ser_main.c

lpc implement for distribut

#include <stdio.h>
#include <sys/types.h>
#include <unistd.h>
#include <sys/ipc.h>
#include <sys/msg.h>
#include <stdlib.h>
#include "mymsg.h"

void   door_create(void (* proc)(),int flag);
void   door_server_proc1(char *,size_t);
void   door_server_proc2(char *,size_t);
key_t  fattach(char *,int);
int    door_return(char *,size_t);
int    ltos(char*,long,int);

static int door_msg_id1=-1;
static int door_msg_id2=-1;
key_t     key_id1,
          key_id2;
message   *rcv_msg1,*rcv_msg2,
          *snd_msg1,*snd_msg2;
int       rcv_len1,rcv_len2,
          snd_len1,snd_len2;

char *result;

int main(int argc,char **argv)
{
  if (argc != 4)
  {
    error_quit("usage: server <server_pathname1> <server_pathname1> ");
    exit (1);
  }
  door_msg_id1 = fattach(argv[1],IPC_CREAT|0666);
  door_msg_id1 = fattach(argv[2],IPC_CREAT|0666);
  while (1)
  {
    door_create(door_server_proc1,door_msg_id1);
    door_create(door_server_proc2,door_msg_id2);
   }
  exit (0);
}

void door_create(void (* proc)(char * ptr,size_t data_size),int flag)
{
  int     data_len,
          rcv_len,
          n;
  char    str[16];
  printf("\n----waiting for receive client request----\n");
  rcv_msg = (message *)malloc(MAXSIZE);
  rcv_len = msgrcv(flag,rcv_msg,MAXSIZE+2*sizeof(long),CLIENT_INPUT,0);
  if (rcv_len == -1)
  {
       error_quit("!!!receive client request error!!!");
       continue;      
  }
  data_len = rcv_len - sizeof(long);
  strncpy(str,rcv_msg->m_buf,data_len);
  str[data_len] = '\0';
  (*proc)(str,data_len);
  free(rcv_msg);
}

//computing square
void door_server_proc1(char *ptr,size_t data_size)
{
  int  n;
  long result;
  char lptr[20];
  n = atoi(ptr);
  result = n*n;
  ltos(lptr,result,20);
  door_return(lptr,strlen(lptr));
}

//computing max_string
void door_server_proc2(char *ptr,size_t data_size)
{
  int  n;
  char *re1,
       re2[MAXSIZE],
       result[MAXSIZE];
  re1 = strstr(ptr,'+');
  n = strlen(ptr)-strlen(re1);
  strncpy(re2,ptr,n);
  re2[n] ='\0';
  ++re1;
  re1[str(re1)+1] ='\0';
  if (strcmp(re1,re2) > 0)
     strcpy(result,re1);
  else
     strcpy(result,re2);
  door_return(result,strlen(result));
}

int door_return(char *ptr,size_t data_size)
{ 
  int  ret;
  int  size;
  size = 2*sizeof(long) + data_size + 1;
  ptr[data_size] = '\0';
  snd_msg = (message *)malloc(MAXSIZE);
  snd_msg->m_type = rcv_msg->process_id;
  snd_msg->process_id = getpid();
  strcpy(snd_msg->m_buf,ptr);
  snd_len = sizeof(snd_msg) - sizeof(long);
  if ((ret = msgsnd(door_msg_id,snd_msg,snd_len,0)) < 0)
  {
    error_quit(" !!!send result to client error!!! ");
    exit (1);
  }
  printf("----send the result to client----\n");
  free(snd_msg);
  return (0);
}
int fattach(char *pathname,int flag)
{
  int door=-1;
  key_id = ftok(pathname,'1');
  if (key_id == -1)
  {
     error_quit("!!!attatch the file to door error,no the file!!! ");
     return (-1);
     exit (1);
  }
  door_id = msgget(key_id,0);
  if (door_id!= -1)
  {
    if ((n = msgctl(door_id,IPC_RMID,NULL)) == -1)
    {
       error_quit("!!!remove old door list error!!!");
       exit (1);
    }
  }
  door_id = msgget(key_id,flag);
  if (door_id == -1)
  {
     error_quit("!!!create new door list error!!!");
     exit (1);
  }
  return (door_id);
}

int ltos(char* str,long num,int size)
{
  int i;
  long temp;
  temp=num;
  if(temp==0)
  {
    memset(str,'0',size); 
    return 1;
  }
  for(i=0;i<size-1;i++)
  {
   if(num > 0)
   {
	str[size-2-i] = num % 10 + '0';
	num /= 10;
   }
   else
    str[size-2-i] =' ';
  }
  str[size-1] = '\0';
  return (0);
}