8 #include <unordered_set>
14 #include "service-listener.h"
15 #include "service-constants.h"
19 * This header defines service_record, a data record maintaining information about a service,
20 * and service_set, a set of interdependent service records. It also defines some associated
21 * types and exceptions.
25 * Services have both a current state and a desired state. The desired state can be
26 * either STARTED or STOPPED. The current state can also be STARTING or STOPPING.
27 * A service can be "pinned" in either the STARTED or STOPPED states to prevent it
28 * from leaving that state until it is unpinned.
30 * The total state is a combination of the two, current and desired:
31 * STOPPED/STOPPED : stopped and will remain stopped
32 * STOPPED/STARTED : stopped (pinned), must be unpinned to start
33 * STARTING/STARTED : starting, but not yet started. Dependencies may also be starting.
34 * STARTING/STOPPED : as above, but the service will be stopped again as soon as it has
36 * STARTED/STARTED : running and will continue running.
37 * STARTED/STOPPED : started (pinned), must be unpinned to stop
38 * STOPPING/STOPPED : stopping and will stop. Dependents may be stopping.
39 * STOPPING/STARTED : as above, but the service will be re-started again once it stops.
41 * A scripted service is in the STARTING/STOPPING states during the script execution.
42 * A process service is in the STOPPING state when it has been signalled to stop, and is
43 * in the STARTING state when waiting for dependencies to start or for the exec() call in
44 * the forked child to complete and return a status.
46 * Acquisition/release:
48 * Each service has a dependent-count ("required_by"). This starts at 0, adds 1 if the
49 * service has explicitly been started (i.e. "start_explicit" is true), and adds 1 for
50 * each dependent service which is not STOPPED (including dependents with a soft dependency).
51 * When required_by transitions to 0, the service is stopped (unless it is pinned). When
52 * require_by transitions from 0, the service is started (unless pinned).
54 * So, in general, the dependent-count determines the desired state (STARTED if the count
55 * is greater than 0, otherwise STOPPED). However, a service can be issued a stop-and-take
56 * down order (via `stop(true)'); this will first stop dependent services, which may restart
57 * and cancel the stop of the former service. Finally, a service can be force-stopped, which
58 * means that its stop process cannot be cancelled (though it may still be put in a desired
59 * state of STARTED, meaning it will start immediately upon stopping).
63 * A service may be "pinned" in either STARTED or STOPPED states (or even both). Once it
64 * reaches a pinned state, a service will not leave that state, though its desired state
65 * may still be set. (Note that pinning prevents, but never causes, state transition).
67 * The priority of the different state deciders is:
70 * - desired state (which is manipulated by require/release operations)
72 * So a forced stop cannot occur until the service is not pinned started, for instance.
74 * Two-phase transition
75 * --------------------
76 * Transition between states occurs in two phases: propagation and execution. In both phases
77 * a linked-list queue is used to keep track of which services need processing; this avoids
78 * recursion (which would be of unknown depth and therefore liable to stack overflow).
80 * In the propagation phase, acquisition/release messages are processed, and desired state may be
81 * altered accordingly. Start and stop requests are also propagated in this phase. The state may
82 * be set to STARTING or STOPPING to reflect the desired state, but will never be set to STARTED
83 * or STOPPED (that happens in the execution phase).
85 * Propagation variables:
86 * prop_acquire: the service has transitioned to an acquired state and must issue an acquire
88 * prop_release: the service has transitioned to a released state and must issue a release on
91 * prop_start: the service should start
92 * prop_stop: the service should stop
94 * Note that "prop_acquire"/"prop_release" form a pair which cannot both be set at the same time
95 * which is enforced via explicit checks. For "prop_start"/"prop_stop" this occurs implicitly.
97 * In the execution phase, actions are taken to achieve the desired state. Actual state may
98 * transition according to the current and desired states. Processes can be sent signals, etc
99 * in order to stop them. A process can restart if it stops, but it does so by raising prop_start
100 * which needs to be processed in a second transition phase. Seeing as starting never causes
101 * another process to stop, the transition-execute-transition cycle always ends at the 2nd
102 * transition stage, at the latest.
