/*
    ChibiOS - Copyright (C) 2006,2007,2008,2009,2010,2011,2012,2013,2014,
              2015,2016,2017,2018,2019,2020,2021 Giovanni Di Sirio.

    This file is part of ChibiOS.

    ChibiOS is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation version 3 of the License.

    ChibiOS is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

/**
 * @startuml {rt_arch.png} "RT Core"
 * package "Lists and Queues" {
 *   class ch_list_t {
 *     - next: ch_list_t *
 *     + ch_list_init()
 *     + ch_list_isempty()
 *     + ch_list_notempty()
 *     + ch_list_push()
 *     + ch_list_pop()
 *   }
 *   class ch_queue_t {
 *     - next: ch_queue_t *
 *     - prev: ch_queue_t *
 *     + ch_queue_init()
 *     + ch_queue_isempty()
 *     + ch_queue_notempty()
 *     + ch_queue_insert()
 *     + ch_queue_fifo_remove()
 *     + ch_queue_lifo_remove()
 *     + ch_queue_dequeue()
 *   }
 *   class ch_pqueue_t {
 *     # next: ch_pqueue_t *
 *     # prev: ch_pqueue_t *
 *     # prio: tprio_t
 *     + ch_pqueue_init()
 *     + ch_pqueue_fifo_remove_highest()
 *     + ch_pqueue_insert_ahead()
 *     + ch_pqueue_insert_behind()
 *   }
 * }
 * 
 * package OS {
 *   class "Port Timer" <<(S,#FF7700) Singleton>> {
 *     + {static} port_timer_get_time()
 *   }
 * 
 *   class "Port Layer" <<(S,#FF7700) Singleton>> {
 *     + {static} port_init()
 *     + {static} port_lock()
 *     + {static} port_unlock()
 *     + {static} port_suspend()
 *     + {static} port_enable()
 *     + {static} port_disable()
 *     + {static} port_switch()
 *     + {static} port_wait_for_interrupt()
 *     + {static} port_rt_get_counter_value()
 *     + {static} port_get_core_id()
 *   }
 *   "Port Layer" .r.> "Port Timer" : use\ntick-less mode\nonly
 * 
 *   class System <<(S,#FF7700) Singleton>> {
 *     - {static} ch_system : ch_system_t
 *     - {static} ch0 : os_instance_t
 *     - {static} ch1 : os_instance_t
 *     ~ currcore: os_instance_t *
 *   }
 * 
 *   class tm_calibration_t {
 *     ~ offset : sysinterval_t
 *     ~ __tm_calibration_object_init()
 *   }
 * 
 *   class system_debug_t {
 *     # panic_msg : volatile char *
 *     # isr_cnt : cnt_t
 *     # lock_cnt : cnt_t
 *     ~ __dbg_object_init()
 *     + chDbgCheck()
 *     + chDbgAssert()
 *     + chDbgCheckClassI()
 *     + chDbgCheckClassS()
 *   }
 * 
 *   class trace_event_t {
 *   }
 * 
 *   class trace_buffer_t {
 *     - prt : trace_event_t *
 *     ~ __trace_object_init()
 *     + chTraceWrite()
 *     + chTraceSuspend()
 *     + chTraceResume()
 *   }
 *   trace_buffer_t "1" *-- "1..*" trace_event_t : trace events\nbuffer
 *   trace_buffer_t "1" o-- "1" trace_event_t : next\nwritten
 * 
 *   class kernel_stats_t {
 *     # n_irq : ucnt_t
 *     # n_ctxswc : ucnt_t
 *     # m_crit_thd : time_measurement_t
 *     # m_crit_isr : time_measurement_t
 *     ~ __stats_object_init()
 *   }
 * 
 *   class registry_t {
 *     - queue : ch_queue_t
 *     ~ __reg_object_init()
 *     + {static} chRegFirstThread()
 *     + {static} chRegNextThread()
 *     + {static} chRegFindThreadByName()
 *     + {static} chRegFindThreadByPointer()
 *     + {static} chRegFindThreadByWorkingArea()
 *   }
 *   registry_t "1" o-- "1--*" thread_t : alive\nthreads
 * 
 *   class ch_system_t {
