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rotor is event loop friendly C++ actor micro framework. Travis Build status codecov Codacy Badge license


  • minimalistic loop agnostic core
  • erlang-like hierarchical supervisors, see
  • various event loops supported (wx, boost-asio, ev) or planned (uv, gtk, etc.)
  • asynchornous message passing interface
  • request-response messaging with cancellation capabilities, see
  • MPMC (multiple producers mupltiple consumers) messaging, aka pub-sub
  • cross-platform (windows, macosx, linux)
  • inspired by The Reactive Manifesto and sobjectizer




Please read tutorial, design principles and manual here


0.14 (20-Feb-2021)

  • the dedicated article with highlights: en and ru
  • [improvement] actor identity has been introduced. It can be configured or generated via address_maker plugin
  • [improvement] actor::do_shutdown() - optionally takes shutdown reason
  • [improvement/breaking] instead of using std::error_code the extended_error class is used. It wraps std::error_code, provides string context and pointer to the next extended_error cause. This greatly simplfies error tracking of errors. Every response now contains ee field instead of ec.
  • [improvement] actor has shutdown reason (in form of extended_error pointer)
  • [improvement] delivery plugin in debug mode it dumps shutdown reason in shutdown trigger messages
  • [improvement] actor identity has on_unlink method to get it know, when it has been unlinked from server actor
  • [improvement] add resources plugin for supervisor
  • [breaking] all responses now have extended_error pointer instread of std::error_code
  • [breaking] shutdown_request_t and shutdown_trigger_t messages how have shutdown reason (in form of extended_error pointer)
  • [bugfix] link_client_plugin_t do not invoke custom callback, before erasing request in case of failure
  • [bugfix] child_manager_plugin_t reactivate self if a child was created from other plugin.
  • [bugfix] registy actor incorrectly resolves postponed requests to wrong addresses

0.13 (26-Dec-2020)

  • [improvement] delivery plugin in debug mode dumps discarded messages
  • [breaking] state_response_t has been removed
  • [bugfix] allow to acquire & release resources in via resources_plugin_t, during other plugin configuration
  • [bugfix] foreigners_support_plugin_t did not deactivated self properly, caused assertion fail on supervisor shutdown, when there was foreign subscriptions
  • [bugfix] link_client_plugin_t did not notified linked server-actors, if its actor is going to shutdown; now server-actors are requested to unlink
  • [bugfix] starter_plugin_t sometimes crashed when subscription confirmation message arrives when actor is in non-initializing phase (i.e. shutting down)
  • [bugfix] root supervisor is not shutdown properly when it is linked as "server"

0.12 (08-Dec-2020)

  • [improvement] added std::thread backend (supervisor)
  • [bugfix] active timers, if any, are cancelled upon actor shutdown finish
  • [bugfix] supervisor shutdown message is lost in rare cases right after child actor start
  • [example] examples/thread/sha512.cpp (new)
  • [documentation] updated Event loops & platforms
  • [documentation] updated Patterns with Blocking I/O multiplexing
  • [deprecated] state_response_t, state_request_t will be removed in v0.13

0.11 (20-Nov-2020)

  • [improvement] when supervisor shuts self down due to child init failure, the supervisor init error code is "failure escalation"
  • [documentation] updated Advanced examples,
  • [bugfix] when actor shuts self down all its timers are properly cancelled
  • [bugfix] in rare case supervisor starts, event if child failed to init
  • [bugfix] asio: more correct timers cancellation implementation
  • [bugfix] ev: more correct shutdown (avoid memory leaks in rare cases)

0.10 (09-Nov-2020)

  • [improvement/breaking] Generic timers interface
  • [improvement] Request cancellation support
  • [improvement] added make_response methods when message should be created, but send later delayed
  • [improvement] more debug information in message delivery plugin
  • [documentation] Integration with event loops
  • [documentation] Requests cancellation and timers are demonstrated in the Advanced Examples section
  • [example] examples/boost-asio/ping-pong-timer.cpp (new)
  • [example] examples/boost-asio/beast-scrapper.cpp (updated)
  • [bugfix] avoid double configuration of a plugin in certain cases when interacting with resources plugin
  • [bugfix] more correct cmake installation (thanks to Jorge López Tello, @LtdJorge)

0.09 (03-Oct-2020)

