#include <semaphore.h>
#include <qlg.h>
sem_t * QlgSem_open_np(const Qlg_Path_Name_T *name, int oflag
mode_t mode, unsigned int value,
sem_attr_np_t * attr);
The QlgSem_open_np() function, like the sem_open_np() function, opens a named semaphore and returns a semaphore pointer that may be used on subsequent calls to sem_post(), sem_post_np(), sem_wait(), sem_wait_np(), sem_trywait(), sem_getvalue(), and sem_close(). The QlgSem_open_np() function takes a pointer to a Qlg_Path_Name_T structure, while the sem_open_np() function takes a pointer to a character string.
Limited information on the name parameter is provided in this API. For additional information on the name parameter and a discussion of other parameters, authorities required, return values, and related information, see sem_open_np()--Open Named Semaphore with Maximum Value.
If QlgSem_open_np() is not successful, errno usually indicates the following error or one of the errors identified in sem_open_np()--Open Named Semaphore with Maximum Value.
Note: All of the related information for sem_open_np() applies to QlgSem_open_np(). See Related Information in sem_open().
See Code disclaimer information for information pertaining to code examples.
The following example opens the named semaphore "/mysemaphore" and creates the semaphore with an initial value of 10 and a maxiumum value of 11. The permissions are set such that only the current user has access to the semaphore.
#include <semaphore.h>
#include <qlg.h>
main() {
sem_t * my_semaphore;
int rc;
sem_attr_np_t attr;
#define mypath "/mysemaphore"
const char US_const[3]= "US";
const char Language_const[4]="ENU";
const char Path_Name_Del_const[2]= "/";
typedef struct pnstruct
{
Qlg_Path_Name_T qlg_struct;
char[100] pn; /* This size must be >= the path */
/* name length or be a pointer */
/* to the path name. */
};
struct pnstruct path;
/***************************************************************/
/* Initialize Qlg_Path_Name_T parameters */
/***************************************************************/
memset((void*)path name, 0x00, sizeof(struct pnstruct));
path.qlg_struct.CCSID = 37;
memcpy(path.qlg_struct.Country_ID,US_const,2);
memcpy(path.qlg_struct.Language_ID,Language_const,3);
path.qlg_struct.Path_Type = QLG_CHAR_SINGLE;
path.qlg_struct.Path_Length = sizeof(mypath)-1;
memcpy(path.qlg_struct.Path_Name_Delimiter,Path_Name_Del_const,1);
memcpy(path.pn,mypath,sizeof(mypath));
memset(&attr, 0, sizeof(attr));
attr.maxvalue=11;
my_semaphore = QlgSem_open_np((Qlg_Path_Name_T *)path name,
O_CREAT|O_EXCL,
S_IRUSR | S_IWUSR,
10,
&attr);
}
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