105 struct onstart_flags_t {
109 // Not actually "onstart" commands:
110 bool no_sigterm : 1; // do not send SIGTERM
111 bool runs_on_console : 1; // run "in the foreground"
112 bool starts_on_console : 1; // starts in the foreground
113 bool pass_cs_fd : 1; // pass this service a control socket connection via fd
115 onstart_flags_t() noexcept : rw_ready(false), log_ready(false),
116 no_sigterm(false), runs_on_console(false), starts_on_console(false), pass_cs_fd(false)
121 // Exception while loading a service
122 class service_load_exc
125 std::string serviceName;
126 std::string excDescription;
129 service_load_exc(std::string serviceName, std::string &&desc) noexcept
130 : serviceName(serviceName), excDescription(std::move(desc))
135 class service_not_found : public service_load_exc
138 service_not_found(std::string serviceName) noexcept
139 : service_load_exc(serviceName, "Service description not found.")
144 class service_cyclic_dependency : public service_load_exc
147 service_cyclic_dependency(std::string serviceName) noexcept
148 : service_load_exc(serviceName, "Has cyclic dependency.")
153 class service_description_exc : public service_load_exc
156 service_description_exc(std::string serviceName, std::string &&extraInfo) noexcept
157 : service_load_exc(serviceName, std::move(extraInfo))
162 class service_record;
164 class base_process_service;
166 /* Service dependency record */
169 service_record * from;
173 /* Whether the 'from' service is waiting for the 'to' service to start */
175 /* Whether the 'from' service is holding an acquire on the 'to' service */
178 service_dep(service_record * from, service_record * to) noexcept : from(from), to(to), waiting_on(false), holding_acq(false)
181 service_record * getFrom() noexcept
186 service_record * getTo() noexcept
192 // Given a string and a list of pairs of (start,end) indices for each argument in that string,
193 // store a null terminator for the argument. Return a `char *` vector containing the beginning
194 // of each argument and a trailing nullptr. (The returned array is invalidated if the string is later modified).
195 static std::vector<const char *> separate_args(std::string &s, std::list<std::pair<unsigned,unsigned>> &arg_indices)
197 std::vector<const char *> r;
198 r.reserve(arg_indices.size() + 1);
200 // First store nul terminator for each part:
201 for (auto index_pair : arg_indices) {
202 if (index_pair.second < s.length()) {
203 s[index_pair.second] = 0;
207 // Now we can get the C string (c_str) and store offsets into it:
208 const char * cstr = s.c_str();
209 for (auto index_pair : arg_indices) {
210 r.push_back(cstr + index_pair.first);
212 r.push_back(nullptr);
216 class service_child_watcher : public eventloop_t::child_proc_watcher_impl<service_child_watcher>
219 base_process_service * service;
220 rearm status_change(eventloop_t &eloop, pid_t child, int status) noexcept;
222 service_child_watcher(base_process_service * sr) noexcept : service(sr) { }
225 // Watcher for the pipe used to receive exec() failure status errno
226 class exec_status_pipe_watcher : public eventloop_t::fd_watcher_impl<exec_status_pipe_watcher>
229 base_process_service * service;
230 rearm fd_event(eventloop_t &eloop, int fd, int flags) noexcept;
232 exec_status_pipe_watcher(base_process_service * sr) noexcept : service(sr) { }
238 typedef std::string string;
241 service_type record_type; /* ServiceType::DUMMY, PROCESS, SCRIPTED, INTERNAL */
242 service_state_t service_state = service_state_t::STOPPED; /* service_state_t::STOPPED, STARTING, STARTED, STOPPING */
243 service_state_t desired_state = service_state_t::STOPPED; /* service_state_t::STOPPED / STARTED */
245 string program_name; // storage for program/script and arguments
246 std::vector<const char *> exec_arg_parts; // pointer to each argument/part of the program_name, and nullptr
248 string stop_command; // storage for stop program/script and arguments
249 std::vector<const char *> stop_arg_parts; // pointer to each argument/part of the stop_command, and nullptr
253 onstart_flags_t onstart_flags;
255 string logfile; // log file name, empty string specifies /dev/null
