azy-init shared context instead of one per port

Author: GREENRAT-K405

concore_base.py

@@ -11,17 +11,28 @@
 # ===================================================================
 # ZeroMQ Communication Wrapper
 # ===================================================================
-# single shared ZMQ context for the entire process.
-_zmq_context = zmq.Context()
+# lazy-initialized shared ZMQ context for the entire process.
+# using None until first ZMQ port is created, so file-only workflows
+# never spawn ZMQ I/O threads at import time.
+_zmq_context = None
+
+def _get_zmq_context():
+    """Return the process-level shared ZMQ context, creating it on first call."""
+    global _zmq_context
+    if _zmq_context is None or _zmq_context.closed:
+        _zmq_context = zmq.Context()
+    return _zmq_context
 
 class ZeroMQPort:
-    def __init__(self, port_type, address, zmq_socket_type, context):
+    def __init__(self, port_type, address, zmq_socket_type, context=None):
         """
         port_type: "bind" or "connect"
         address: ZeroMQ address (e.g., "tcp://*:5555")
         zmq_socket_type: zmq.REQ, zmq.REP, zmq.PUB, zmq.SUB etc.
-        context: shared zmq.Context() for the process
+        context: optional zmq.Context() for the process; defaults to the shared _zmq_context.
         """
+        if context is None:
+            context = _get_zmq_context()
         self.socket = context.socket(zmq_socket_type)
         self.port_type = port_type  # "bind" or "connect"
         self.address = address
@@ -79,7 +90,7 @@ def init_zmq_port(mod, port_name, port_type, address, socket_type_str):
     try:
         # Map socket type string to actual ZMQ constant (e.g., zmq.REQ, zmq.REP)
         zmq_socket_type = getattr(zmq, socket_type_str.upper())
-        mod.zmq_ports[port_name] = ZeroMQPort(port_type, address, zmq_socket_type, _zmq_context)
+        mod.zmq_ports[port_name] = ZeroMQPort(port_type, address, zmq_socket_type, _get_zmq_context())
         logger.info(f"Initialized ZMQ port: {port_name} ({socket_type_str}) on {address}")
     except AttributeError:
         logger.error(f"Error: Invalid ZMQ socket type string '{socket_type_str}'.")
@@ -108,11 +119,15 @@ def terminate_zmq(mod):
             logger.error(f"Error while terminating ZMQ port {port.address}: {e}")
     mod.zmq_ports.clear()
 
-    # terminate the single shared context exactly once.
-    try:
-        _zmq_context.term()
-    except Exception as e:
-        logger.error(f"Error while terminating shared ZMQ context: {e}")
+    # terminate the single shared context exactly once, then reset so it
+    # can be safely recreated if init_zmq_port is called again later.
+    global _zmq_context
+    if _zmq_context is not None and not _zmq_context.closed:
+        try:
+            _zmq_context.term()
+        except Exception as e:
+            logger.error(f"Error while terminating shared ZMQ context: {e}")
+        _zmq_context = None
 
     mod._cleanup_in_progress = False