/* helloSendData.c */

#include <stdio.h>
#include "pscomm.h"

#ifdef PS_RT_LINUX
#   include "/usr/src/rtlinux-2.2/drivers/mbuff/mbuff.h"
#endif

#ifndef PS_RT_LINUX
#   include <sys/ipc.h>
#   include <sys/shm.h>
#endif

volatile char * shm1, *shm2, *shmControl;

#ifndef PS_RT_LINUX
   int shm1id, shm2id, shmcid;
#endif 

static struct TimeTable tt;

// initialization procedure
int ps_init(void) {

#ifndef PS_RT_LINUX
   int shmflg;
   fprintf(stdout,"LINUX PACKET SENDER INIT\n");

   // Create shm segment
   shmflg = IPC_CREAT | 511;

   shm1id = shmget(SHM1_KEY, sizeof(tt), shmflg);
   shm2id = shmget(SHM2_KEY, sizeof(tt), shmflg);
   shmcid = shmget(SHMC_KEY, 1024, shmflg);
   
   if ((shm1id < 0) || (shm2id < 0) || (shmcid < 0)) return -1;

   // attach shm
   shm1 = shmat(shm1id, NULL, 0);
   shm2 = shmat(shm2id, NULL, 0);
   shmControl = shmat(shmcid, NULL, 0);

   // try to prevent swapping - works only  for super-user 
   shmctl(shm1id, SHM_LOCK, 0);
   shmctl(shm2id, SHM_LOCK, 0);
   shmctl(shmcid, SHM_LOCK, 0);


#endif
 
#ifdef PS_RT_LINUX
   // if RT-Linux
   fprintf(stdout,"RT-LINUX PACKET SENDER INIT\n");
   // Shared memory alloc
   shm1 = (volatile char*) mbuff_alloc("tt1",sizeof(tt));
   shm2 = (volatile char*) mbuff_alloc("tt2",sizeof(tt));   
   if( shm1 == NULL || shm2 == NULL ) {
      //fprintf(stderr,"mbuff_alloc failed\n");
      return -1;
   }         

   shmControl = (volatile char*) mbuff_alloc("control",1024);   
   if( shmControl == NULL) {
      //fprintf(stderr,"mbuff_alloc failed\n");
      return -1;
   }         
#endif
   return 0;
}

int ps_getptrs(volatile char **shm1p, volatile char **shm2p, volatile char **shmControlp) {
   shm1p[0] = shm1;
   shm2p[0] = shm2;
   shmControlp[0] = shmControl;
   if ( shm1 == NULL || shm2 == NULL || shmControl == NULL) return -1;
   return 0;
}

// sends one time table to the packet sender
int ps_send(struct TimeTable *ttptr) {
   int ret = 0;
   int sent = 0;
   while( sent != 1) {

      // Wait for control info
      if (shmControl[0] == ACK) usleep(9000);

      if (shmControl[0] == URG_REQ_1 ) {
         // Sent DATA was late 
         // the sending process had to wait for the reading of new timing information 
         //fprintf(stderr,"Late 1\n");

         shmControl[0] = REQ_1;

         // Something should be done to avoid this if possible  
         ret = 1;
      } 

      if (shmControl[0] == URG_REQ_2 ) {
         // Sent DATA was late 
         // the sending process had to wait for the reading of new timing information 
         //fprintf(stderr,"Late 2\n");
 
         shmControl[0] = REQ_2;

         // Something should be done to avoid this if possible  
         ret = 1;
      } 


      if ( shmControl[0] == REQ_1 ) {
         sent++;

         // Send data
         memcpy((void *)shm1,ttptr,sizeof(tt));

         fprintf(stderr,"%i bytes written\n", sizeof(tt));
         shmControl[0] = ACK;

      } else if ( shmControl[0] == REQ_2 ) {
         sent++;

         // Send data
         memcpy((void *)shm2,ttptr,sizeof(tt));
    
         fprintf(stderr,"%i bytes written\n", sizeof(tt));
         shmControl[0] = ACK;

      } else if ( shmControl[0] != ACK ) {
         fprintf(stderr,"%c - Unexpected control info\n", shmControl[0]);
         ret = -1;
         sent = 1;
      }
   }
   return ret;
}


// cleanup 
int ps_cleanup(void) {
#ifndef PS_RT_LINUX

   struct shmid_ds shmid_ds_buf;

   // detach sgm
   shmdt((char*)shm1);
   shmdt((char*)shm2);
   shmdt((char*)shmControl);

   // check shm status
   shmctl(shm1id, IPC_STAT, &shmid_ds_buf);
   if (shmid_ds_buf.shm_nattch == 0) {
      // destroy shm segment
      shmctl(shm1id, IPC_RMID, 0);
   }

   // check shm status
   shmctl(shm2id, IPC_STAT, &shmid_ds_buf);
   if (shmid_ds_buf.shm_nattch == 0) {
      // destroy shm segment
      shmctl(shm2id, IPC_RMID, 0);
   }

   // check shm status
   shmctl(shmcid, IPC_STAT, &shmid_ds_buf);
   if (shmid_ds_buf.shm_nattch == 0) {
      // destroy shm segment
      shmctl(shmcid, IPC_RMID, 0);
   }

#endif

#ifdef PS_RT_LINUX
   // if RT-Linux 
   // Free shared memory
   mbuff_free("tt1",(void*)shm1);
   mbuff_free("tt2",(void*)shm2); 
   mbuff_free("control",(void*)shmControl); 
#endif
   return 0;
}