SERVER-65505 Make the gdb pretty printers for Session/TransactionParticipant work with the latest version of the SessionCatalog

(cherry picked from commit 53eaaa11e4e19029a714c2db6d243af3b5fbbd68)

1 files changed, 124 insertions, 87 deletions

diff --git a/buildscripts/gdb/mongo.py b/buildscripts/gdb/mongo.py
index b39d08a77c1..6ad24bf9a85 100644
--- a/buildscripts/gdb/mongo.py
+++ b/buildscripts/gdb/mongo.py
@@ -318,75 +318,100 @@ class DumpMongoDSessionCatalog(gdb.Command):
         else:
             lsids_to_print = [str(s['first']['_id']) for s in session_kv_pairs]
 
-        for sess_kv in session_kv_pairs:
-            # The Session is stored inside the SessionRuntimeInfo object.
-            session_runtime_info = get_unique_ptr(sess_kv['second']).dereference()  # pylint: disable=undefined-variable
-            session = session_runtime_info['session']
-            # TODO: Add a custom pretty printer for LogicalSessionId.
-            lsid_str = str(session['_sessionId']['_id'])
+        for session_kv in session_kv_pairs:
+            # The Session objects are stored inside the SessionRuntimeInfo object.
+            session_runtime_info = get_unique_ptr(session_kv['second']).dereference()  # pylint: disable=undefined-variable
+            parent_session = session_runtime_info['parentSession']
+            child_sessions = absl_get_nodes(session_runtime_info['childSessions'])  # pylint: disable=undefined-variable
+            lsid = str(parent_session['_sessionId']['_id'])
 
             # If we are only interested in a specific session, then we print out the entire Session
-            # object, to aid more detailed debugging.
-            if lsid_str == lsid_to_find:
-                print("SessionId", "=", lsid_str)
-                print(session)
+            # objects, to aid more detailed debugging.
+            if lsid == lsid_to_find:
+                self.dump_session_runtime_info(session_runtime_info)
+                print(parent_session)
+                for child_session_kv in child_sessions:
+                    child_session = child_session_kv['second']
+                    print(child_session)
                 # Terminate if this is the only session we care about.
                 break
 
             # Only print info for the necessary sessions.
-            if lsid_str not in lsids_to_print:
+            if lsid not in lsids_to_print:
                 continue
 
