semaphores

semaphore information 

Realtime Information


SYNOPSIS

#include <semaphore.h>


DESCRIPTION

The <semaphore.h> header file is designed for use with semaphore operations. This header file defines the sem_t type, used in performing semaphore operations.

The SEM_FAILED symbol is also defined (see sem_open()).

The following are declared as functions:

int    sem_close(sem_t *);
int    sem_destroy(sem_t *);
int    sem_getvalue(sem_t *, int *);
int    sem_init(sem_t *, int, unsigned int);
sem_t *sem_open(const char *, int, ...);
int    sem_post(sem_t *);
int    sem_trywait(sem_t *);
int    sem_unlink(const char *);
int    sem_wait(sem_t *);

Inclusion of the <semaphore.h> header makes visible symbols defined in the headers <fcntl.h> and <sys/types.h>.

Additionally, the following semaphore-related symbols are defined in the <limits> header file:

_POSIX_SEM_NSEMS_MAX 

Specifies the maximum number of semaphores. By default, this is 255, but it can be overridden by changing the value in the Max Number of Semaphores field in the Semaphore Settings category on the Runtime Settings tab of the MKS Toolkit control panel applet.

_POSIX_SEM_VALUE_MAX 

Specifies the maximum value for use when initializing a semaphore.


CONFORMANCE

UNIX 03.


MULTITHREAD SAFETY LEVEL

MT-Safe.


PORTING ISSUES

None.


AVAILABILITY

PTC MKS Toolkit for Professional Developers
PTC MKS Toolkit for Professional Developers 64-Bit Edition
PTC MKS Toolkit for Enterprise Developers
PTC MKS Toolkit for Enterprise Developers 64-Bit Edition


SEE ALSO

Functions:
sem_close(), sem_destroy(), sem_getvalue(), sem_init(), sem_open(), sem_post(), sem_timedwait(), sem_unlink(), sem_wait()


PTC MKS Toolkit 10.3 Documentation Build 39.