Added close_session (#762)

* Added close_session

* black

* Added implementation for closing a session + test

* add self url

---------

Co-authored-by: kevin-tian <[email protected]>

qiskit_ibm_provider/api/clients/runtime.py

@@ -317,3 +317,11 @@ def close_session(self, session_id: str) -> None:
             session_id (str): the id of the session to close
         """
         self._api.runtime_session(session_id=session_id).close()
+
+    def cancel_session(self, session_id: str) -> None:
+        """Cancel session
+
+        Args:
+            session_id (str): the id of the session to cancel
+        """
+        self._api.runtime_session(session_id=session_id).cancel()

qiskit_ibm_provider/api/rest/runtime_session.py

@@ -14,13 +14,16 @@
 
 
 from qiskit_ibm_provider.api.rest.base import RestAdapterBase
+from qiskit_ibm_provider.exceptions import IBMApiError
+from ..exceptions import RequestsApiError
 from ..session import RetrySession
 
 
 class RuntimeSession(RestAdapterBase):
     """Rest adapter for session related endpoints."""
 
     URL_MAP = {
+        "self": "",
         "close": "/close",
     }
 
@@ -37,6 +40,18 @@ def __init__(
         super().__init__(session, "{}/sessions/{}".format(url_prefix, session_id))
 
     def close(self) -> None:
-        """Close this session."""
+        """Set accepting_jobs flag to false, so no more jobs can be submitted."""
+        payload = {"accepting_jobs": False}
+        url = self.get_url("self")
+        try:
+            self.session.patch(url, json=payload)
+        except RequestsApiError as ex:
+            if ex.status_code == 404:
+                pass
+            else:
+                raise IBMApiError(f"Error closing session: {ex}")
+
+    def cancel(self) -> None:
+        """Cancel this session."""
         url = self.get_url("close")
         self.session.delete(url)

qiskit_ibm_provider/ibm_backend.py

@@ -883,6 +883,16 @@ def session(self) -> Session:
 
     def cancel_session(self) -> None:
         """Cancel session. All pending jobs will be cancelled."""
+        if self._session:
+            self._session.cancel()
+            if self._session.session_id:
+                self.provider._runtime_client.cancel_session(self._session.session_id)
+        self._session = None
+
+    def close_session(self) -> None:
+        """Close the session so new jobs will no longer be accepted, but existing
+        queued or running jobs will run to completion. The session will be terminated once there
+        are no more pending jobs."""
         if self._session:
             self._session.cancel()
             if self._session.session_id:

test/integration/test_session.py

@@ -62,14 +62,23 @@ def test_backend_run_with_session(self):
         )
 
     def test_session_cancel(self):
-        """Test closing a session"""
+        """Test canceling a session"""
         provider = IBMProvider(self.dependencies.token, self.dependencies.url)
         backend = provider.get_backend("ibmq_qasm_simulator")
         backend.open_session()
         self.assertTrue(backend.session.active)
         backend.cancel_session()
         self.assertIsNone(backend.session)
 
+    def test_session_close(self):
+        """Test closing a session"""
+        provider = IBMProvider(self.dependencies.token, self.dependencies.url)
+        backend = provider.get_backend("ibmq_qasm_simulator")
+        backend.open_session()
+        self.assertTrue(backend.session.active)
+        backend.close_session()
+        self.assertIsNone(backend.session)
+
     def test_run_after_cancel(self):
         """Test running after session is cancelled."""
         provider = IBMProvider(self.dependencies.token, self.dependencies.url)