pthread_condattr_getpshared.3t (2010 09)

p
pthread_condattr_getpshared(3T) pthread_condattr_getpshared(3T)
(Pthread Library)
NAME
pthread_condattr_getpshared(), pthread_condattr_setpshared() - get or set the process-shared attribute
SYNOPSIS
#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
);
PARAMETERS
attr Pointer to the condition variable attributes object whose process-shared attribute is to be
set/retrieved.
pshared This parameter either specifies the new value of the process-shared attribute (set func-
tion) or it points to the memory location where the process-shared attribute of attr is to be
returned (get function).
DESCRIPTION
The attributes object attr must have been previously initialized with the function
pthread_condattr_init()
before these functions are called.
The functions are used to set and retrieve the process-shared attribute in a condition variable attributes
object. The legal values for the process-shared attribute are:
PTHREAD_PROCESS_SHARED
This option permits a condition variable to be operated upon by any thread that has access to
the memory where the condition variable is allocated. The application is responsible for allo-
cating the condition variable in memory that multiple processes can access.
PTHREAD_PROCESS_PRIVATE
The condition variable can be operated on only 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 condition variable, the behavior is undefined.
The default value of process-shared is
PTHREAD_PROCESS_PRIVATE.
pthread_condattr_setpshared()
sets the process-shared attribute in attr . The new value of the
process-shared attribute of attr is set to the value specified in the pshared parameter.
pthread_condattr_getpshared()
retrieves the value of the process-shared attribute from attr .
The value of the process-shared attribute of attr is returned in the pshared parameter.
RETURN VALUE
Upon successful completion,
pthread_condattr_getpshared() and
pthread_condattr_setpshared() return zero. Otherwise, an error number is returned to indi-
cate the error (the errno variable is not set).
ERRORS
If any of the following occur, the
pthread_condattr_getpshared()
and
pthread_condattr_setpshared() functions return the corresponding error number:
[ENOSYS]
_POSIX_THREAD_PROCESS_SHARED is not defined and these functions are not
supported.
For each of the following conditions, if the condition is detected, the
pthread_condattr_setpshared() function returns the corresponding error number:
[EINVAL] attr is not a valid condition variable attributes object.
[EINVAL] The value specified by pshared is not a legal value.
For each of the following conditions, if the condition is detected, the
pthread_condattr_getpshared() function returns the corresponding error number:
HP-UX 11i Version 3: September 2010 − 1 − Hewlett-Packard Company 1