-            # If we are printing multiple sessions, we only print the most interesting fields from
-            # the Session object for the sake of efficiency. We print the session id string first so
-            # the session is easily identifiable.
-            print("Session (" + str(session.address) + "):")
-            print("SessionId", "=", lsid_str)
-            session_fields_to_print = ['_checkoutOpCtx', '_killsRequested']
-            for field in session_fields_to_print:
+            # If we are printing multiple sessions, we only print the most interesting fields for
+            # each Session object for the sake of efficiency.
+            self.dump_session_runtime_info(session_runtime_info)
+            self.dump_session(parent_session)
+            for child_session_kv in child_sessions:
+                child_session = child_session_kv['second']
+                self.dump_session(child_session)
+
+    @staticmethod
+    def dump_session_runtime_info(session_runtime_info):
+        """Dump the session runtime info."""
+
+        parent_session = session_runtime_info['parentSession']
+        # TODO: Add a custom pretty printer for LogicalSessionId.
+        lsid = str(parent_session['_sessionId']['_id'])[1:-1]
+        print("SessionId =", lsid)
+        fields_to_print = ['checkoutOpCtx', 'killsRequested']
+        for field in fields_to_print:
+            # Skip fields that aren't found on the object.
+            if field in get_field_names(session_runtime_info):
+                print(field, "=", session_runtime_info[field])
+            else:
+                print("Could not find field '%s' on the SessionRuntimeInfo object." % field)
+        print("")
+
+    @staticmethod
+    def dump_session(session):
+        """Dump the session."""
+
+        print("Session (" + str(session.address) + "):")
+        fields_to_print = ['_sessionId', '_numWaitingToCheckOut']
+        for field in fields_to_print:
+            # Skip fields that aren't found on the object.
+            if field in get_field_names(session):
+                print(field, "=", session[field])
+            else:
+                print("Could not find field '%s' on the SessionRuntimeInfo object." % field)
+
+        # Print the information from a TransactionParticipant if a session has one.
+        txn_part_dec = get_decoration(session, "TransactionParticipant")
+        if txn_part_dec:
+            # Only print the most interesting fields for debugging transactions issues. The
+            # TransactionParticipant class encapsulates internal state in two distinct
+            # structures: a 'PrivateState' type (stored in private field '_p') and an
+            # 'ObservableState' type (stored in private field '_o'). The information we care
+            # about here is all contained inside the 'ObservableState', so we extract fields
+            # from that object. If, in the future, we want to print fields from the
+            # 'PrivateState' object, we can inspect the TransactionParticipant's '_p' field.
+            txn_part = txn_part_dec[1]
+            txn_part_observable_state = txn_part['_o']
+            fields_to_print = ['txnState', 'activeTxnNumberAndRetryCounter']
+            print("TransactionParticipant (" + str(txn_part.address) + "):")
+            for field in fields_to_print:
                 # Skip fields that aren't found on the object.
-                if field in get_field_names(session):
-                    print(field, "=", session[field])
-                else:
-                    print("Could not find field '%s' on the Session object." % field)
-
-            # Print the information from a TransactionParticipant if a session has one. Otherwise
-            # we just print the session's id and nothing else.
-            txn_part_dec = get_decoration(session, "TransactionParticipant")
-            if txn_part_dec:
-                # Only print the most interesting fields for debugging transactions issues. The
-                # TransactionParticipant class encapsulates internal state in two distinct
-                # structures: a 'PrivateState' type (stored in private field '_p') and an
-                # 'ObservableState' type (stored in private field '_o'). The information we care
-                # about here is all contained inside the 'ObservableState', so we extract fields
-                # from that object. If, in the future, we want to print fields from the
-                # 'PrivateState' object, we can inspect the TransactionParticipant's '_p' field.
-                txn_part = txn_part_dec[1]
-                txn_part_observable_state = txn_part['_o']
-                fields_to_print = ['txnState', 'activeTxnNumber']
-                print("TransactionParticipant (" + str(txn_part.address) + "):")
-                for field in fields_to_print:
-                    # Skip fields that aren't found on the object.
-                    if field in get_field_names(txn_part_observable_state):
-                        print(field, "=", txn_part_observable_state[field])
-                    else:
-                        print("Could not find field '%s' on the TransactionParticipant" % field)
-
-                # The 'txnResourceStash' field is a boost::optional so we unpack it manually if it
-                # is non-empty. We are only interested in its Locker object for now. TODO: Load the
-                # boost pretty printers so the object will be printed clearly by default, without
-                # the need for special unpacking.
-                val = get_boost_optional(txn_part_observable_state['txnResourceStash'])
-                if val:
-                    locker_addr = get_unique_ptr(val["_locker"])  # pylint: disable=undefined-variable
-                    locker_obj = locker_addr.dereference().cast(
-                        gdb.lookup_type("mongo::LockerImpl"))
-                    print('txnResourceStash._locker', "@", locker_addr)
-                    print("txnResourceStash._locker._id", "=", locker_obj["_id"])
+                if field in get_field_names(txn_part_observable_state):
+                    print(field, "=", txn_part_observable_state[field])
                 else:
-                    print('txnResourceStash', "=", None)
-            # Separate sessions by a newline.
-            print("")
+                    print("Could not find field '%s' on the TransactionParticipant" % field)
+
+            # The 'txnResourceStash' field is a boost::optional so we unpack it manually if it
+            # is non-empty. We are only interested in its Locker object for now. TODO: Load the
+            # boost pretty printers so the object will be printed clearly by default, without
+            # the need for special unpacking.
+            val = get_boost_optional(txn_part_observable_state['txnResourceStash'])
+            if val:
+                locker_addr = get_unique_ptr(val["_locker"])  # pylint: disable=undefined-variable
+                locker_obj = locker_addr.dereference().cast(gdb.lookup_type("mongo::LockerImpl"))
+                print('txnResourceStash._locker', "@", locker_addr)
+                print("txnResourceStash._locker._id", "=", locker_obj["_id"])
+            else:
+                print('txnResourceStash', "=", None)
+        print("")
 