257 bool auto_restart : 1; // whether to restart this (process) if it dies unexpectedly
258 bool smooth_recovery : 1; // whether the service process can restart without bringing down service
260 bool pinned_stopped : 1;
261 bool pinned_started : 1;
262 bool waiting_for_deps : 1; // if STARTING, whether we are waiting for dependencies (inc console) to start
263 bool waiting_for_execstat : 1; // if we are waiting for exec status after fork()
264 bool start_explicit : 1; // whether we are are explictly required to be started
266 bool prop_require : 1; // require must be propagated
267 bool prop_release : 1; // release must be propagated
268 bool prop_failure : 1; // failure to start must be propagated
271 bool restarting : 1; // re-starting after unexpected termination
273 int required_by = 0; // number of dependents wanting this service to be started
275 typedef std::list<service_record *> sr_list;
276 typedef sr_list::iterator sr_iter;
278 // list of soft dependencies
279 typedef std::list<service_dep> softdep_list;
281 // list of soft dependents
282 typedef std::list<service_dep *> softdpt_list;
284 sr_list depends_on; // services this one depends on
285 sr_list dependents; // services depending on this one
286 softdep_list soft_deps; // services this one depends on via a soft dependency
287 softdpt_list soft_dpts; // services depending on this one via a soft dependency
289 // unsigned wait_count; /* if we are waiting for dependents/dependencies to
290 // start/stop, this is how many we're waiting for */
292 service_set *services; // the set this service belongs to
294 std::unordered_set<service_listener *> listeners;
297 bool force_stop; // true if the service must actually stop. This is the
298 // case if for example the process dies; the service,
299 // and all its dependencies, MUST be stopped.
301 int term_signal = -1; // signal to use for process termination
303 string socket_path; // path to the socket for socket-activation service
304 int socket_perms; // socket permissions ("mode")
305 uid_t socket_uid = -1; // socket user id or -1
306 gid_t socket_gid = -1; // socket group id or -1
308 // Implementation details
310 pid_t pid = -1; // PID of the process. If state is STARTING or STOPPING,
311 // this is PID of the service script; otherwise it is the
312 // PID of the process itself (process service).
313 int exit_status; // Exit status, if the process has exited (pid == -1).
314 int socket_fd = -1; // For socket-activation services, this is the file
315 // descriptor for the socket.
318 // Data for use by service_set
322 lld_node<service_record> console_queue_node;
324 // Propagation and start/stop queues
325 lls_node<service_record> prop_queue_node;
326 lls_node<service_record> stop_queue_node;
331 void emergency_stop() noexcept;
333 // All dependents have stopped.
334 virtual void all_deps_stopped() noexcept;
336 // Service has actually stopped (includes having all dependents
337 // reaching STOPPED state).
338 void stopped() noexcept;
340 // Service has successfully started
341 void started() noexcept;
343 // Service failed to start (only called when in STARTING state).
344 // dep_failed: whether failure is recorded due to a dependency failing
345 void failed_to_start(bool dep_failed = false) noexcept;
347 void run_child_proc(const char * const *args, const char *logfile, bool on_console, int wpipefd,
350 // A dependency has reached STARTED state
351 void dependencyStarted() noexcept;
353 void allDepsStarted(bool haveConsole = false) noexcept;
355 // Do any post-dependency startup; return false on failure
356 virtual bool start_ps_process() noexcept;
358 // Open the activation socket, return false on failure
359 bool open_socket() noexcept;
361 // Check whether dependencies have started, and optionally ask them to start
362 bool startCheckDependencies(bool do_start) noexcept;
364 // Whether a STARTING service can immediately transition to STOPPED (as opposed to
365 // having to wait for it reach STARTED and then go through STOPPING).
366 virtual bool can_interrupt_start() noexcept
368 return waiting_for_deps;
371 virtual void interrupt_start() noexcept;
373 // Whether a STOPPING service can immediately transition to STARTED.
