12. Condition Variable Manager¶

12.1. Introduction¶

The condition variable manager …

The directives provided by the condition variable manager are:

pthread_condattr_init - Initialize a Condition Variable Attribute Set
pthread_condattr_destroy - Destroy a Condition Variable Attribute Set
pthread_condattr_setpshared - Set Process Shared Attribute
pthread_condattr_getpshared - Get Process Shared Attribute
pthread_cond_init - Initialize a Condition Variable
pthread_cond_destroy - Destroy a Condition Variable
pthread_cond_signal - Signal a Condition Variable
pthread_cond_broadcast - Broadcast a Condition Variable
pthread_cond_wait - Wait on a Condition Variable
pthread_cond_timedwait - With with Timeout a Condition Variable

12.2. Background¶

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12.3. Operations¶

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12.4. Directives¶

This section details the condition variable manager’s directives. A subsection is dedicated to each of this manager’s directives and describes the calling sequence, related constants, usage, and status codes.

12.4.1. pthread_condattr_init - Initialize a Condition Variable Attribute Set¶

CALLING SEQUENCE:

#include <pthread.h>
int pthread_condattr_init(
    pthread_condattr_t *attr
);

STATUS CODES:

ENOMEM

Insufficient memory is available to initialize the condition variable attributes object.

DESCRIPTION:

NOTES:

12.4.2. pthread_condattr_destroy - Destroy a Condition Variable Attribute Set¶

CALLING SEQUENCE:

#include <pthread.h>
int pthread_condattr_destroy(
    pthread_condattr_t *attr
);

STATUS CODES:

EINVAL

The attribute object specified is invalid.

DESCRIPTION:

NOTES:

12.4.3. pthread_condattr_setpshared - Set Process Shared Attribute¶

CALLING SEQUENCE:

#include <pthread.h>
int pthread_condattr_setpshared(
    pthread_condattr_t *attr,
    int                 pshared
);

STATUS CODES:

EINVAL

Invalid argument passed.

DESCRIPTION:

NOTES:

12.4.4. pthread_condattr_getpshared - Get Process Shared Attribute¶

CALLING SEQUENCE:

#include <pthread.h>
int pthread_condattr_getpshared(
    const pthread_condattr_t *attr,
    int                      *pshared
);

STATUS CODES:

EINVAL

Invalid argument passed.

DESCRIPTION:

NOTES:

12.4.5. pthread_cond_init - Initialize a Condition Variable¶

CALLING SEQUENCE:

#include <pthread.h>
int pthread_cond_init(
    pthread_cond_t           *cond,
    const pthread_condattr_t *attr
);

STATUS CODES:

`EAGAIN`	The system lacked a resource other than memory necessary to create the initialize the condition variable object.
`ENOMEM`	Insufficient memory is available to initialize the condition variable object.
`EBUSY`	The specified condition variable has already been initialized.
`EINVAL`	The specified attribute value is invalid.

DESCRIPTION:

NOTES:

12.4.6. pthread_cond_destroy - Destroy a Condition Variable¶

CALLING SEQUENCE:

#include <pthread.h>
int pthread_cond_destroy(
    pthread_cond_t *cond
);

STATUS CODES:

`EINVAL`	The specified condition variable is invalid.
`EBUSY`	The specified condition variable is currently in use.

DESCRIPTION:

NOTES:

12.4.7. pthread_cond_signal - Signal a Condition Variable¶

CALLING SEQUENCE:

#include <pthread.h>
int pthread_cond_signal(
    pthread_cond_t *cond
);

STATUS CODES:

EINVAL

The specified condition variable is not valid.

DESCRIPTION:

NOTES:

This routine should not be invoked from a handler from an asynchronous signal handler or an interrupt service routine.

12.4.8. pthread_cond_broadcast - Broadcast a Condition Variable¶

CALLING SEQUENCE:

#include <pthread.h>
int pthread_cond_broadcast(
    pthread_cond_t *cond
);

STATUS CODES:

EINVAL

The specified condition variable is not valid.

DESCRIPTION:

NOTES:

This routine should not be invoked from a handler from an asynchronous signal handler or an interrupt service routine.

12.4.9. pthread_cond_wait - Wait on a Condition Variable¶

CALLING SEQUENCE:

#include <pthread.h>
int pthread_cond_wait(
    pthread_cond_t *cond,
    pthread_mutex_t *mutex
);

STATUS CODES:

EINVAL

The specified condition variable or mutex is not initialized OR different mutexes were specified for concurrent pthread_cond_wait() and pthread_cond_timedwait() operations on the same condition variable OR the mutex was not owned by the current thread at the time of the call.

DESCRIPTION:

NOTES:

12.4.10. pthread_cond_timedwait - Wait with Timeout a Condition Variable¶

CALLING SEQUENCE:

#include <pthread.h>
int pthread_cond_timedwait(
    pthread_cond_t        *cond,
    pthread_mutex_t       *mutex,
    const struct timespec *abstime
);

STATUS CODES:

`EINVAL`	The nanoseconds field of timeout is invalid.
`EINVAL`	The specified condition variable or mutex is not initialized OR different mutexes were specified for concurrent `pthread_cond_wait()` and `pthread_cond_timedwait()` operations on the same condition variable OR the mutex was not owned by the current thread at the time of the call.
`ETIMEDOUT`	The specified time has elapsed without the condition variable being satisfied.

DESCRIPTION:

NOTES: