[Bug] Thread safety issues, unused variable, and deprecated logging in rf_mapper.py

[goblin0xcrypto]

Description

Found three issues in src/backgrounds/plugins/rf_mapper.py that need to be addressed for better code quality and thread safety.

Issues

1. 🔴 Thread Synchronization Problem (Critical)

File: src/backgrounds/plugins/rf_mapper.py

Problem:
Shared variables self.scan_results and self.scan_idx are accessed by two threads without proper synchronization, causing potential race conditions.

Current Code:

# In _scan_task (Thread 1) - Line 215
def _scan_task(self):
    while self.running:
        self.scan_results = self.loop.run_until_complete(self.scan())
        logging.info(f"RF scan index: {self.scan_idx}")
        self.scan_idx += 1  # ← Writing without lock

# In run (Thread 2) - Line 240
def run(self):
    while self.running:
        if self.scan_results and self.scan_idx > self.scan_last_sent:  # ← Reading without lock
            fresh_scan_results = self.scan_results
            self.scan_last_sent = self.scan_idx
            self.scan_results = []  # ← Race condition!

Impact:

• Data loss or corruption in scan results
• Inconsistent state between threads
• Unpredictable behavior

Proposed Fix:

# Add lock in __init__
self.scan_lock = threading.Lock()

# Protect writes in _scan_task
with self.scan_lock:
    self.scan_results = scan_results
    self.scan_idx += 1

# Protect reads in run
with self.scan_lock:
    if self.scan_results and self.scan_idx > self.scan_last_sent:
        fresh_scan_results = self.scan_results
        self.scan_results = []
        self.scan_last_sent = self.scan_idx

---

2. 🟡 Unused Variable

File: src/backgrounds/plugins/rf_mapper.py, Line 105

Problem:
Variable self.seen_names is declared but never used anywhere in the code.

Current Code:

self.seen_devices: Dict[str, RFData] = {}

self.seen_names: List[str] = []  # ← Never referenced

self.start()

Impact:

• Code clutter
• Confusing for maintainers
• Minor memory waste

Proposed Fix:
Remove the line entirely.

---

3. 🟡 Deprecated Logging Method

File: src/backgrounds/plugins/rf_mapper.py, Line 251

Problem:
Using logging.warn() which is deprecated since Python 3.3. Should use logging.warning() instead.

Current Code:

if g["ble_scan"] is not None:
    self.ble_scan = g["ble_scan"]
    logging.debug(f"RF scan results {self.ble_scan}")
else:
    logging.warn("No nRF52 scan results")  # ← Deprecated

Impact:

• Deprecation warnings in Python 3.10+
• May break in future Python versions
• Not following best practices

Proposed Fix:

logging.warning("No nRF52 scan results")

---

Environment

• Python Version: 3.10
• File: src/backgrounds/plugins/rf_mapper.py

[arsis69]

I found an additional bug in the same file that should be included:

Bug: self.sleep(1) - Method Does Not Exist

Location: src/backgrounds/plugins/rf_mapper.py, in the run() method

Problem: The code calls self.sleep(1) but the RFmapper class has no sleep() method. This will raise an AttributeError at
runtime, crashing the background process.

Current code:

self.sleep(1)  # we should send a payload every second

Fix:
time.sleep(1)  # we should send a payload every second

I'd like to submit a PR that fixes all four issues together:
1. self.sleep(1) → time.sleep(1) (runtime crash)
2. Thread safety with threading.Lock()
3. logging.warn() → logging.warning()
4. Remove unused self.seen_names