%% time_travel_debugging.erl %% Time-travel debugging and process replay system %% Advanced debugging with process history recording and deterministic replay -module(time_travel_debugging). -behaviour(gen_server). -export([ start_link/0, start_recording/2, stop_recording/1, create_checkpoint/2, replay_from_checkpoint/3, time_travel_to_point/3, record_process_tree/2, replay_process_tree/3, debug_message_flow/3, causality_analysis/2, temporal_breakpoint/3, reverse_execution/3, differential_debugging/4, distributed_replay/3, quantum_state_debugging/2 ]). -export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]). -define(RECORDING_REGISTRY, process_recording_registry). -define(CHECKPOINT_STORAGE, checkpoint_storage). -define(MESSAGE_HISTORY, message_flow_history). -define(TEMPORAL_INDEX, temporal_event_index). -record(state, { active_recordings = #{}, checkpoints = #{}, replay_sessions = #{}, temporal_index, causality_analyzer, reverse_executor, distributed_coordinator, quantum_debugger, recording_overhead_monitor }). -record(process_recording, { target_pid, recording_id, start_time, end_time, message_history = [], state_snapshots = [], code_versions = [], memory_states = [], cpu_usage = [], network_events = [], file_operations = [], system_calls = [], garbage_collections = [], scheduling_events = [], link_events = [], monitor_events = [], trap_exits = [], metadata = #{} }). -record(checkpoint, { checkpoint_id, timestamp, process_states = #{}, message_queues = #{}, system_state, memory_snapshot, code_versions = #{}, network_topology, distributed_state = #{}, quantum_states = #{}, causality_graph, environmental_context = #{} }). -record(replay_session, { session_id, target_processes = [], replay_mode, % deterministic, probabilistic, exploratory start_checkpoint, current_position, replay_speed = 1.0, breakpoints = [], watchpoints = [], step_mode = false, causality_mode = false, distributed_mode = false, debug_observers = [], replay_statistics = #{} }). -record(temporal_event, { event_id, timestamp, event_type, % message, state_change, code_load, gc, schedule, etc. process_id, event_data, causality_links = [], quantum_entanglements = [], distributed_context = #{}, metadata = #{} }). -record(causality_link, { source_event, target_event, link_type, % happens_before, concurrent, causal_dependency strength, % 0.0 to 1.0 temporal_distance, quantum_correlation = undefined }). %% Public API start_link() -> gen_server:start_link({local, ?MODULE}, ?MODULE, [], []). %% Start recording process execution history start_recording(ProcessId, RecordingOptions) -> gen_server:call(?MODULE, {start_recording, ProcessId, RecordingOptions}). %% Stop recording and save history stop_recording(RecordingId) -> gen_server:call(?MODULE, {stop_recording, RecordingId}). %% Create system checkpoint for later replay create_checkpoint(CheckpointId, CheckpointOptions) -> gen_server:call(?MODULE, {create_checkpoint, CheckpointId, CheckpointOptions}, 30000). %% Replay execution from a specific checkpoint replay_from_checkpoint(CheckpointId, ReplayOptions, ObserverPid) -> gen_server:call(?MODULE, {replay_from_checkpoint, CheckpointId, ReplayOptions, ObserverPid}, 60000). %% Time travel to a specific point in execution history time_travel_to_point(ProcessId, Timestamp, TravelOptions) -> gen_server:call(?MODULE, {time_travel, ProcessId, Timestamp, TravelOptions}). %% Record entire process tree including supervision hierarchy record_process_tree(RootPid, TreeOptions) -> gen_server:call(?MODULE, {record_tree, RootPid, TreeOptions}). %% Replay entire process tree with coordination replay_process_tree(TreeCheckpoint, ReplayStrategy, Coordination) -> gen_server:call(?MODULE, {replay_tree, TreeCheckpoint, ReplayStrategy, Coordination}). %% Debug