여러 생산자와 여러 소비자문제...

 
 
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/shm.h>
#include <sys/sem.h>
#include <sys/ipc.h>
#include <sys/types.h>
#include <fcntl.h>
#include <signal.h>
#include <errno.h>
 
#define MAX_Q_SIZE 10
#define MAX_PRODUCT_SIZE 1  							// product process number
#define MAX_CUSTOMER_SIZE 1								// customer process number 
#define MAX_PROCESS (MAX_PRODUCT_SIZE+MAX_CUSTOMER_SIZE)// total process number
 
/* init variable */
int sem_id;				// for mutex, mutex = 1
int full_sem_id;		// for empty semaphore, full = 0
int empty_sem_id;		// for empty semaphore, empty = n
int temp = 0;
 
 
/* job process ft */
void tfunc_a();				// product process
void tfunc_b();				// customer process
 
/* sem ft */
int sysv_semget(char *tok, key_t sem_fixkey, int n_sem, int sem_value, int user_mode);
int sysv_semrm(int sem_id);
int sysv_semwait(int sem_id, int sem_idx);
int sysv_sempost(int sem_id, int sem_idx);
int sysv_semval(int sem_id, int sem_idx);
 
/* define of semaphore union struct */
union semun {
	int val;                    
	struct semid_ds *buf;       
	unsigned short int *array;  
	struct seminfo *__buf;      
};
 
/* Name : main
 * Desc : Main function
 * Argv : int argc, char *argv
 * Ret  : void
 */
int main(int argc,char *argv[])
{
	int i,status;
 
	/* sem id getting */
	sem_id = sysv_semget(NULL, 0x12340001, 1, 1, 0660);
	empty_sem_id = sysv_semget(NULL, 0x12340002, 1, MAX_Q_SIZE, 0660);
	full_sem_id = sysv_semget(NULL, 0x12340003, 1, 0, 0660);
 
	/* fork */
	for (i=0;i<MAX_PROCESS;i++) {
		switch(fork()) {
			case 0: /* child */
 
				/* decide of process content */
				if ( i >= 0 && i < MAX_CUSTOMER_SIZE ) {
					tfunc_b();
				} else {
					tfunc_a();
 
				}
 
				exit(0);
			case -1:
				perror("fork() error\n");
				exit(-1);
			default:
				break;
		}				
	}
 
	/* wait for child process */
	for (i=0;i<MAX_PROCESS;i++) {
		waitpid(-1,&status,0);
	}
 
	/* sem remove */
	if (sysv_semrm(sem_id) == -1) {
		perror("FAIL: sysv_semrm"); return EXIT_FAILURE;
	}
 
	if (sysv_semrm(full_sem_id) == -1) {
		perror("FAIL: sysv_semrm"); return EXIT_FAILURE;
	}
 
	if (sysv_semrm(empty_sem_id) == -1) {
		perror("FAIL: sysv_semrm"); return EXIT_FAILURE;
	}
 
 
	return 0;	
}
 
/* Name : tfunc_a
 * Desc : action of item product (getting or creation)
 * Argv : void
 * Ret  : void
 */
void tfunc_a()
{
	while(1)
	{
			sysv_semwait(empty_sem_id, 0);		
			sysv_semwait(sem_id, 0);
 
			temp++;
			printf("TFUNC_A] insert %d\n",temp);
 
			sysv_sempost(sem_id, 0);
			sysv_sempost(full_sem_id, 0);		
 
 
 
	}
 
	return;
}
 
/* Name : tfunc_b
 * Desc : action of item consume
 * Argv : void
 * Ret  : void
 */
void tfunc_b()
{
	while(1)
	{
			sysv_semwait(full_sem_id, 0);		
			sysv_semwait(sem_id, 0);
 
			temp++;
			printf("\t\tTFUNC_B] pop %d\n",temp);
 
			sysv_sempost(sem_id, 0);
			sysv_sempost(empty_sem_id, 0);						
	}
 
	return;
}
 
 
/* Name : sysv_shmget
 * Desc : init shared memory (getting or creation)
 * Argv : long key_shm, int n_size (byte), mode(octal notation)
 * Ret  : shm ID (if success), -1 (if fail)
 */
int sysv_shmget(char *tok, key_t shm_fixkey, int size, int user_mode)
{
	key_t	shm_key;
	int	shm_id;
 
	if (tok != NULL) {
		if ((shm_key = ftok(tok, 1234)) == -1) {
			return -1;
		}
	} else {
		shm_key = shm_fixkey;
	}
 
	if ((shm_id = shmget(shm_key, size, IPC_CREAT|user_mode)) == -1) {
		if (errno == EEXIST) { /* already exist shm, just get ipc id */
			shm_id = shmget(shm_key, 0, 0);
		}
	}
	if (shm_id == -1)
		fprintf(stderr,"FAIL: shmget():%s [%s:%d]\n", strerror(errno), __FUNCTION__, __LINE__);
	return shm_id;
}
 
int sysv_shmrm(int shm_id)
{
	int		ret;
	if ((ret = shmctl(shm_id, IPC_RMID, NULL)) == -1) {
		fprintf(stderr,"FAIL: shmctl():%s [%s:%d]\n", 
			strerror(errno), __FUNCTION__, __LINE__);
		return -1;
	}
	return ret;
}
 
