PTHREAD_CONDATTR_GETPSHARED(3C) Standard C Library Functions

NAME

pthread_condattr_getpshared, pthread_condattr_setpshared - get or set
process-shared condition variable attributes

SYNOPSIS

cc -mt [ flag... ] file... -lpthread [ library... ]
#include <pthread.h>

int pthread_condattr_getpshared(
const pthread_condattr_t *restrict attr,
int *restrict pshared);


int pthread_condattr_setpshared(pthread_condattr_t *attr,
int pshared);

DESCRIPTION

The pthread_condattr_getpshared() function obtains the value of the
process-shared attribute from the attributes object referenced by attr.
The pthread_condattr_setpshared() function is used to set the process-
shared attribute in an initialized attributes object referenced by attr.


The process-shared attribute is set to PTHREAD_PROCESS_SHARED to permit
a condition variable to be operated upon by any thread that has access to
the memory where the condition variable is allocated, even if the
condition variable is allocated in memory that is shared by multiple
processes. If the process-shared attribute is PTHREAD_PROCESS_PRIVATE,
the condition variable will only be operated upon by threads created
within the same process as the thread that initialized the condition
variable; if threads of differing processes attempt to operate on such a
condition variable, the behavior is undefined. The default value of the
attribute is PTHREAD_PROCESS_PRIVATE.


Additional attributes, their default values, and the names of the
associated functions to get and set those attribute values are
implementation-dependent.

RETURN VALUES

If successful, the pthread_condattr_setpshared() function returns 0.
Otherwise, an error number is returned to indicate the error.


If successful, the pthread_condattr_getpshared() function returns 0 and
stores the value of the process-shared attribute of attr into the object
referenced by the pshared parameter. Otherwise, an error number is
returned to indicate the error.

ERRORS

The pthread_condattr_getpshared() and pthread_condattr_setpshared()
functions may fail if:

EINVAL
The value specified by attr is invalid.


The pthread_condattr_setpshared() function will fail if:

EINVAL
The new value specified for the attribute is outside the range
of legal values for that attribute.

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:


+--------------------+-----------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-----------------+
|Interface Stability | Standard |
+--------------------+-----------------+
|MT-Level | MT-Safe |
+--------------------+-----------------+

SEE ALSO

pthread_cond_init(3C), pthread_condattr_init(3C), pthread_create(3C),
pthread_mutex_init(3C), attributes(7), standards(7)


March 23, 2005 PTHREAD_CONDATTR_GETPSHARED(3C)