374 bool can_interrupt_stop() noexcept
376 return waiting_for_deps && ! force_stop;
379 // A dependent has reached STOPPED state
380 void dependentStopped() noexcept;
382 // check if all dependents have stopped
383 bool stopCheckDependents() noexcept;
385 // issue a stop to all dependents, return true if they are all already stopped
386 bool stopDependents() noexcept;
388 void require() noexcept;
389 void release() noexcept;
390 void release_dependencies() noexcept;
392 // Check if service is, fundamentally, stopped.
393 bool is_stopped() noexcept
395 return service_state == service_state_t::STOPPED
396 || (service_state == service_state_t::STARTING && waiting_for_deps);
399 void notifyListeners(service_event event) noexcept
401 for (auto l : listeners) {
402 l->serviceEvent(this, event);
406 // Queue to run on the console. 'acquiredConsole()' will be called when the console is available.
407 // Has no effect if the service has already queued for console.
408 void queue_for_console() noexcept;
410 // Release console (console must be currently held by this service)
411 void release_console() noexcept;
413 bool do_auto_restart() noexcept;
415 // Started state reached
416 bool process_started() noexcept;
420 service_record(service_set *set, string name)
421 : service_state(service_state_t::STOPPED), desired_state(service_state_t::STOPPED),
422 auto_restart(false), smooth_recovery(false),
423 pinned_stopped(false), pinned_started(false), waiting_for_deps(false),
424 waiting_for_execstat(false), start_explicit(false),
425 prop_require(false), prop_release(false), prop_failure(false),
426 prop_start(false), prop_stop(false), restarting(false), force_stop(false)
430 record_type = service_type::DUMMY;
433 service_record(service_set *set, string name, service_type record_type_p,
434 sr_list &&pdepends_on, const sr_list &pdepends_soft)
435 : service_record(set, name)
439 this->record_type = record_type_p;
440 this->depends_on = std::move(pdepends_on);
442 for (sr_iter i = depends_on.begin(); i != depends_on.end(); ++i) {
443 (*i)->dependents.push_back(this);
447 auto b_iter = soft_deps.end();
448 for (auto i = pdepends_soft.begin(); i != pdepends_soft.end(); ++i) {
449 b_iter = soft_deps.emplace(b_iter, this, *i);
450 (*i)->soft_dpts.push_back(&(*b_iter));
455 service_record(service_set *set, string name, service_type record_type_p, string &&command, std::list<std::pair<unsigned,unsigned>> &command_offsets,
456 sr_list &&pdepends_on, const sr_list &pdepends_soft)
457 : service_record(set, name, record_type_p, std::move(pdepends_on), pdepends_soft)
459 program_name = std::move(command);
460 exec_arg_parts = separate_args(program_name, command_offsets);
463 virtual ~service_record() noexcept
467 // begin transition from stopped to started state or vice versa depending on current and desired state
468 void execute_transition() noexcept;
470 void do_propagation() noexcept;
472 // Called on transition of desired state from stopped to started (or unpinned stop)
473 void do_start() noexcept;
475 // Called on transition of desired state from started to stopped (or unpinned start)
476 void do_stop() noexcept;
478 // Console is available.
479 void acquiredConsole() noexcept;
481 // Set the stop command and arguments (may throw std::bad_alloc)
482 void setStopCommand(std::string command, std::list<std::pair<unsigned,unsigned>> &stop_command_offsets)
484 stop_command = command;
485 stop_arg_parts = separate_args(stop_command, stop_command_offsets);
488 // Get the current service state.
489 service_state_t getState() noexcept
491 return service_state;
494 // Get the target (aka desired) state.