/* Name : sysv_semget
 * Desc : init semaphore (getting or creation)
 * Argv : long key_sem, int n_sem, user_mode(octal notation)
 * Ret  : semaphore ID (if success), -1 (if fail)
 */
int sysv_semget(char *tok, key_t sem_fixkey, int n_sem, int sem_value, int user_mode)
{
	int	sem_id, i;
	union semun semun;
	unsigned short int *arr_semval = NULL;
	key_t	sem_key;
 
	/* if tok is not NULL, we make IPC key for semaphore */
	if (tok != NULL) {
		if ((sem_key = ftok(tok, 1234)) == -1) {
			return -1;
		}
	} else {
		sem_key = sem_fixkey;
	}
	if ((sem_id = semget(sem_key, n_sem, IPC_CREAT|IPC_EXCL|user_mode)) == -1) {
		if (errno == EEXIST) {
			/* Is exist ? */
			sem_id = semget(sem_key, n_sem, 0);
			return sem_id;
		}
	}
	if (sem_id == -1) {
		fprintf(stderr,"FAIL: semget [%s:%d]\n", __FUNCTION__, __LINE__);
		return -1;
	}
 
	/* init semaphore value */
	if ((arr_semval = (unsigned short int *)malloc(sizeof(unsigned short int) * n_sem)) == NULL) {
		fprintf(stderr, "FAIL: malloc [%s:%d]\n", __FUNCTION__, __LINE__);
		return -1;
	}
 
	for(i=0; i<n_sem; i++) arr_semval[i] = sem_value;
	semun.array = arr_semval;
	if (semctl(sem_id, 0, SETALL, semun) == -1) {
		fprintf(stderr, "FAIL: semctl [%s:%d]\n", __FUNCTION__, __LINE__);
		if (arr_semval != NULL) free(arr_semval);
		return -1;
	}
	if (arr_semval != NULL) free(arr_semval);
	return sem_id;
}
 
/* Name : sysv_semrm
 * Desc : remove specified semaphore with sem_id
 * Argv : int sem_id
 * Ret  : 0 (if success), -1 (if fail)
 */
int sysv_semrm(int sem_id)
{
	if (semctl(sem_id, 0, IPC_RMID) == -1) {
		fprintf(stderr, "FAIL: semctl() 'IPC_RMID' [%s:%d]\n", __FUNCTION__, __LINE__);
		return -1;
	}
	return 0;
}
 
/* Name : sysv_semwait
 * Desc : P operation about specified SysV semaphore
 * Argv : int sem_id, int sem_idx
 * Ret  : 0 (if success), -1 (if fail)
 */
int sysv_semwait(int _sem_id, int sem_idx)
{
	struct sembuf	sem_buf;
 
	sem_buf.sem_num = sem_idx;
	sem_buf.sem_flg = SEM_UNDO;
	sem_buf.sem_op = -1;
	if (semop(_sem_id, &sem_buf, 1) == -1) {
		fprintf(stderr, "FAIL: semop() 'P' operation [%s:%d]\n", __FUNCTION__, __LINE__);
		getchar();
		return -1;
	}
	return 0;
}
 
/* Name : sysv_sempost
 * Desc : V operation about specified SysV semaphore
 * Argv : int sem_id, int sem_idx
 * Ret  : 0 (if success), -1 (if fail)
 */
int sysv_sempost(int _sem_id, int sem_idx)
{
	struct sembuf	sem_buf;
	sem_buf.sem_num = sem_idx;
	sem_buf.sem_flg = SEM_UNDO;
	sem_buf.sem_op = 1;
	if (semop(_sem_id, &sem_buf, 1) == -1) {
		fprintf(stderr, "FAIL: semop() 'P' operation [%s:%d]\n", __FUNCTION__, __LINE__);
		getchar();
		return -1;
	}
	return 0;
}
 
/* Name : sysv_semval
 * Desc : get specified semaphore value 
 * Argv : int sem_id, int sem_idx
 * Ret  : semaphore value (if success), -1 (if fail)
 */
int sysv_semval(int _sem_id, int sem_idx)
{
	int	semval;
	if ((semval = semctl(_sem_id, sem_idx, GETVAL)) == -1) {
		fprintf(stderr, "FAIL: semctl() 'GETVAL' [%s:%d]\n", __FUNCTION__, __LINE__);
		return -1;
	}
	return semval;
}