 
 # Register command
@@ -536,39 +561,51 @@ class MongoDBDumpRecoveryUnits(gdb.Command):
 
         # Dump stashed recovery unit info for each session in a mongod process
         for session_kv in get_session_kv_pairs():
-            session_runtime_info = get_unique_ptr(session_kv["second"]).dereference()  # pylint: disable=undefined-variable
-            session = session_runtime_info["session"]
+            # The Session objects are stored inside the SessionRuntimeInfo object.
+            session_runtime_info = get_unique_ptr(session_kv['second']).dereference()  # pylint: disable=undefined-variable
+            parent_session = session_runtime_info['parentSession']
+            child_sessions = absl_get_nodes(session_runtime_info['childSessions'])  # pylint: disable=undefined-variable
 
-            # Prepare structured output doc
-            session_lsid = str(session["_sessionId"]["_id"])[1:-1]
-            txn_participant_dec = get_decoration(session, "TransactionParticipant")
-            output_doc = {"session": session_lsid, "txnResourceStash": "0x0"}
-
-            recovery_unit_handle = None
-            recovery_unit = None
-            if txn_participant_dec:
-                txn_participant_observable_state = txn_participant_dec[1]["_o"]
-                txn_resource_stash = get_boost_optional(
-                    txn_participant_observable_state["txnResourceStash"])
-
-                if txn_resource_stash:
-                    output_doc["txnResourceStash"] = str(txn_resource_stash.address)
-                    recovery_unit_handle = get_unique_ptr(txn_resource_stash["_recoveryUnit"])  # pylint: disable=undefined-variable
-                    # By default, cast the recovery unit as "mongo::WiredTigerRecoveryUnit"
-                    recovery_unit = recovery_unit_handle.dereference().cast(
-                        gdb.lookup_type(recovery_unit_impl_type))
-
-            output_doc["recoveryUnit"] = hex(recovery_unit_handle) if recovery_unit else "0x0"
-            wt_session = get_wt_session(recovery_unit, recovery_unit_impl_type)
-            if wt_session:
-                output_doc["WT_SESSION"] = hex(wt_session)
-            print(json.dumps(output_doc))
-            if recovery_unit:
-                print(recovery_unit)
+            MongoDBDumpRecoveryUnits.dump_session(parent_session, recovery_unit_impl_type)
+            for child_session_kv in child_sessions:
+                child_session = child_session_kv['second']
+                MongoDBDumpRecoveryUnits.dump_session(child_session, recovery_unit_impl_type)
 
         if enabled_at_start:
             gdb.execute("set print static-members on")
 
+    @staticmethod
+    def dump_session(session, recovery_unit_impl_type):
+        """Dump the session."""
+
+        # Prepare structured output doc
+        lsid = session["_sessionId"]
+        output_doc = {"session": str(lsid["_id"])[1:-1], "txnResourceStash": "0x0"}
+        txn_participant_dec = get_decoration(session, "TransactionParticipant")
+        recovery_unit_handle = None
+        recovery_unit = None
+
+        if txn_participant_dec:
+            txn_participant_observable_state = txn_participant_dec[1]["_o"]
+            txn_resource_stash = get_boost_optional(
+                txn_participant_observable_state["txnResourceStash"])
+            if txn_resource_stash:
+                output_doc["txnResourceStash"] = str(txn_resource_stash.address)
+                recovery_unit_handle = get_unique_ptr(txn_resource_stash["_recoveryUnit"])  # pylint: disable=undefined-variable
+                # By default, cast the recovery unit as "mongo::WiredTigerRecoveryUnit"
+                recovery_unit = recovery_unit_handle.dereference().cast(
+                    gdb.lookup_type(recovery_unit_impl_type))
+
+        output_doc["recoveryUnit"] = hex(recovery_unit_handle) if recovery_unit else "0x0"
+        wt_session = get_wt_session(recovery_unit, recovery_unit_impl_type)
+        if wt_session:
+            output_doc["WT_SESSION"] = hex(wt_session)
+
+        print(json.dumps(output_doc))
+        print(lsid)
+        if recovery_unit:
+            print(recovery_unit)
+
 
 # Register command
 MongoDBDumpRecoveryUnits()