/*
 *
 * CreateProcess - Forks off a process, and runs the passed function
 * with the passed integer parameter.
 *
 * Modified from prodcons.c by Theo Van Dinter, 96/09/09
 *
 *
 */

#include "mailbox.h"

/*
 * CreateProcess - 96/09/09
 *
 * CreateProcess will now take two parameters, and pass the second to the
 * forked child.
 *
 */
int CreateProcess(int (*pFunc)(),int dvalue)
{
    int pid;

    if ((pid = fork()) == 0) /* We're the child */
      {
        (*pFunc)(dvalue); /* Call function with value */
        exit(0); /* If function doesn't quit, we'll die implicitly */
      }
    return(pid); /* Return fork() value to the parent (-1 for error, PID
		    otherwise) */
}

/*
 * InitMailbox - 96/09/09
 *
 * By: Theo Van Dinter (felicity@kluge.net)
 *
 * Initializes semaphores and shared memory "mailboxes".
 *
 * No calling parameters
 * Returns a -1 on error, 0 if ok.
 *
 */
int InitMailbox()
{
  int loop;

  for(loop=0;loop<NUMPROC;loop++) /* Create needed semaphores and mailboxes*/
    {
      semid[2*loop]=screate(1); /* We can send to all to start */
      semid[2*loop+1]=screate(0); /* But we can't receive yet */
      if (semid[2*loop]==-1 || semid[2*loop+1]==-1) /* Failure! */
	{
	  printf("screate() failed!\n");
	  return(-1);
	}

      /* Create initial "mailbox" with 0's for all message values */
      inbox[loop] = (struct msg *)shmcreate(sizeof(struct msg));
      inbox[loop]->iFrom=0;
      inbox[loop]->wType=0;
      inbox[loop]->wVal1=0;
      inbox[loop]->wVal2=0;
      inbox[loop]->wTotal=0;
    }
  return(0);
}

/*
 * CleanMailbox - 96/09/09
 *
 * By: Theo Van Dinter (felicity@kluge.net)
 *
 * Cleans up all semaphores and shared memory allocations.
 *
 * No calling parameters
 * Returns a -1 on error, 0 if ok.
 *
 */
int CleanupMailbox()
{
  int loop;

  for(loop=0;loop<NUMPROC;loop++)
    {
      if (shmdelete((struct msg *)inbox[loop])==-1) /* Failure */
	/* Delete shared memory */
	{
	  printf("shmdelete() failed!\n");
	  return(-1);
	}
      if (sdelete(semid[2*loop])==-1 || sdelete(semid[2*loop+1])==-1)
	/* Delete semaphores if possible */
	{
	  printf("sdelete() failed!\n");
	  return(-1);
	}
    }
  return(0);
}