Marcus/API/zmq_api.py

86 lines
2.7 KiB
Python

"""
zmq_api.py — ZMQ velocity + command interface to Holosoma
Previously the PUB socket was bound at module import time. That made the
module unsafe to re-import from any multiprocessing child (e.g. the LiDAR
SLAM_worker spawn), because the child would try to rebind the same port
and crash with `Address already in use`.
The bind now lives in init_zmq() — call it once from the brain entrypoint.
Child processes can import this module without any network side effects.
"""
import json
import os
import time
import zmq
from Core.config_loader import load_config
from Core.logger import log
_cfg = load_config("ZMQ")
ZMQ_HOST = _cfg["zmq_host"]
ZMQ_PORT = _cfg["zmq_port"]
STOP_ITERATIONS = _cfg["stop_iterations"]
STOP_DELAY = _cfg["stop_delay"]
STEP_PAUSE = _cfg["step_pause"]
# Shared state. These stay None until init_zmq() is called.
ctx: zmq.Context = None
sock: zmq.Socket = None
_INIT_SETTLE = 0.5 # seconds to let PUB tell subscribers it's alive
def init_zmq() -> zmq.Socket:
"""
Bind the PUB socket. Idempotent — safe to call more than once.
Call from the main (parent) process only. Do NOT call from multiprocessing
children — they inherit nothing useful from the bound socket anyway.
"""
global ctx, sock
if sock is not None:
return sock
ctx = zmq.Context()
sock = ctx.socket(zmq.PUB)
sock.bind(f"tcp://{ZMQ_HOST}:{ZMQ_PORT}")
time.sleep(_INIT_SETTLE)
log(f"ZMQ PUB bound on tcp://{ZMQ_HOST}:{ZMQ_PORT} (pid={os.getpid()})",
"info", "zmq")
return sock
def _ensure_sock() -> zmq.Socket:
if sock is None:
raise RuntimeError(
"zmq_api not initialized — call init_zmq() from the brain "
"entrypoint before using send_vel/send_cmd/gradual_stop"
)
return sock
def get_socket():
"""Return the shared ZMQ PUB socket (for odometry to reuse)."""
return _ensure_sock()
def send_vel(vx: float = 0.0, vy: float = 0.0, vyaw: float = 0.0):
"""Send velocity to Holosoma. vx m/s | vy m/s | vyaw rad/s"""
_ensure_sock().send_string(json.dumps({"vel": {"vx": vx, "vy": vy, "vyaw": vyaw}}))
def gradual_stop():
"""Smooth deceleration to zero over ~1 second."""
s = _ensure_sock()
for _ in range(STOP_ITERATIONS):
s.send_string(json.dumps({"vel": {"vx": 0.0, "vy": 0.0, "vyaw": 0.0}}))
time.sleep(STOP_DELAY)
def send_cmd(cmd: str):
"""Send Holosoma state command: start | walk | stand | stop"""
_ensure_sock().send_string(json.dumps({"cmd": cmd}))
# Load MOVE_MAP from navigation config (pure data, safe at import time)
_nav = load_config("Navigation")
MOVE_MAP = {k: tuple(v) for k, v in _nav["move_map"].items()}