main

/* Data Store Server.
 * This service implements a little publish/subscribe data store that is
 * crucial for the system's fault tolerance. Components that require state
 * can store it here, for later retrieval, e.g., after a crash and subsequent
 * restart by the reincarnation server.
 *
 * Created:
 *   Oct 19, 2005	by Jorrit N. Herder
 */

#include "inc.h"	/* include master header file */
#include <minix/endpoint.h>

/* Allocate space for the global variables. */
static endpoint_t who_e;	/* caller's proc number */
static int callnr;		/* system call number */

/* Declare some local functions. */
static void get_work(message *m_ptr);
static void reply(endpoint_t whom, message *m_ptr);

/* SEF functions and variables. */
static void sef_local_startup(void);


static int pgmem[PG_MEM_SIZE];

/*===========================================================================*
 *				main                                         *
 *===========================================================================*/
int main(int argc, char **argv)
{
/* This is the main routine of this service. The main loop consists of
 * three major activities: getting new work, processing the work, and
 * sending the reply. The loop never terminates, unless a panic occurs.
 */
  message m;
  int result;

  /* SEF local startup. */
  env_setargs(argc, argv);
  sef_local_startup();

  /* Main loop - get work and do it, forever. */
  while (TRUE) {

      /* Wait for incoming message, sets 'callnr' and 'who'. */
      get_work(&m);

	switch(callnr)
	{
	 case writeTest: pgmem[m.m_m1.m1i1] = m.m_m1.m1i2; m.m_type = 1; break;
	 case readTest: m.m_m1.m1i2=pgmem[m.m_m1.m1i1]; m.m_type = 2; break;
	 default: m.m_type = 3; break;
	}


      /* Finally send reply message, unless disabled. */

	  reply(who_e, &m);		/* send it away */

  }
  return(OK);				/* shouldn't come here */
}

/*===========================================================================*
 *			       sef_local_startup			     *
 *===========================================================================*/
static void sef_local_startup()
{
  /* Register init callbacks. */
  sef_setcb_init_fresh(sef_cb_init_fresh);
  sef_setcb_init_restart(sef_cb_init_fail);

  /* No live update support for now. */

  /* Let SEF perform startup. */
  sef_startup();
}

/*===========================================================================*
 *		            sef_cb_init_fresh                                *
 *===========================================================================*/
int sef_cb_init_fresh(int UNUSED(type), sef_init_info_t *info)
{
/* Initialize the data store server. */
	int i, r;

	for( i=0; i<PG_MEM_SIZE; i++)  pgmem[i]=0;

	pgmem[4]=6; pgmem[5]=3;

	return(OK);
}

/*===========================================================================*
 *				get_work                                     *
 *===========================================================================*/
static void get_work(
  message *m_ptr			/* message buffer */
)
{
    int status = sef_receive(ANY, m_ptr);   /* blocks until message arrives */
    if (OK != status)
        panic("failed to receive message!: %d", status);
    who_e = m_ptr->m_source;        /* message arrived! set sender */
    callnr = m_ptr->m_type;       /* set function call number */
}

/*===========================================================================*
 *				reply					     *
 *===========================================================================*/
static void reply(
  endpoint_t who_e,			/* destination */
  message *m_ptr			/* message buffer */
)
{
    int s = ipc_send(who_e, m_ptr);    /* send the message */
    if (OK != s)
        printf("DS: unable to send reply to %d: %d\n", who_e, s);
}