message flow between processes debug_message_flow(SourcePid, TargetPid, FlowOptions) -> gen_server:call(?MODULE, {debug_flow, SourcePid, TargetPid, FlowOptions}). %% Analyze causality relationships in recorded execution causality_analysis(RecordingId, AnalysisOptions) -> gen_server:call(?MODULE, {causality_analysis, RecordingId, AnalysisOptions}). %% Set temporal breakpoint at specific execution point temporal_breakpoint(ProcessId, Condition, BreakpointOptions) -> gen_server:call(?MODULE, {temporal_breakpoint, ProcessId, Condition, BreakpointOptions}). %% Execute in reverse (experimental) reverse_execution(ProcessId, ReverseSteps, ReverseOptions) -> gen_server:call(?MODULE, {reverse_execution, ProcessId, ReverseSteps, ReverseOptions}). %% Compare two execution traces for differential debugging differential_debugging(Trace1, Trace2, ComparisonCriteria, AnalysisDepth) -> gen_server:call(?MODULE, {differential_debug, Trace1, Trace2, ComparisonCriteria, AnalysisDepth}). %% Coordinate replay across distributed nodes distributed_replay(DistributedCheckpoint, NodeCoordination, SyncStrategy) -> gen_server:call(?MODULE, {distributed_replay, DistributedCheckpoint, NodeCoordination, SyncStrategy}). %% Debug quantum-entangled process states quantum_state_debugging(QuantumProcesses, QuantumOptions) -> gen_server:call(?MODULE, {quantum_debug, QuantumProcesses, QuantumOptions}). %% Gen_server callbacks init([]) -> % Create ETS tables for temporal debugging ets:new(?RECORDING_REGISTRY, [named_table, public, {keypos, #process_recording.recording_id}]), ets:new(?CHECKPOINT_STORAGE, [named_table, public, {keypos, #checkpoint.checkpoint_id}]), ets:new(?MESSAGE_HISTORY, [named_table, public, ordered_set]), ets:new(?TEMPORAL_INDEX, [named_table, public, ordered_set]), % Start supporting processes TemporalIndex = spawn_link(fun() -> temporal_indexer_loop(#{}) end), CausalityAnalyzer = spawn_link(fun() -> causality_analyzer_loop(#{}) end), ReverseExecutor = spawn_link(fun() -> reverse_executor_loop(#{}) end), DistributedCoordinator = spawn_link(fun() -> distributed_coordinator_loop(#{}) end), QuantumDebugger = spawn_link(fun() -> quantum_debugger_loop(#{}) end), OverheadMonitor = spawn_link(fun() -> recording_overhead_monitor_loop(#{}) end), {ok, #state{ temporal_index = TemporalIndex, causality_analyzer = CausalityAnalyzer, reverse_executor = ReverseExecutor, distributed_coordinator = DistributedCoordinator, quantum_debugger = QuantumDebugger, recording_overhead_monitor = OverheadMonitor }}. handle_call({start_recording, ProcessId, Options}, _From, State) -> Result = initiate_process_recording(ProcessId, Options, State), NewState = update_active_recordings(ProcessId, Result, State), {reply, Result, NewState}; handle_call({stop_recording, RecordingId}, _From, State) -> Result = finalize_process_recording(RecordingId, State), NewState = remove_active_recording(RecordingId, State), {reply, Result, NewState}; handle_call({create_checkpoint, CheckpointId, Options}, _From, State) -> Result = create_system_checkpoint(CheckpointId, Options, State), NewState = store_checkpoint(CheckpointId, Result, State), {reply, Result, NewState}; handle_call({replay_from_checkpoint, CheckpointId, Options, Observer}, _From, State) -> Result = execute_checkpoint_replay(CheckpointId, Options, Observer, State), NewState = register_replay_session(Result, State), {reply, Result, NewState}; handle_call({time_travel, ProcessId, Timestamp, Options}, _From, State) -> Result = execute_time_travel(ProcessId, Timestamp, Options, State), {reply, Result, State}; handle_call({record_tree, RootPid, Options}, _From, State) -> Result = initiate_tree_recording(RootPid, Options, State), {reply, Result, State}; handle_call({replay_tree, Checkpoint, Strategy, Coordination}, _From, State) -> Result = execute_tree_replay(Checkpoint, Strategy, Coordination, State), {reply, Result, State}; handle_call({debug_flow, SourcePid, TargetPid, Options}, _From, State) -> Result = analyze_message_flow(SourcePid, TargetPid, Options, State), {reply, Result, State}; handle_call({causality_analysis, RecordingId, Options}, _From, State) -> Result = perform_causality_analysis(RecordingId, Options, State), {reply, Result, State}; handle_call({temporal_breakpoint, ProcessId, Condition, Options}, _From, State) -> Result = set_temporal_breakpoint(ProcessId, Condition, Options, State), {reply, Result, State}; handle_call({reverse_execution, ProcessId, Steps, Options}, _From, State) -> Result = execute_reverse_execution(ProcessId, Steps, Options, State), {reply, Result, State}; handle_call({differential_debug, Trace1, Trace2, Criteria, Depth}, _From, State) -> Result = perform_differential_debugging(Trace1, Trace2, Criteria, Depth, State), {reply, Result, State}; handle_call({distributed_replay, Checkpoint, Coordination, Strategy}, _From, State) -> Result = coordinate_distributed_replay(Checkpoint, Coordination, Strategy, State), {reply, Result, State}; handle_call({quantum_debug, Processes, Options}, _From, State) -> Result = debug_quantum_states(Processes, Options, State), {reply, Result, State}; handle_call(_Request, _From, State) -> {reply, {error, unknown_request}, State}. handle_cast({record_event, Event}, State) -> record_temporal_event(Event), {noreply, State}; handle_cast({replay_step, SessionId, Step}, State) -> execute_replay_step(SessionId, Step), {noreply, State}; handle_cast({breakpoint_hit, ProcessId, BreakpointData}, State) -> handle_temporal_breakpoint_hit(ProcessId, BreakpointData), {noreply, State}; handle_cast({causality_update, CausalityData}, State) -> update_causality_graph(CausalityData), {noreply, State}; handle_cast(_Msg, State) -> {noreply, State}. handle_info({recording_event, ProcessId, EventData}, State) -> process_recording_event(ProcessId, EventData), {noreply, State}; handle_info({replay_timer, SessionId}, State) -> advance_replay_session(SessionId), {noreply, State}; handle_info({checkpoint_gc, CheckpointId}, State) -> garbage_collect_old_checkpoint(CheckpointId), {noreply, State}; handle_info({distributed_sync, SyncData}, State) -> handle_distributed_synchronization(SyncData), {noreply, State}; handle_info(_Info, State) -> {noreply, State}. terminate(_Reason, _State) -> ok. code_change(_OldVsn, State, _Extra) -> {ok, State}. %% Core Implementation initiate_process_recording(ProcessId, Options, State) -> try % Phase 1: Validate target process case is_process_alive(ProcessId) of true -> % Phase 2: Create recording configuration RecordingId = generate_recording_id(), RecordingConfig = create_recording_config(ProcessId, Options), % Phase 3: Install recording probes ProbeResult = install_recording_probes(ProcessId, RecordingConfig), case ProbeResult of {ok, Probes} -> % Phase 4: Start temporal indexing start_temporal_indexing(RecordingId, ProcessId), % Phase 5: Initialize recording state Recording = #process_recording{ target_pid = ProcessId, recording_id = RecordingId, start_time = erlang:system_time(microsecond), metadata = maps:merge(Options, #{probes => Probes}) }, % Phase 6: Register recording ets:insert(?RECORDING_REGISTRY, Recording), {ok, #{ recording_id => RecordingId, target_process => ProcessId, probes_installed => length(Probes), recording_overhead => estimate_recording_overhead(Options) }}; {error, ProbeError} -> {error, {probe_installation_failed, ProbeError}} end; false -> {error, {process_not_alive, ProcessId}} end catch E:R:S -> {error, {recording_initialization_failed, E, R, S}} end. create_system_checkpoint(CheckpointId, Options, State) -> try % Phase 1: Pause all recorded processes (optional) PauseResult = maybe_pause_processes(Options), % Phase 2: Capture process states ProcessStates = capture_all_process_states(), % Phase 3: Capture message queues MessageQueues = capture_all_message_queues(), % Phase 4: Capture system state SystemState = capture_system_state(), % Phase 5: Capture memory snapshot MemorySnapshot = capture_memory_snapshot(Options), % Phase 6: Capture code versions CodeVersions = capture_code_versions(), % Phase 7: Capture network topology NetworkTopology = capture_network_topology(), % Phase 8: Capture distributed state DistributedState = capture_distributed_state(), % Phase 9: Capture quantum states (if applicable) QuantumStates = capture_quantum_states(), % Phase 10: Build causality graph CausalityGraph = build_current_causality_graph(), % Phase 11: Create checkpoint record Checkpoint = #checkpoint{ checkpoint_id = CheckpointId, timestamp = erlang:system_time(microsecond), process_states = ProcessStates, message_queues = MessageQueues, system_state = SystemState, memory_snapshot = MemorySnapshot, code_versions = CodeVersions, network_topology = NetworkTopology, distributed_state = DistributedState, quantum_states = QuantumStates, causality_graph = CausalityGraph, environmental_context = capture_environmental_context() }, % Phase 12: Resume processes if paused maybe_resume_processes(PauseResult), % Phase 13: Store checkpoint ets:insert(?CHECKPOINT_STORAGE, Checkpoint), {ok, #{ checkpoint_id => CheckpointId, timestamp => Checkpoint#checkpoint.timestamp, processes_captured => maps:size(ProcessStates), memory_size => calculate_memory_size(MemorySnapshot), distributed_nodes => maps:size(DistributedState), causality_edges => count_causality_edges(CausalityGraph) }} catch E:R:S -> {error, {checkpoint_creation_failed, E, R, S}} end. execute_checkpoint_replay(CheckpointId, Options, ObserverPid, State) -> case ets:lookup(?CHECKPOINT_STORAGE, CheckpointId) of [Checkpoint] -> try % Phase 1: Create replay session SessionId = generate_session_id(), ReplaySession = create_replay_session(SessionId, Checkpoint, Options), % Phase 2: Initialize replay environment ReplayEnv = initialize_replay_environment(Checkpoint, Options), % Phase 3: Restore system state restore_system_state(Checkpoint#checkpoint.system_state), % Phase 4: Restore process states RestoreResult = restore_process_states(Checkpoint#checkpoint.process_states), % Phase 5: Restore message queues restore_message_queues(Checkpoint#checkpoint.message_queues), % Phase 6: Restore code versions restore_code_versions(Checkpoint#checkpoint.code_versions), % Phase 7: Restore network topology restore_network_topology(Checkpoint#checkpoint.network_topology), % Phase 8: Setup replay orchestration OrchestrationResult = setup_replay_orchestration(ReplaySession, ObserverPid), % Phase 9: Start replay execution ReplayResult = start_replay_execution(ReplaySession, OrchestrationResult), {ok, #{ session_id => SessionId, checkpoint_restored => CheckpointId, processes_restored => length(RestoreResult), replay_environment => ReplayEnv, orchestration => OrchestrationResult, execution_started => ReplayResult }} catch E:R:S -> {error, {replay_execution_failed, E, R, S}} end; [] -> {error, {checkpoint_not_found, CheckpointId}} end. execute_time_travel(ProcessId, Timestamp, Options, State) -> % Time travel to specific execution point try % Phase 1: Find recording containing the timestamp RecordingResult = find_recording_for_time_travel(ProcessId, Timestamp), case RecordingResult of {ok, Recording} -> % Phase 