 *     + state : ch_system_state_t
 *     - reglist : registry_t
 *     - tmc : tm_calibration_t
 *     - instances[] : os_instance_t *
 *     + {static} chSysInit()
 *     + {static} chSysLock()
 *     + {static} chSysUnlock()
 *     + {static} chSysLockFromISR()
 *     + {static} chSysUnlockFromISR()
 *     + {static} chSysSwitch()
 *   }
 *   ch_system_t .u.> "Port Layer" : use
 *   ch_system_t *-- "1" registry_t : SMP\nonly
 *   ch_system_t *-r- "1" tm_calibration_t
 *   ch_system_t "1" o-- "1..*" os_instance_t : registered\ninstances\none for\neach core
 * 
 *   class os_instance_t {
 *     ~ core_id : core_id_t
 *     ~ rlist : ready_list_t
 *     ~ vtlist : virtual_timers_list_t
 *     ~ reglist : registry_t
 *     ~ mainthread : thread_t
 *     ~ dbg : system_debug_t
 *     ~ trace_buffer : trace_buffer_t
 *     ~ kernel_stats : kernel_stats_t
 *     + chInstanceObjectInit()
 *     ~ __instance_get_currthread()
 *     ~ __instance_set_currthread()
 *   }
 *   os_instance_t *-- "1" thread_t : Main\nThread
 *   os_instance_t *-- "1" registry_t : Non-SMP\nonly
 *   os_instance_t *-- "1" system_debug_t
 *   os_instance_t *-- "1" trace_buffer_t
 *   os_instance_t *-- "1" kernel_stats_t
 * 
 *   class thread_t {
 *     .. union ..
 *     - list : ch_list_t
 *     - queue : ch_queue_t
 *     - pqueue : ch_pqueue_t
 *     .. end union ..
 *     - state : tstate_t
 *     - owner : os_instance_t
 *     - rqueue : ch_queue_t
 *     - ctx : port_context
 *     - waiting: ch_list_t
 *     + {static} chThdCreate()
 *     + {static} chThdSleep()
 *     + {static} chThdSleepUntil()
 *     + {static} chThdExit()
 *     + chThdWait()
 *     + chThdAddRef()
 *     + chThdRelease()
 *   }
 *   thread_t o-- "0..*" thread_t : threads waiting\nfor termination
 *   thread_t o-- "1" os_instance_t : owner\ninstance
 * 
 *   class ready_list_t {
 *     - pqueue : ch_pqueue_t
 *     - current : thread_t *
 *     + {static} chSchReadyI()
 *     + {static} chSchWakeupS()
 *     + {static} chSchGoSleepS()
 *     + {static} chSchGoSleepTimeoutS()
 *   }
 *   ready_list_t "1" o-- "1..*" thread_t : ready\nthreads
 *   ready_list_t "0..1" o-- "1" thread_t : current\nthread
 *   ready_list_t "1" --* os_instance_t : instance\nready list
 * }
 * 
 * OS ..> "Lists and Queues" : use
 * System *-- "1" ch_system_t : system\nroot object
 * System *-- "1..2" os_instance_t : predefined\ninstances
 * System o.. "1" os_instance_t : current core/instance\nmediated by\nport layer
 * 
 * package "Virtual Timers" {
 *   class delta_list_t {
 *     - next : delta_list_t *
 *     - prev : delta_list_t *
 *     - delta : sysinterval_t
 *   }
 * 
 *   class virtual_timer_t {
 *     - dlist : delta_list_t
 *     - func : vtfunc_t
 *     - par : void *
 *     + {static} chVTDoTickI()
 *     + chVTObjectInit()
 *     + chVTSet()
 *     + chVTReset()
 *   }
 *   virtual_timer_t <.. ready_list_t : use
 *   virtual_timer_t *-- "1" delta_list_t
 * 
 *   class virtual_timers_list_t {
 *     - dlist : delta_list_t
 *     - systime : systime_t
 *     - lasttime : systime_t
 *     - laststamp : uint64_t
 *     # __vt_object_init()
 *   }
 *   virtual_timers_list_t o-- "0..*" virtual_timer_t : active timers
 *   virtual_timers_list_t *-- "1" delta_list_t