  • the dedicated article with highlights: en and ru
  • [improvement] rewritten whole documentation
  • [improvement/breaking] plugin system where introduced for actors instead of behaviors
  • [improvement] actor_config_t was introduced, which now holds pointer to supervisor, init and shutdown timeouts
  • [improvement] builder pattern was introduced to simplify actors construction
  • [breaking] supervisor_config_t was changed (inherited from actor_config_t)
  • [breaking] actor_base_t and supervisor_t constructors has changed - now appropriate config is taken as single parameter. All descendant classes should be changed
  • [breaking] if a custom config type is used for actors/supervisors, they should define config_t inside the class, and templated config_builder_t.
  • [breaking] supervisor in actor is now accessibe via pointer instead of refence
  • [bugfix] supervisor_ev_t not always correctly released EV-resources, which lead to leak
  • [bugfix] actor_base_t can be shutted down properly even if it did not started yet

0.08 (12-Apr-2020)

  • [bugfix] message's arguments are more correctly forwarded
  • [bugfix] actor's arguments are more correctly forwarded in actor's creation inrotor::supervisor_t and rotor::asio::supervisor_asio_t
  • [bugfix] rotor::asio::forwarder_t now more correctly dispatches boost::asio events to actor methods; e.g. it works correctly now with async_accept method of socket_acceptor

0.07 (02-Apr-2020)

  • [improvement] more modern cmake usage

0.06 (09-Nov-2019)

  • [improvement] registy actor was added to allow via name/address runtime matching do services discovery
  • [improvement, breaking] minor changes in supervisor behavior: now it is considered initialied when all its children confirmed initialization
  • [improvement] supervisor_policy_t was introduced to control supervisor behavior on a child-actor startup failure
  • [example] examples/ev/pong-registry.cpp how to use registry
  • [doc] patterns/Registry was added

0.05 (22-Sep-2019)

  • [improvement] response can be inherited from rotor::arc_base, to allow forwarding requests without copying it (i.e. just intrusive pointer is created)
  • [example] examples/boost-asio/beast-scrapper.cpp has been added; it demonstrates an app with pool of actor workers with request-response forwarding

0.04 (14-Sep-2019)

  • [improvement] the request-response approach is integrated to support basic reliable messaging: response notification failure will be delivered, if the expected response will not arrive in-time
  • [improvement] lambda subscribiers are supported
  • [improvement] actor behavior has been introduced to offload actor's interface
  • [breaking] supervisor is constructed with help of supervisor_config_t, which contains shutdown timeout value
  • [breaking] supervisor does not spawns timeout timer for overall shutdown procedure, instead per-child timers are spawned. The root supervisor the same way monitors child-supervisor shut down
  • [breaking] supervisor create_actor method now takes child max init time value. If it does not confirm, the child actor will be asked for shut down.
  • [breaking] shutdown request sent to an child actor now timeout-tracked by supervisor. The message type has changed to message::shutdown_request_t
  • [breaking] init request sent to an child actor now timeout-tracked by supervisor. The message type has changed to message::init_request_t
  • [breaking] actor's state request message type now message::state_request_t, which follows the generic request/response pattern. The response type is now message::state_response_t.
  • [breaking] {asio, ev, ws} supervisor configs are renamed to have corresponding suffix.

0.03 (25-Aug-2019)

  • [improvement] locality notion was introduced, which led to possibilty to build superving trees, see blog-cpp-supervisors
  • [breaking] the outbound field in rotor::supervisor_t was renamed just to queue
  • [breaking] rotor::address_t now contains const void* locality
  • [breaking] rotor::asio::supervisor_config_t now contains std::shared_ptr to strand, instead of creating private strand for each supervisor
  • [bugfix] redundant do_start() method in rotor::supervisor_t was removed, since supervisor now is able to start self after compliting initialization.
  • [bugfix] rotor::supervisor_t sends initialize_actor_t to self to advance own state to INITIALIZED via common actor mechanism, instead of changeing state directly on early initialization phase (do_initialize)
  • [bugfix] rotor::asio::forwarder_t now more correctly dispatches boost::asio events to actor methods
  • [bugfix] rotor::ev::supervisor_ev_t properly handles refcounter

0.02 (04-Aug-2019)

  • Added libev support

0.01 (24-Jul-2019)

Initial version

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