/* Copyright (C) 2014 Stony Brook University
   This file is part of Graphene Library OS.

   Graphene Library OS is free software: you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public License
   as published by the Free Software Foundation, either version 3 of the
   License, or (at your option) any later version.

   Graphene Library OS 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 Lesser General Public License for more details.

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

/*
 * shim_sysv.h
 *
 * This file includes functions and types for implementing System V IPC
 * functionality.
 */


#ifndef __SHIM_SYSV_H__
#define __SHIM_SYSV_H__

#include <shim_types.h>
#include <shim_handle.h>

enum sysv_type { SYSV_NONE, SYSV_MSGQ, SYSV_SEM, SYSV_SHM };

#define SYSV_TYPE_STR(type)     \
        ((type) == SYSV_MSGQ ? "MSGQ" :   \
        ((type) == SYSV_SEM  ? "SEM"  :   \
        ((type) == SYSV_SHM  ? "SHM"  :   \
         "")))

#define VALID_SYSV_TYPE(type)   \
        ((type) == SYSV_MSGQ || (type) == SYSV_SEM || (type) == SYSV_SHM)

struct sysv_score {
    IDTYPE                  vmid;
    unsigned long           score;
};

struct sysv_client {
    struct shim_ipc_port *  port;
    IDTYPE                  vmid;
    unsigned                seq;
};

struct shim_handle;

struct sysv_balance_policy {
    unsigned int    score_decay;
    unsigned int    score_max;
    unsigned int    balance_threshold;
    int (*migrate) (struct shim_handle * hdl, struct sysv_client * client);
};

int __balance_sysv_score (struct sysv_balance_policy * policy,
                          struct shim_handle * hdl,
                          struct sysv_score * scores, int nscores,
                          struct sysv_client * src, long score);

#define MSG_NOERROR 010000

#include <list.h>

struct __kernel_msgbuf {
    long mtype;     /* type of message */
    char mtext[];   /* message text */
};

#define MSG_QOBJ_SIZE   64

struct msg_qobj {
    void * next;
    char data[MSG_QOBJ_SIZE - sizeof(void *)];
} __attribute__((packed));

struct msg_item {
    void * next;
    unsigned short size;
    char data[];
} __attribute__((packed));

#define MSG_ITEM_DATA_SIZE(size)                                        \
    ((size) < MSG_QOBJ_SIZE - sizeof(struct msg_item) ? (size) :        \
     MSG_QOBJ_SIZE - sizeof(struct msg_item))

struct msg_ext_item {
    void * next;
    char data[];
} __attribute__((packed));

#define MSG_EXT_ITEM_DATA_SIZE(size)                                    \
    ((size) < MSG_QOBJ_SIZE - sizeof(struct msg_ext_item) ? (size) :    \
     MSG_QOBJ_SIZE - sizeof(struct msg_ext_item))

struct msg_req {
    struct msg_req *        next;
    unsigned short          size;
    int                     flags;
    struct sysv_client      dest;
} __attribute__((packed));

#define INIT_MSG_TYPE_SIZE      32

struct msg_type {
    long type;              /* type of the messages */
    struct msg_item * msgs, * msg_tail;
    struct msg_req  * reqs, * req_tail;
};

#define DEFAULT_MSG_QUEUE_SIZE      2048

#define MSG_SND_SCORE             1
#define MSG_RCV_SCORE             20
#define MSG_SCORE_DECAY           10
#define MSG_SCORE_MAX             200
#define MSG_BALANCE_THRESHOLD     100

struct msg_handle_backup {
    int     perm;           /* access permissions */
    int     nmsgs;          /* number of msgs */
    int     currentsize;    /* current size in bytes */
};

struct msg_backup {
    long    type;
    int     size;
    char    data[];
};

struct shim_msg_handle;

int add_msg_handle (unsigned long key, IDTYPE id, bool owned);
int del_msg_handle (struct shim_msg_handle * msgq);

struct shim_msg_handle * get_msg_handle_by_key (unsigned long key);
struct shim_msg_handle * get_msg_handle_by_id (IDTYPE id);

void put_msg_handle (struct shim_msg_handle * msgq);

int recover_msg_ownership (struct shim_msg_handle * msgq);

int add_sysv_msg (struct shim_msg_handle * msgq,
                  long type, size_t size, const void * data,
                  struct sysv_client * src);
int get_sysv_msg (struct shim_msg_handle * msgq,
                  long type, size_t size, void * data, int flags,
                  struct sysv_client * src);

int store_all_msg_persist (void);

#define HOST_SEM_NUM        65535

DEFINE_LIST(sem_ops);
struct sem_ops {
    LIST_TYPE(sem_ops)      progress;
    struct sem_stat {
        bool                completed;
        bool                failed;
        int                 nops;
        int                 current;
        unsigned long       timeout;
    } stat;
    struct sysv_client client;
    struct sembuf ops[];
};

DEFINE_LISTP(sem_ops);
struct sem_obj {
    unsigned short      num;
    unsigned short      val;
    unsigned short      zcnt;
    unsigned short      ncnt;
    IDTYPE              pid;
    PAL_NUM             host_sem_id;
    PAL_HANDLE          host_sem;
    LISTP_TYPE(sem_ops) ops;
    LISTP_TYPE(sem_ops) next_ops;
};


#define SEM_POSITIVE_SCORE(num)  ((num) < 5 ? 5 - (num) : 1)
#define SEM_ZERO_SCORE           20
#define SEM_NEGATIVE_SCORE(num)  (20 * (num))
#define SEM_SCORE_DECAY          10
#define SEM_SCORE_MAX            200
#define SEM_BALANCE_THRESHOLD    100

struct sem_backup {
    unsigned short      val;
    unsigned short      zcnt;
    unsigned short      ncnt;
    IDTYPE              pid;
};

struct sem_client_backup {
    IDTYPE          vmid;
    unsigned long   seq;
    int             current;
    int             nops;
};

int add_sem_handle (unsigned long key, IDTYPE id, int nsems, bool owned);
struct shim_sem_handle * get_sem_handle_by_key (unsigned long key);
struct shim_sem_handle * get_sem_handle_by_id (IDTYPE semid);
void put_sem_handle (struct shim_sem_handle * sem);
int del_sem_handle (struct shim_sem_handle * sem);

int recover_sem_ownership (struct shim_sem_handle * sem,
                           struct sem_backup * backups, int nbackups,
                           struct sem_client_backup * clients, int nclients);

int submit_sysv_sem (struct shim_sem_handle * sem, struct sembuf * sops,
                     int nsops, unsigned long timeout,
                     struct sysv_client * client);

#ifdef USE_SHARED_SEMAPHORE
int send_sem_host_ids (struct shim_sem_handle * sem,
                       struct shim_ipc_port * port, IDTYPE dest,
                       unsigned long seq);
#endif

#endif /* __SHIM_SYSV_H__ */