2: Locate exact temporal position TemporalPosition = locate_temporal_position(Recording, Timestamp), % Phase 3: Create time travel checkpoint TravelCheckpoint = create_time_travel_checkpoint(Recording, TemporalPosition), % Phase 4: Restore to temporal position RestoreResult = restore_to_temporal_position(TravelCheckpoint, Options), % Phase 5: Setup time travel session TravelSession = setup_time_travel_session(ProcessId, TemporalPosition, Options), {ok, #{ process_id => ProcessId, target_timestamp => Timestamp, actual_position => TemporalPosition, travel_checkpoint => TravelCheckpoint, restore_result => RestoreResult, travel_session => TravelSession }}; {error, RecordingError} -> {error, {recording_not_found, RecordingError}} end catch E:R:S -> {error, {time_travel_failed, E, R, S}} end. perform_causality_analysis(RecordingId, Options, State) -> case ets:lookup(?RECORDING_REGISTRY, RecordingId) of [Recording] -> try % Phase 1: Extract temporal events TemporalEvents = extract_temporal_events(Recording), % Phase 2: Build causality graph CausalityGraph = build_causality_graph(TemporalEvents, Options), % Phase 3: Analyze causal relationships CausalAnalysis = analyze_causal_relationships(CausalityGraph), % Phase 4: Detect causality violations ViolationAnalysis = detect_causality_violations(CausalityGraph), % Phase 5: Identify critical paths CriticalPaths = identify_critical_causal_paths(CausalityGraph), % Phase 6: Generate causality insights CausalityInsights = generate_causality_insights(CausalAnalysis, Options), {ok, #{ recording_id => RecordingId, temporal_events => length(TemporalEvents), causality_graph => CausalityGraph, causal_analysis => CausalAnalysis, violation_analysis => ViolationAnalysis, critical_paths => CriticalPaths, insights => CausalityInsights }} catch E:R:S -> {error, {causality_analysis_failed, E, R, S}} end; [] -> {error, {recording_not_found, RecordingId}} end. %% Supporting Process Loops temporal_indexer_loop(State) -> receive {index_event, Event} -> IndexedEvent = create_temporal_index_entry(Event), ets:insert(?TEMPORAL_INDEX, IndexedEvent), temporal_indexer_loop(State); {query_temporal_range, StartTime, EndTime, From} -> Events = query_temporal_events(StartTime, EndTime), From ! {temporal_events, Events}, temporal_indexer_loop(State); stop -> ok end. causality_analyzer_loop(State) -> receive {analyze_causality, Events, Options, From} -> CausalityResult = perform_causality_computation(Events, Options), From ! {causality_result, CausalityResult}, causality_analyzer_loop(State); {update_causality_model, ModelUpdate} -> NewState = update_causality_analysis_model(ModelUpdate, State), causality_analyzer_loop(NewState); stop -> ok end. reverse_executor_loop(State) -> receive {reverse_execute, ProcessId, Steps, Options, From} -> ReverseResult = perform_reverse_execution(ProcessId, Steps, Options), From ! {reverse_result, ReverseResult}, reverse_executor_loop(State); {compute_reverse_state, StateData, From} -> ReversedState = compute_reverse_process_state(StateData), From ! {reversed_state, ReversedState}, reverse_executor_loop(State); stop -> ok end. %% Utility Functions generate_recording_id() -> list_to_binary([ "recording_", atom_to_list(node()), "_", integer_to_list(erlang:system_time(microsecond)) ]). generate_session_id() -> list_to_binary([ "session_", atom_to_list(node()), "_", integer_to_list(erlang:system_time(microsecond)) ]). %% Placeholder implementations for complex debugging operations create_recording_config(_ProcessId, _Options) -> recording_config. install_recording_probes(_ProcessId, _Config) -> {ok, [probe1, probe2]}. start_temporal_indexing(_RecordingId, _ProcessId) -> ok. estimate_recording_overhead(_Options) -> 