improved logging

python_app/orchestration/shm/ring_reader.py

@@ -2,6 +2,7 @@
 
 from __future__ import annotations
 
+import logging
 import mmap
 from pathlib import Path
 import struct
@@ -16,6 +17,8 @@ from python_app.orchestration.shm.decoder import (
     decode_trace_collection,
 )
 
+logger = logging.getLogger(__name__)
+
 _HEADER_SIZE: Final[int] = 64
 _SLOT_HEADER_SIZE: Final[int] = 16
 _MAGIC: Final[bytes] = b"RDRRING2"
@@ -43,6 +46,12 @@ class ShmRingReader:
             # A fail-fast open (absent/incompatible ring) must not leak the fd/mapping.
             self.close()
             raise
+        logger.debug(
+            "Opened SHM ring reader %s (capacity=%d, slot_size=%d bytes)",
+            self._ring_name,
+            self.capacity,
+            self.slot_size_bytes,
+        )
 
     def close(self) -> None:
         """Close mmap and file handle."""
@@ -50,6 +59,7 @@ class ShmRingReader:
             self._mmap.close()
             self._mmap = None
         self._file.close()
+        logger.debug("Closed SHM ring reader %s", self._ring_name)
 
     def pop_payload(self) -> bytes | None:
         """Read next payload from ring, or `None` if no unread payload exists."""
@@ -68,6 +78,7 @@ class ShmRingReader:
         sequence = self._read_u64(slot_offset + 8)
         if sequence != read_seq + 1:
             # Producer overwrote this slot before we read it. Resync to latest.
+            logger.debug("Ring %s: slot lapped before read, resyncing to write_seq=%d", self._ring_name, write_seq)
             self._write_u64(32, write_seq)
             return None
 
@@ -75,6 +86,12 @@ class ShmRingReader:
         # Bound payload_size against the slot before slicing so a torn/garbage size
         # can never read out of the slot region; resync and skip on violation.
         if payload_size > self.slot_size_bytes:
+            logger.debug(
+                "Ring %s: payload_size %d exceeds slot %d, resyncing",
+                self._ring_name,
+                payload_size,
+                self.slot_size_bytes,
+            )
             self._write_u64(32, write_seq)
             return None
 
@@ -84,6 +101,7 @@ class ShmRingReader:
         # Re-read the slot sequence after the copy; if it changed, the producer
         # overwrote this slot mid-copy and the payload is torn — discard and resync.
         if self._read_u64(slot_offset + 8) != read_seq + 1:
+            logger.debug("Ring %s: slot overwritten mid-copy, discarding torn payload", self._ring_name)
             self._write_u64(32, write_seq)
             return None
 
@@ -158,6 +176,7 @@ class ShmRingReader:
             return 0
         dropped = int(write_seq - read_seq)
         self._write_u64(32, write_seq)
+        logger.debug("Ring %s: dropped %d unread payload(s)", self._ring_name, dropped)
         return dropped
 
     @property