#ifndef _XOPEN_SOURCE

#define _XOPEN_SOURCE 700

#endif

#include <errno.h>

#include <stdlib.h>

#include <string.h>

#include <time.h>

#include <sys/types.h>

#include <sys/sem.h>

#include <sys/wait.h>

#include <unistd.h>

#include "test.h"

static const char path[] = ".";

static const int id = 's';

#define T(f) do{ \

	if ((f)+1 == 0) \

		t_error("%s failed: %s\n", #f, strerror(errno)); \

}while(0)

#define EQ(a,b,fmt) do{ \

	if ((a) != (b)) \

		t_error("%s == %s failed: " fmt "\n", #a, #b, a, b); \

}while(0)

static void inc()

{

	time_t t;

	key_t k;

	int semid, semval, sempid, semncnt, semzcnt;

	struct semid_ds semid_ds;

	union semun {

		int val;

		struct semid_ds *buf;

		unsigned short *array;

	} arg;

	struct sembuf sops;

	T(t = time(0));

	T(k = ftok(path, id));

	/* make sure we get a clean semaphore id */

	T(semid = semget(k, 1, IPC_CREAT|0666));

	T(semctl(semid, 0, IPC_RMID));

	T(semid = semget(k, 1, IPC_CREAT|IPC_EXCL|0666));

	if (t_status)

		exit(t_status);

	/* check IPC_EXCL */

	errno = 0;

	if (semget(k, 1, IPC_CREAT|IPC_EXCL|0666) != -1 || errno != EEXIST)

		t_error("semget(IPC_CREAT|IPC_EXCL) should have failed with EEXIST, got %s\n", strerror(errno));

	/* check if msgget initilaized the msqid_ds structure correctly */

	arg.buf = &semid_ds;

	T(semctl(semid, 0, IPC_STAT, arg));

	EQ(semid_ds.sem_perm.cuid, geteuid(), "got %d, want %d");

	EQ(semid_ds.sem_perm.uid, geteuid(), "got %d, want %d");

	EQ(semid_ds.sem_perm.cgid, getegid(), "got %d, want %d");

	EQ(semid_ds.sem_perm.gid, getegid(), "got %d, want %d");

	EQ(semid_ds.sem_perm.mode & 0x1ff, 0666, "got %o, want %o");

	EQ(semid_ds.sem_nsems, 1, "got %d, want %d");

	EQ((long long)semid_ds.sem_otime, 0, "got %lld, want %d");

	if (semid_ds.sem_ctime < t)

		t_error("semid_ds.sem_ctime >= t failed: got %lld, want >= %lld\n", (long long)semid_ds.sem_ctime, (long long)t);

	if (semid_ds.sem_ctime > t+5)

		t_error("semid_ds.sem_ctime <= t+5 failed: got %lld, want <= %lld\n", (long long)semid_ds.sem_ctime, (long long)t+5);

	/* test sem_op > 0 */

	sops.sem_num = 0;

	sops.sem_op = 1;

	sops.sem_flg = 0;

	T(semop(semid, &sops, 1));

	T(semval = semctl(semid, 0, GETVAL));

	EQ(semval, 1, "got %d, want %d");

	T(sempid = semctl(semid, 0, GETPID));

	EQ(sempid, getpid(), "got %d, want %d");

	T(semncnt = semctl(semid, 0, GETNCNT));

	EQ(semncnt, 0, "got %d, want %d");

	T(semzcnt = semctl(semid, 0, GETZCNT));

	EQ(semzcnt, 0, "got %d, want %d");

}

static void dec()

{

	key_t k;

	int semid, semval;

	struct sembuf sops;

	T(k = ftok(path, id));

	T(semid = semget(k, 0, 0));

	/* test sem_op < 0 */

	sops.sem_num = 0;

	sops.sem_op = -1;

	sops.sem_flg = 0;

	T(semop(semid, &sops, 1));

	T(semval = semctl(semid, 0, GETVAL));

	EQ(semval, 0, "got %d, want %d");

	/* cleanup */

	T(semctl(semid, 0, IPC_RMID));

}

int main(void)

{

	int p;

	int status;

	inc();

	p = fork();

	if (p == -1)

		t_error("fork failed: %s\n", strerror(errno));

	else if (p == 0)

		dec();

	else {

		T(waitpid(p, &status, 0));

		if (!WIFEXITED(status) || WEXITSTATUS(status) != 0)

			t_error("child exit status: %d\n", status);

	}

	return t_status;

}