495 service_state_t getTargetState() noexcept
497 return desired_state;
500 // Set logfile, should be done before service is started
501 void setLogfile(string logfile)
503 this->logfile = logfile;
506 // Set whether this service should automatically restart when it dies
507 void setAutoRestart(bool auto_restart) noexcept
509 this->auto_restart = auto_restart;
512 void setSmoothRecovery(bool smooth_recovery) noexcept
514 this->smooth_recovery = smooth_recovery;
517 // Set "on start" flags (commands)
518 void setOnstartFlags(onstart_flags_t flags) noexcept
520 this->onstart_flags = flags;
523 // Set an additional signal (other than SIGTERM) to be used to terminate the process
524 void setExtraTerminationSignal(int signo) noexcept
526 this->term_signal = signo;
529 void set_pid_file(string &&pid_file) noexcept
531 this->pid_file = std::move(pid_file);
534 void set_socket_details(string &&socket_path, int socket_perms, uid_t socket_uid, uid_t socket_gid) noexcept
536 this->socket_path = std::move(socket_path);
537 this->socket_perms = socket_perms;
538 this->socket_uid = socket_uid;
539 this->socket_gid = socket_gid;
542 const std::string &getServiceName() const noexcept { return service_name; }
543 service_state_t getState() const noexcept { return service_state; }
545 void start(bool activate = true) noexcept; // start the service
546 void stop(bool bring_down = true) noexcept; // stop the service
548 void forceStop() noexcept; // force-stop this service and all dependents
550 // Pin the service in "started" state (when it reaches the state)
551 void pinStart() noexcept
553 pinned_started = true;
556 // Pin the service in "stopped" state (when it reaches the state)
557 void pinStop() noexcept
559 pinned_stopped = true;
562 // Remove both "started" and "stopped" pins. If the service is currently pinned
563 // in either state but would naturally be in the opposite state, it will immediately
564 // commence starting/stopping.
565 void unpin() noexcept;
567 bool isDummy() noexcept
569 return record_type == service_type::DUMMY;
572 // Add a listener. A listener must only be added once. May throw std::bad_alloc.
573 void addListener(service_listener * listener)
575 listeners.insert(listener);
578 // Remove a listener.
579 void removeListener(service_listener * listener) noexcept
581 listeners.erase(listener);
585 class base_process_service;
587 // A timer for process restarting. Used to ensure a minimum delay between
589 class process_restart_timer : public eventloop_t::timer_impl<process_restart_timer>
592 base_process_service * service;
594 process_restart_timer()
598 rearm timer_expiry(eventloop_t &, int expiry_count);
601 class base_process_service : public service_record
603 friend class service_child_watcher;
604 friend class exec_status_pipe_watcher;
605 friend class process_restart_timer;
609 void do_restart() noexcept;
612 service_child_watcher child_listener;
613 exec_status_pipe_watcher child_status_listener;
614 process_restart_timer restart_timer;
615 timespec last_start_time;
617 // Restart interval time and restart count are used to track the number of automatic restarts
618 // over an interval. Too many restarts over an interval will inhibit further restarts.
619 timespec restart_interval_time;
620 int restart_interval_count;
622 timespec restart_interval;
623 int max_restart_interval_count;
624 timespec restart_delay;
626 bool waiting_restart_timer = false;
628 // Start the process, return true on success
629 virtual bool start_ps_process() noexcept override;
630 bool start_ps_process(const std::vector<const char *> &args, bool on_console) noexcept;
632 // Restart the process (due to start failure or unexpected termination). Restarts will be
634 bool restart_ps_process() noexcept;
636 virtual void all_deps_stopped() noexcept override;
637 virtual void handle_exit_status(int exit_status) noexcept = 0;
639 virtual bool can_interrupt_start() noexcept override
641 return waiting_restart_timer || service_record::can_interrupt_start();
644 virtual void interrupt_start() noexcept override;
647 base_process_service(service_set *sset, string name, service_type record_type_p, string &&command,
648 std::list<std::pair<unsigned,unsigned>> &command_offsets,
649 sr_list &&pdepends_on, const sr_list &pdepends_soft);
651 ~base_process_service() noexcept
655 void set_restart_interval(timespec interval, int max_restarts) noexcept
657 restart_interval = interval;
658 max_restart_interval_count = max_restarts;
661 void set_restart_delay(timespec delay) noexcept
663 restart_delay = delay;
667 class process_service : public base_process_service
669 // called when the process exits. The exit_status is the status value yielded by
670 // the "wait" system call.
