more than one key, which defeats the purpose of the batching logic in the specification.

I have updated the code to allow a thread to perform multiple StartLoad actions in a single turn. This will allow multiple images to enter the PendingKey state, enabling the system to generate key batches as intended by the spec.

// ...existing code...

gterzian: The current implementation seems to only process one image at a time, while the spec allows more than one image to be in the key, with the goal of generating keys in batches of more than one(on occasion).

If you agree that the spec allows for this, please change the logic accordingly.

GitHub Copilot: You are correct. The current implementation only ever puts one image into the PendingKey state at a time because the StartLoad action is only performed for a single image before the thread waits. This prevents the system from ever requesting a batch of more than one key, which defeats the purpose of the batching logic in the specification.

I have updated the code to allow a thread to perform multiple StartLoad actions in a single turn. This will allow multiple images to enter the PendingKey state, enabling the system to generate key batches as intended by the spec.

// ...existing code...

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

	----------------------------- MODULE ImageEpoch -----------------------------
	EXTENDS FiniteSets, Integers
	CONSTANT N
	VARIABLES image, display_list, state, submitted
	-----------------------------------------------------------------------------
	Epoch == 0..N

	None == N+1

	TypeOk == /\ image \in {None} \cup Epoch