Back to all reviewers

Prevent async race conditions

discourse/discourse
Based on 2 comments
Other

When handling multiple concurrent async operations (like user input triggering API calls or messageBus updates), implement mechanisms to prevent race conditions where stale results could overwrite newer state.

Concurrency Other

Reviewer Prompt

When handling multiple concurrent async operations (like user input triggering API calls or messageBus updates), implement mechanisms to prevent race conditions where stale results could overwrite newer state.

Use request IDs to track and validate async operations:

async fetchSuggestions() {
  const input = this.currentInputValue || "";
  const requestId = ++this.suggestionRequestId;
  
  const results = await this.suggester.search(input);
  
  // Only process if this is still the latest request
  if (requestId === this.suggestionRequestId) {
    this.suggestions = results;
  }
}

Alternatively, use AbortController to cancel outdated requests:

async fetchSuggestions() {
  // Cancel previous request
  if (this.abortController) {
    this.abortController.abort();
  }
  
  this.abortController = new AbortController();
  const results = await this.suggester.search(input, { 
    signal: this.abortController.signal 
  });
  
  this.suggestions = results;
}

This prevents scenarios where fast user interactions or component state changes could result in displaying incorrect data from slower, outdated async operations.

2
Comments Analyzed
Other
Primary Language
Concurrency
Category

Source Discussions