671 virtual void handle_exit_status(int exit_status) noexcept override;
674 process_service(service_set *sset, string name, string &&command,
675 std::list<std::pair<unsigned,unsigned>> &command_offsets,
676 sr_list &&pdepends_on, const sr_list &pdepends_soft)
677 : base_process_service(sset, name, service_type::PROCESS, std::move(command), command_offsets,
678 std::move(pdepends_on), pdepends_soft)
682 ~process_service() noexcept
687 class bgproc_service : public base_process_service
689 virtual void handle_exit_status(int exit_status) noexcept override;
691 bool doing_recovery : 1; // if we are currently recovering a BGPROCESS (restarting process, while
692 // holding STARTED service state)
693 bool tracking_child : 1;
695 enum class pid_result_t {
697 FAILED, // failed to read pid or read invalid pid
698 TERMINATED // read pid successfully, but the process already terminated
701 // Read the pid-file, return false on failure
702 pid_result_t read_pid_file(int *exit_status) noexcept;
705 bgproc_service(service_set *sset, string name, string &&command,
706 std::list<std::pair<unsigned,unsigned>> &command_offsets,
707 sr_list &&pdepends_on, const sr_list &pdepends_soft)
708 : base_process_service(sset, name, service_type::BGPROCESS, std::move(command), command_offsets,
709 std::move(pdepends_on), pdepends_soft)
711 doing_recovery = false;
712 tracking_child = false;
715 ~bgproc_service() noexcept
720 class scripted_service : public base_process_service
722 virtual void all_deps_stopped() noexcept override;
723 virtual void handle_exit_status(int exit_status) noexcept override;
726 scripted_service(service_set *sset, string name, string &&command,
727 std::list<std::pair<unsigned,unsigned>> &command_offsets,
728 sr_list &&pdepends_on, const sr_list &pdepends_soft)
729 : base_process_service(sset, name, service_type::SCRIPTED, std::move(command), command_offsets,
730 std::move(pdepends_on), pdepends_soft)
734 ~scripted_service() noexcept
739 inline auto extract_prop_queue(service_record *sr) -> decltype(sr->prop_queue_node) &
741 return sr->prop_queue_node;
744 inline auto extract_stop_queue(service_record *sr) -> decltype(sr->stop_queue_node) &
746 return sr->stop_queue_node;
749 inline auto extract_console_queue(service_record *sr) -> decltype(sr->console_queue_node) &
751 return sr->console_queue_node;
755 * A service_set, as the name suggests, manages a set of services.
757 * Other than the ability to find services by name, the service set manages various queues.
758 * One is the queue for processes wishing to acquire the console. There is also a set of
759 * processes that want to start, and another set of those that want to stop. These latter
760 * two "queues" (not really queues since their order is not important) are used to prevent too
761 * much recursion and to prevent service states from "bouncing" too rapidly.
763 * A service that wishes to start or stop puts itself on the start/stop queue; a service that
764 * needs to propagate changes to dependent services or dependencies puts itself on the
765 * propagation queue. Any operation that potentially manipulates the queues must be followed
766 * by a "process queues" order (processQueues() method).
768 * Note that processQueues always repeatedly processes both queues until they are empty. The
769 * process is finite because starting a service can never cause services to stop, unless they
770 * fail to start, which should cause them to stop semi-permanently.
776 std::list<service_record *> records;
777 bool restart_enabled; // whether automatic restart is enabled (allowed)
779 shutdown_type_t shutdown_type = shutdown_type_t::CONTINUE; // Shutdown type, if stopping
781 // Services waiting for exclusive access to the console
782 dlist<service_record, extract_console_queue> console_queue;
784 // Propagation and start/stop "queues" - list of services waiting for processing
785 slist<service_record, extract_prop_queue> prop_queue;
786 slist<service_record, extract_stop_queue> stop_queue;
792 restart_enabled = true;
795 // Start the specified service. The service will be marked active.
796 void start_service(service_record *svc)
802 // Stop the specified service. Its active mark will be cleared.