0.05. finalize_process_recording(_RecordingId, _State) -> {ok, finalized}. update_active_recordings(_ProcessId, _Result, State) -> State. remove_active_recording(_RecordingId, State) -> State. store_checkpoint(_CheckpointId, _Result, State) -> State. register_replay_session(_Result, State) -> State. maybe_pause_processes(_Options) -> no_pause. capture_all_process_states() -> #{}. capture_all_message_queues() -> #{}. capture_system_state() -> system_state. capture_memory_snapshot(_Options) -> memory_snapshot. capture_code_versions() -> #{}. capture_network_topology() -> network_topology. capture_distributed_state() -> #{}. capture_quantum_states() -> #{}. build_current_causality_graph() -> causality_graph. capture_environmental_context() -> #{}. maybe_resume_processes(_PauseResult) -> ok. calculate_memory_size(_Snapshot) -> 1024. count_causality_edges(_Graph) -> 42. create_replay_session(_SessionId, _Checkpoint, _Options) -> replay_session. initialize_replay_environment(_Checkpoint, _Options) -> replay_env. restore_system_state(_SystemState) -> ok. restore_process_states(_ProcessStates) -> []. restore_message_queues(_MessageQueues) -> ok. restore_code_versions(_CodeVersions) -> ok. restore_network_topology(_NetworkTopology) -> ok. setup_replay_orchestration(_Session, _Observer) -> orchestration_result. start_replay_execution(_Session, _Orchestration) -> execution_started. find_recording_for_time_travel(_ProcessId, _Timestamp) -> {ok, recording}. locate_temporal_position(_Recording, _Timestamp) -> temporal_position. create_time_travel_checkpoint(_Recording, _Position) -> travel_checkpoint. restore_to_temporal_position(_Checkpoint, _Options) -> restore_result. setup_time_travel_session(_ProcessId, _Position, _Options) -> travel_session. extract_temporal_events(_Recording) -> []. build_causality_graph(_Events, _Options) -> causality_graph. analyze_causal_relationships(_Graph) -> causal_analysis. detect_causality_violations(_Graph) -> violation_analysis. identify_critical_causal_paths(_Graph) -> critical_paths. generate_causality_insights(_Analysis, _Options) -> insights. record_temporal_event(_Event) -> ok. execute_replay_step(_SessionId, _Step) -> ok. handle_temporal_breakpoint_hit(_ProcessId, _Data) -> ok. update_causality_graph(_Data) -> ok. process_recording_event(_ProcessId, _EventData) -> ok. advance_replay_session(_SessionId) -> ok. garbage_collect_old_checkpoint(_CheckpointId) -> ok. handle_distributed_synchronization(_SyncData) -> ok. create_temporal_index_entry(_Event) -> temporal_index_entry. query_temporal_events(_StartTime, _EndTime) -> []. perform_causality_computation(_Events, _Options) -> causality_result. update_causality_analysis_model(_Update, State) -> State. perform_reverse_execution(_ProcessId, _Steps, _Options) -> reverse_result. compute_reverse_process_state(_StateData) -> reversed_state. initiate_tree_recording(_RootPid, _Options, _State) -> {ok, tree_recording}. execute_tree_replay(_Checkpoint, _Strategy, _Coordination, _State) -> {ok, tree_replay}. analyze_message_flow(_SourcePid, _TargetPid, _Options, _State) -> {ok, flow_analysis}. set_temporal_breakpoint(_ProcessId, _Condition, _Options, _State) -> {ok, breakpoint_set}. execute_reverse_execution(_ProcessId, _Steps, _Options, _State) -> {ok, reverse_executed}. perform_differential_debugging(_Trace1, _Trace2, _Criteria, _Depth, _State) -> {ok, diff_result}. coordinate_distributed_replay(_Checkpoint, _Coordination, _Strategy, _State) -> {ok, distributed_replay}. debug_quantum_states(_Processes, _Options, _State) -> {ok, quantum_debug}. distributed_coordinator_loop(State) -> State. quantum_debugger_loop(State) -> State. recording_overhead_monitor_loop(State) -> State.