ipc.c

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/*
  ipc.c --  IPC opreation
*/

#include	<stdio.h>
#include	<sys/types.h>
#include	<sys/ipc.h>
#include	<sys/msg.h>
#include 	<sys/sem.h>
#include 	<errno.h>
#include 	<fcntl.h>

#include	"mytools.h"
#include	"msgsys.h"

extern int	errno;



key_t	getipckey ( msgfile, id )
char	* msgfile;
char	id;
{
int 	fd;
char 	*filename;

#ifndef wyz_mod_0518
	filename = (char *) getfname("WORKDIR", msgfile);
#else
	filename = (char *) getfname("TrCPDIR" , msgfile);
#endif

#ifdef DEBUG1_del
	printf("getipckey file %s\n", filename);
#endif

	fd = open(filename, O_CREAT|O_EXCL);
	if (fd == -1 && errno != EEXIST) 
		return((key_t)-1);
	close(fd);
	return (ftok(filename, id));
}



char	* creat_shm ( shmfile, id, len )
char	* shmfile;
char	id;
int	len;
{
	int	shmid;
	key_t	key;
	char	* shmptr;
	

	if ( ( key = getipckey ( shmfile, id ) ) < 0 ) {

		errcall ( ERROR, "getipckey( %s, %d ) return %d",
						shmfile, id, key );
		return ( NULL );
	}
	
	if ( ( shmid = shmget ( key, len, IPCCREAT | 0666 ) ) < 0 ) {

		errcall ( ERROR, "%d shmget(key=%d) return errno=%d",
						getpid(),	key, errno );
		return ( NULL );
	}


	if ( ( shmptr = ( char * ) shmat ( shmid, 0, 0 ) ) == (char *)(-1) ) {

		errcall ( ERROR, "shmat(key=%d) return errno=%d",
							key, errno );
		return ( NULL );
	}

	return ( shmptr );
}



char	* get_shm (shmfile, id, len)
char	*shmfile;
char	id;
int	len;
{
	int shmid;
	key_t key;
	char *shmptr;
	

	if ( ( key = getipckey ( shmfile, id ) ) < 0 ) {

		errcall ( ERROR, "getipckey( %s, %d ) return %d", shmfile, id, key );
		return ( NULL );
	}


	if ( ( shmid = shmget ( key, len, IPCGET ) ) < 0 ) {

		errcall ( ERROR, "pid = %d shmget(key=0x%x) return errno=%d", getpid (),key, errno );
		return ( NULL );
	}


	if ( ( shmptr = ( char * ) shmat ( shmid, 0, 0 ) ) == NULL ) {

		errcall ( ERROR, "shmat(key=%d) return errno=%d", key, errno );
		return ( NULL );
	}

	return ( shmptr );
}



dt_shm ( shmptr )
char	* shmptr;
{

	if ( shmdt ( shmptr ) < 0 ) {

		errcall ( ERROR, "shmdt() return errno=%d", errno );
		return ( -1 ) ;
	}

	return ( 0 );
}




rm_shm ( shmfile, id )
char	*shmfile;
char	id;
{
	key_t	key;
	int	shmid;

	if ( ( key = getipckey ( shmfile, id ) ) < 0 ) {

		errcall ( ERROR, "getipckey( %s, %d ) return %d",
						shmfile, id, key );
		return ( -1 );
	}


	if ( ( shmid = shmget ( key, 0, IPCGET ) ) < 0 ) {

		errcall ( ERROR, "shmget(key=%d) return errno=%d",
							key, errno );
		return ( -1 );
	}


	if ( shmctl ( shmid, IPC_RMID, NULL ) < 0 ) {
		int	zz;
		zz = errno;
		errcall ( ERROR, "shmctl(key=%x,IPC_RMID) return errno=%d",
								key, zz );
		return ( -1 );
	}


	return ( 0 );
}

int creat_sem ( char *IPC_FILE , int id , int sem_number )
{
	int semid;
	key_t key;
	int i;

	if ( ( key = getipckey ( IPC_FILE, id ) ) < 0 ) {
		errcall ( ERROR, "getipckey( %s, %d ) return %d",
						IPC_FILE, id, key );
		return ( -1 );
	}

	if ( ( semid = semget ( key , sem_number , IPC_CREAT|0666 ) ) < 0 ) {
		errcall ( ERROR , "Unable semget (shmfile = %s shmid = %d)!" ,\
		IPC_FILE , id  );

		return -1;
	}
	
	for ( i=0 ; i<sem_number ; i++ ) 
		semctl ( semid , i , SETVAL , 0 );
	
	return semid;
}

/***
int get_sem ( char *IPC_FILE , int id , int sem_number )
{
	int semid;
	key_t key;
	int i;

	if ( ( key = getipckey ( IPC_FILE, id ) ) < 0 ) {
		errcall ( ERROR, "getipckey( %s, %d ) return %d",
						IPC_FILE, id, key );
		return ( -1 );
	}

	if ( ( semid = semget ( key , sem_number , 0 ) ) < 0 ) {
		errcall ( ERROR , "Unable semget (shmfile = %s shmid = %d)!" ,\
		IPC_FILE , id  );

		return -1;
	}
	
	return semid;
}
***/

rm_sem ( IPC_FILE, id )
char	*IPC_FILE;
char	id;
{
	key_t	key;
	int	semid;

	if ( ( key = getipckey ( IPC_FILE, id ) ) < 0 ) {

		errcall ( ERROR, "getipckey( %s, %d ) return %d",
						IPC_FILE, id, key );
		return ( -1 );
	}


	if ( ( semid = semget ( key, 0, IPCGET ) ) < 0 ) {

		errcall ( ERROR, "semget(key=%d) return errno=%d",
							key, errno );
		return ( -1 );
	}


	if ( semctl ( semid, 0, IPC_RMID, 0 ) < 0 ) {
		int	zz;
		zz = errno;
		errcall ( ERROR, "semctl(key=%x,IPC_RMID) return errno=%d",
								key, zz );
		return ( -1 );
	}


	return ( 0 );
}

int sem_P ( int semid , int number , int sem_flag )
{
	struct sembuf op_lock[1];

	op_lock[0].sem_num = number;
	op_lock[0].sem_op  = -1;
	op_lock[0].sem_flg = sem_flag;

	if ( semop (semid , op_lock, 1) <0 )
		return -1;
	else 
		return 0;
}

int sem_V ( int semid , int number , int sem_flag )
{
	struct sembuf op_unlock[1];

	op_unlock[0].sem_num = number;
	op_unlock[0].sem_op  = 1;
	op_unlock[0].sem_flg = sem_flag;

	if ( semop (semid , op_unlock, 1) <0 )
		return -1;
	else 
		return 0;
}