Internally, before a connection is returned from a pool, check for

control packets from the server (which may inform the client that the
connection needs to be closed and a new one established).

Author: anthony-tuininga

doc/src/release_notes.rst

@@ -23,6 +23,9 @@ Thin Mode Changes
     the database sends a password challenge with a verifier type that is not
     recognized, instead of `ORA-01017: invalid username/password`
     (`issue 26 <https://github.com/oracle/python-oracledb/issues/26>`__).
+#)  Internally, before a connection is returned from a pool, check for control
+    packets from the server (which may inform the client that the connection
+    needs to be closed and a new one established).
 #)  Internally make use of the `TCP_NODELAY` socket option to remove delays
     in socket reads.
 

src/oracledb/impl/thin/buffer.pyx

@@ -1081,6 +1081,21 @@ cdef class ReadBuffer:
 
         return bytes(output_value).decode()
 
+    cdef int check_control_packet(self) except -1:
+        """
+        Checks for a control packet or final close packet from the server.
+        """
+        cdef:
+            uint8_t packet_type, packet_flags
+            uint16_t data_flags
+        self._receive_packet_helper(&packet_type, &packet_flags)
+        if packet_type == TNS_PACKET_TYPE_CONTROL:
+            self._process_control_packet()
+        elif packet_type == TNS_PACKET_TYPE_DATA:
+            self.read_uint16(&data_flags)
+            if data_flags == TNS_DATA_FLAGS_EOF:
+                self._session_needs_to_be_closed = True
+
     cdef int receive_packet(self, uint8_t *packet_type,
                             uint8_t *packet_flags) except -1:
         """

src/oracledb/impl/thin/constants.pxi

@@ -42,6 +42,9 @@ DEF TNS_PACKET_TYPE_REDIRECT = 5
 # packet flags
 DEF TNS_PACKET_FLAG_TLS_RENEG = 0x08
 
+# data flags
+DEF TNS_DATA_FLAGS_EOF = 0x0040
+
 # marker types
 DEF TNS_MARKER_TYPE_BREAK = 1
 DEF TNS_MARKER_TYPE_RESET = 2