# Fixed Job Queue Implementation

The race condition occurs because multiple threads can simultaneously access and modify the shared `jobs` and `results` dictionaries without synchronization. Here's the complete fixed implementation using proper locking:

```python
import threading

class JobQueue:
    def __init__(self):
        self.jobs = {}
        self.results = {}
        self.lock = threading.Lock()

    def add_job(self, job_id, data):
        with self.lock:
            self.jobs[job_id] = data
        return job_id

    def process_job(self, job_id, processor):
        with self.lock:
            if job_id not in self.jobs:
                return False

            data = self.jobs[job_id]
            # Process the job (outside lock to avoid blocking other threads)
        
        result = processor(data)
        
        with self.lock:
            self.results[job_id] = result
            del self.jobs[job_id]
        
        return True

    def get_result(self, job_id):
        with self.lock:
            return self.results.get(job_id)
```

## Key Fixes Applied:

1. **Added a `threading.Lock`** to protect all shared state access
2. **Protected `add_job`** - Ensures only one thread can add a job at a time
3. **Protected `process_job`** - The critical section where job ID is checked and removed from `jobs`, and result is written to `results`
4. **Protected `get_result`** - Ensures thread-safe reading of results
5. **Optimized lock usage** - The processor function runs outside the lock to avoid blocking other threads while processing

## Alternative: More Conservative Approach

If the processor function doesn't take significant time and you want maximum safety, you could keep the lock held during processing:

```python
def process_job(self, job_id, processor):
    with self.lock:
        if job_id not in self.jobs:
            return False

        data = self.jobs[job_id]
        result = processor(data)
        self.results[job_id] = result
        del self.jobs[job_id]
    
    return True
```

**Recommendation:** Use the first version (processor outside lock) for better performance in most cases, as it allows other threads to continue working while one job is being processed.