sm.h

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/* -*- C -*- */
/*
 * Copyright (c) 2011-2020 Seagate Technology LLC and/or its Affiliates
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * For any questions about this software or licensing,
 * please email opensource@seagate.com or cortx-questions@seagate.com.
 *
 */


#pragma once

#ifndef __MOTR_SM_SM_H__
#define __MOTR_SM_SM_H__

#include "lib/types.h"               /* int32_t, uint64_t */
#include "lib/atomic.h"
#include "lib/time.h"                /* m0_time_t */
#include "lib/timer.h"
#include "lib/semaphore.h"
#include "lib/chan.h"
#include "lib/mutex.h"
#include "lib/tlist.h"
#include "addb2/histogram.h"

/* export */
struct m0_sm;
struct m0_sm_state_descr;
struct m0_sm_state_stats;
struct m0_sm_conf;
struct m0_sm_group;
struct m0_sm_ast;
struct m0_sm_addb2_stats;
struct m0_sm_group_addb2;
struct m0_sm_ast_wait;

/* import */
struct m0_timer;
struct m0_mutex;

struct m0_sm {
        uint32_t                   sm_state;
        uint64_t                   sm_id;
        const struct m0_sm_conf   *sm_conf;
        struct m0_sm_group        *sm_grp;
        m0_time_t                  sm_state_epoch;
        struct m0_sm_addb2_stats  *sm_addb2_stats;
        struct m0_chan             sm_chan;
        int32_t                    sm_rc;
        bool                       sm_invariant_chk_off;
};

struct m0_sm_conf {
        uint64_t                        scf_magic;
        const char                     *scf_name;
        uint32_t                        scf_nr_states;
        struct m0_sm_state_descr       *scf_state;
        uint32_t                        scf_trans_nr;
        struct m0_sm_trans_descr       *scf_trans;
        uint64_t                        scf_addb2_key;
        uint64_t                        scf_addb2_id;
        uint64_t                        scf_addb2_counter;
};

enum {
        M0_SM_MAX_STATES = 64
};

struct m0_sm_state_descr {
        uint32_t    sd_flags;
        const char *sd_name;
        int       (*sd_in)(struct m0_sm *mach);
        void      (*sd_ex)(struct m0_sm *mach);
        bool      (*sd_invariant)(const struct m0_sm *mach);
        uint64_t    sd_allowed;
        int8_t      sd_trans[M0_SM_MAX_STATES];
};

enum m0_sm_state_descr_flags {
        M0_SDF_INITIAL  = 1 << 0,
        M0_SDF_FAILURE  = 1 << 1,
        M0_SDF_TERMINAL = 1 << 2,
        M0_SDF_FINAL    = 1 << 3

};

struct m0_sm_trans_descr {
        const char *td_cause;   
        uint32_t    td_src;     
        uint32_t    td_tgt;     
};

struct m0_sm_ast {
        void              (*sa_cb)(struct m0_sm_group *grp, struct m0_sm_ast *);
        void               *sa_datum;
        struct m0_sm_ast   *sa_next;
        struct m0_sm       *sa_mach;
};

struct m0_sm_group {
        struct m0_mutex           s_lock;
        unsigned int              s_nesting;
        struct m0_clink           s_clink;
        struct m0_sm_ast         *s_forkq;
        struct m0_chan            s_chan;
        struct m0_sm_group_addb2 *s_addb2;
};

M0_INTERNAL void m0_sm_init(struct m0_sm *mach, const struct m0_sm_conf *conf,
                            uint32_t state, struct m0_sm_group *grp);
M0_INTERNAL void m0_sm_fini(struct m0_sm *mach);

M0_INTERNAL void m0_sm_group_init(struct m0_sm_group *grp);
M0_INTERNAL void m0_sm_group_fini(struct m0_sm_group *grp);

M0_INTERNAL void m0_sm_group_lock(struct m0_sm_group *grp);
M0_INTERNAL void m0_sm_group_unlock(struct m0_sm_group *grp);
M0_INTERNAL bool m0_sm_group_is_locked(const struct m0_sm_group *grp);
M0_INTERNAL void m0_sm_group_lock_rec(struct m0_sm_group *grp, bool runast);
M0_INTERNAL void m0_sm_group_unlock_rec(struct m0_sm_group *grp, bool runast);
M0_INTERNAL int m0_sm_timedwait(struct m0_sm *mach, uint64_t states,
                                m0_time_t deadline);

M0_INTERNAL void m0_sm_fail(struct m0_sm *mach, int fail_state, int32_t rc);

M0_INTERNAL void m0_sm_move(struct m0_sm *mach, int32_t rc, int state);

void m0_sm_state_set(struct m0_sm *mach, int state);

M0_INTERNAL const char *m0_sm_state_name(const struct m0_sm *mach, int state);
M0_INTERNAL const char *m0_sm_conf_state_name(const struct m0_sm_conf *conf,
                                              int state);

struct m0_sm_timer {
        struct m0_sm_group *tr_grp;
        struct m0_timer     tr_timer;
        struct m0_sm_ast    tr_ast;
        void              (*tr_cb)(struct m0_sm_timer *);
        int                 tr_state;
};

M0_INTERNAL void m0_sm_timer_init(struct m0_sm_timer *timer);
M0_INTERNAL void m0_sm_timer_fini(struct m0_sm_timer *timer);

M0_INTERNAL int  m0_sm_timer_start(struct m0_sm_timer *timer,
                                   struct m0_sm_group *group,
                                   void (*cb)(struct m0_sm_timer *),
                                   m0_time_t deadline);
M0_INTERNAL void m0_sm_timer_cancel(struct m0_sm_timer *timer);
M0_INTERNAL bool m0_sm_timer_is_armed(const struct m0_sm_timer *timer);


struct m0_sm_timeout {
        struct m0_sm_timer st_timer;
        struct m0_clink    st_clink;
        int                st_state;
        uint64_t           st_bitmask;
};

M0_INTERNAL void m0_sm_timeout_init(struct m0_sm_timeout *to);

M0_INTERNAL int m0_sm_timeout_arm(struct m0_sm *mach, struct m0_sm_timeout *to,
                                  m0_time_t timeout, int state,
                                  uint64_t bitmask);
M0_INTERNAL void m0_sm_timeout_fini(struct m0_sm_timeout *to);

M0_INTERNAL bool m0_sm_timeout_is_armed(const struct m0_sm_timeout *to);

M0_INTERNAL void m0_sm_ast_post(struct m0_sm_group *grp, struct m0_sm_ast *ast);

M0_INTERNAL void m0_sm_ast_cancel(struct m0_sm_group *grp,
                                  struct m0_sm_ast   *ast);

M0_INTERNAL void m0_sm_asts_run(struct m0_sm_group *grp);

enum m0_sm_return {
        M0_SM_BREAK = -1,
};

M0_INTERNAL void m0_sm_conf_trans_extend(const struct m0_sm_conf *base,
                                         struct m0_sm_conf *sub);
M0_INTERNAL void m0_sm_conf_extend(const struct m0_sm_state_descr *base,
                                   struct m0_sm_state_descr *sub, uint32_t nr);

M0_INTERNAL bool m0_sm_invariant(const struct m0_sm *mach);

M0_INTERNAL void m0_sm_conf_init(struct m0_sm_conf *conf);

M0_INTERNAL void m0_sm_conf_fini(struct m0_sm_conf *conf);

M0_INTERNAL bool m0_sm_conf_is_initialized(const struct m0_sm_conf *conf);

int m0_sm_group_call(struct m0_sm_group *group,
                     int (*cb)(void *), void *data);

struct m0_sm_addb2_stats {
        uint64_t             as_id;
        int                  as_nr;
        struct m0_addb2_hist as_hist[0];
};

struct m0_sm_group_addb2 {
        uint64_t             ga_forq;
        struct m0_addb2_hist ga_forq_hist;
};

M0_INTERNAL int m0_sm_addb2_init(struct m0_sm_conf *conf,
         uint64_t id, uint64_t counter);

M0_INTERNAL void m0_sm_addb2_fini(struct m0_sm_conf *conf);

M0_INTERNAL bool m0_sm_addb2_counter_init(struct m0_sm *sm);

struct m0_sm_ast_wait {
        bool               aw_allowed;
        struct m0_atomic64 aw_active;
        struct m0_chan     aw_chan;
};

M0_INTERNAL void m0_sm_ast_wait_init(struct m0_sm_ast_wait *wait,
                                     struct m0_mutex *ch_guard);
M0_INTERNAL void m0_sm_ast_wait_fini(struct m0_sm_ast_wait *wait);

M0_INTERNAL void m0_sm_ast_wait(struct m0_sm_ast_wait *wait);

M0_INTERNAL void m0_sm_ast_wait_post(struct m0_sm_ast_wait *wait,
                                     struct m0_sm_group *grp,
                                     struct m0_sm_ast *ast);

M0_INTERNAL void m0_sm_ast_wait_signal(struct m0_sm_ast_wait *wait);

M0_INTERNAL void m0_sm_ast_wait_prepare(struct m0_sm_ast_wait *wait,
                                        struct m0_clink *clink);
M0_INTERNAL void m0_sm_ast_wait_complete(struct m0_sm_ast_wait *wait,
                                         struct m0_clink *clink);
M0_INTERNAL void m0_sm_ast_wait_loop(struct m0_sm_ast_wait *wait,
                                     struct m0_clink *clink);

M0_INTERNAL void m0_sm_conf_print(const struct m0_sm_conf *conf);

M0_INTERNAL uint64_t m0_sm_id_get(const struct m0_sm *sm);


#endif /* __MOTR_SM_SM_H__ */

/*
 *  Local variables:
 *  c-indentation-style: "K&R"
 *  c-basic-offset: 8
 *  tab-width: 8
 *  fill-column: 80
 *  scroll-step: 1
 *  End:
 */