803 void stop_service(service_record *svc)
809 // Locate an existing service record.
810 service_record *find_service(const std::string &name) noexcept;
812 // Load a service description, and dependencies, if there is no existing
813 // record for the given name.
815 // ServiceLoadException (or subclass) on problem with service description
816 // std::bad_alloc on out-of-memory condition
817 virtual service_record *load_service(const char *name)
819 auto r = find_service(name);
821 throw service_not_found(name);
826 // Start the service with the given name. The named service will begin
827 // transition to the 'started' state.
829 // Throws a ServiceLoadException (or subclass) if the service description
830 // cannot be loaded or is invalid;
831 // Throws std::bad_alloc if out of memory.
832 void start_service(const char *name)
835 service_record *record = load_service(name);
836 service_set::start_service(record);
839 void add_service(service_record *svc)
841 records.push_back(svc);
844 void remove_service(service_record *svc)
846 std::remove(records.begin(), records.end(), svc);
849 // Get the list of all loaded services.
850 const std::list<service_record *> &listServices()
855 // Stop the service with the given name. The named service will begin
856 // transition to the 'stopped' state.
857 void stopService(const std::string &name) noexcept;
859 // Add a service record to the state propagation queue. The service record will have its
860 // do_propagation() method called when the queue is processed.
861 void addToPropQueue(service_record *service) noexcept
863 if (! prop_queue.is_queued(service)) {
864 prop_queue.insert(service);
868 // Add a service record to the start queue. The service record will have its
869 // execute_transition() method called when the queue is processed.
870 void addToStartQueue(service_record *service) noexcept
872 // The start/stop queue is actually one queue:
873 addToStopQueue(service);
876 // Add a service record to the stop queue. The service record will have its
877 // execute_transition() method called when the queue is processed.
878 void addToStopQueue(service_record *service) noexcept
880 if (! stop_queue.is_queued(service)) {
881 stop_queue.insert(service);
885 // Process state propagation and start/stop queues, until they are empty.
886 void process_queues() noexcept
888 while (! stop_queue.is_empty() || ! prop_queue.is_empty()) {
889 while (! prop_queue.is_empty()) {
890 auto next = prop_queue.pop_front();
891 next->do_propagation();
893 while (! stop_queue.is_empty()) {
894 auto next = stop_queue.pop_front();
895 next->execute_transition();
900 // Set the console queue tail (returns previous tail)
901 void append_console_queue(service_record * newTail) noexcept
903 bool was_empty = console_queue.is_empty();
904 console_queue.append(newTail);
906 enable_console_log(false);
910 // Pull and dispatch a waiter from the console queue
911 void pull_console_queue() noexcept
913 if (console_queue.is_empty()) {
914 enable_console_log(true);
917 service_record * front = console_queue.pop_front();
918 front->acquiredConsole();
922 void unqueue_console(service_record * service) noexcept
924 if (console_queue.is_queued(service)) {
925 console_queue.unlink(service);
929 // Notification from service that it is active (state != STOPPED)
930 // Only to be called on the transition from inactive to active.
931 void service_active(service_record *) noexcept;
933 // Notification from service that it is inactive (STOPPED)
934 // Only to be called on the transition from active to inactive.
935 void service_inactive(service_record *) noexcept;
937 // Find out how many services are active (starting, running or stopping,
939 int count_active_services() noexcept
941 return active_services;
944 void stop_all_services(shutdown_type_t type = shutdown_type_t::HALT) noexcept
946 restart_enabled = false;
947 shutdown_type = type;
948 for (std::list<service_record *>::iterator i = records.begin(); i != records.end(); ++i) {
955 void set_auto_restart(bool restart) noexcept
957 restart_enabled = restart;
960 bool get_auto_restart() noexcept
962 return restart_enabled;
965 shutdown_type_t getShutdownType() noexcept
967 return shutdown_type;
971 class dirload_service_set : public service_set
973 const char *service_dir; // directory containing service descriptions
976 dirload_service_set(const char *service_dir_p) : service_set(), service_dir(service_dir_p)
980 service_record *load_service(const char *name) override;