 *   virtual_timers_list_t "1" --* os_instance_t
 *   virtual_timers_list_t ..> "Port Timer" : use\ntick-less mode\nonly
 * }
 * 
 * @enduml
 *
 * @startuml {rt_arch.png} "RT Synchronization"
 * package OS {
 *   class thread_t {
 *     - queue: ch_queue_t
 *     - wtmtxp: mutex_t *
 *   }
 * }
 * package "Lists and Queues" {
 *   class ch_list_t
 *   class ch_queue_t
 * }
 * package "Low Level Synchronization" {
 * 
 *   class thread_reference_t {
 *     - ref : thread_t *
 *     + chThdSuspendS()
 *     + chThdSuspendTimeoutS()
 *     + chThdResumeI()
 *     + chThdResumeS()
 *   }
 *   class threads_queue_t {
 *     - queue: ch_queue_t
 *     + chThdQueueObjectInit()
 *     + chThdEnqueueTimeoutS()
 *     + chThdDequeueNextI()
 *     + chThdDequeueAllI()
 *   }
 * }
 * package Messages {
 *   class messages <<(S,#FF7700) Singleton>> {
 *     + {static} chMsgWait()
 *     + {static} chMsgGet()
 *     + {static} chMsgRelease()
 *     + {static} chMsgSend()
 *   }
 * }
 * package Semaphores {
 *   class semaphore_t {
 *     - queue: ch_queue_t
 *     - cnt : cnt_t
 *     + chSemObjectInit()
 *     + chSemWait()
 *     + chSemWaitTimeout()
 *     + chSemSignal()
 *     + chSemReset()
 *   }
 * }
 * package Monitors {
 *   class mutex_t {
 *     - queue: ch_queue_t
 *     - owner : thread_t *
 *     - next : mutex_t *
 *     - cnt : cnt_t
 *     + chMtxObjectInit()
 *     + chMtxLock()
 *     + chMtxTryLock()
 *     + chMtxUnlock()
 *     + chMtxUnlockAll()
 *   }
 *   class condition_variable_t {
 *     - queue: ch_queue_t
 *     + chCondObjectInit()
 *     + chCondSignal()
 *     + chCondBroadcast()
 *     + chCondWait()
 *     + chCondWaitTimeout()
 *   }
 *   mutex_t "1" .l. "0..*" condition_variable_t : indirect\ncollaboration
 *   mutex_t o-- "0..*" thread_t : waiting\nthreads
 *   mutex_t o-- "0..1" thread_t : owner\nthread
 *   mutex_t o-- "0..1" mutex_t : next\nowned mutex
 *   condition_variable_t o-- "0..*" thread_t : waiting\nthreads
 * }
 * 
 * messages -u- thread_t : collaboration
 * 
 * package Events {
 *   class events <<(S,#FF7700) Singleton>> {
 *     + {static} chEvtSignal()
 *     + {static} chEvtWaitOne()
 *     + {static} chEvtWaitAny()
 *     + {static} chEvtWaitAll()
 *     + {static} chEvtDispatch()
 *   }
 *   class event_source_t {
 *     - next : event_listener_t *
 *     + chEvtObjectInit()
 *     + chEvtRegister()
 *     + chEvtBroadcastFlags()
 *   }
 *   class event_listener_t {
 *     - next : event_listener_t *
 *     - listener : thread_t *
 *     - events : eventmask_t
 *     - flags : eventflags_t
 *     - wflags : eventflags_t
 *   }
 *   event_source_t "1" o-- "0..*" event_listener_t : registered\nlisteners
 *   event_listener_t o-- "1" event_listener_t : next\nregistered\nlistener
 *   event_listener_t "0..*" o-- "1" thread_t : listening\nthread
 * }
 * 
 * events -u- thread_t : collaboration
 * 
 * thread_reference_t o-- "0..1" thread_t : referred\nthread
 * 
 * threads_queue_t o-- "0..*" thread_t : queued\nthreads
 * 
 * ch_queue_t "1" --* threads_queue_t
 * ch_queue_t "1" --* semaphore_t
 * ch_queue_t "1" --* mutex_t
 * ch_queue_t "1" --* condition_variable_t
 * 
 * thread_t o-- "0..*" mutex_t: owned\nmutexes
 * 
 * semaphore_t o-- "0..*" thread_t : waiting\nthreads
 * 
 * @enduml
 */