#include?“semtest.h“

static?int?comm_sem（?int?numsint?semflag）
{

????key_t?key?=?ftok（SEM_PATHNAMESEM_PROJ_ID）;
????if（key?????{
????????perror（“ftok“）;
????????return?-1;
????}

????int?semid?=?semget（key?nums?semflag）;
????if（semid?????{
????????perror（“semget“）;
????????return?-1;
????}

????return?semid;

}


int?create_sems（int?nums）
{
????return?comm_sem（numsIPC_CREAT|IPC_EXCL|666）;

}

int?get_sems（int?nums）
{
????return?comm_sem（numsIPC_CREAT）;
}

union?semun{
????int?val;
????struct?semid_ds?*buf;
????unsigned?short?*array;
????struct?seminfo?*?__buf;
};


int?init_sems（int?semid?int?which?int?value）
{
????union?semun?_semun;
????_semun.val?=?value;
????int?ret?=?semctl（semidwhichSETVAL_semun）;
????if（ret?????{
????????perror（“init_sem“）;
????????return?-1;
????}
????return?0;

}


int?destory_sems（int?semid）
{

????int?ret?=?semctl（semid0IPC_RMIDNULL）;
????if（ret?<0）
????{
????????perror（“rm_sem“）;
????????return?-1;
????}
????return?0;
}

static?int?comm_sem_op（int?semid?int?which?int?op）
{
????struct?sembuf?_sembuf;
????_sembuf.sem_num?=?which;
????_sembuf.sem_op?=?op;
????_sembuf.sem_flg?=?0;
????return?semop（semid&_sembuf1）;
}

int?P（int?semidint?which）
{
????return?comm_sem_op（semidwhich-1）;
}

int?V（int?semid?int?which）
{
????return?comm_sem_op（semidwhich1）;
}


int?getnums（int?semidint?which）{
????int?ret;
????int?value;
????union?semun?_semun;
????printf（“111?which?===?%d?value?===?%d\n“which_semun.val）;
????ret?=?semctl（semidwhichGETVAL_semun.val）;
????value?=?_semun.val;
????printf（“222?which?===?%d?value?===?%d\n“which_semun.val）;

????return?ret;
}