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POSIX Threads, PTHREAD routines, pthread_condattr_init
*Conan The Librarian (sorry for the slow response - running on an old VAX)
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Initializes a condition variable attributes object.
#include <pthread.h>
int
pthread_condattr_init (
pthread_condattr_t *attr);
attr
Address of the condition variable attributes object to be
initialized.
This routine initializes the condition variable attributes object
specified by the attr argument with a set of default attribute
values.
When an attributes object is used to create a condition
variable, the values of the individual attributes determine the
characteristics of the new condition variable. Attributes objects
act as additional arguments to condition variable creation.
Changing individual attributes in an attributes object does not
affect any condition variables that were previously created using
that attributes object.
You can use the same condition variable attributes object in
successive calls to pthread_condattr_init(), from any thread.
If multiple threads can change attributes in a shared attributes
object, your program must use a mutex to protect the integrity of
that attributes object.
Results are undefined if this routine is called and the attr
argument specifies a condition variable attributes object that is
already initialized.
Currently, on OpenVMS systems, no attributes affecting condition
variables are defined; you cannot change any attributes in the
condition variable attributes object. On Tru64 UNIX systems, the
PSHARED attribute is defined.
The pthread_condattr_init() and pthread_condattr_destroy()
routines are provided for future expandability of the pthread
interface and to conform with the POSIX.1 standard. These
routines serve no useful function, because there are no pthread_
condattr_set*() type routines available at this time.
If an error condition occurs, this routine returns an integer
value indicating the type of error. Possible return values are as
follows:
Return Description
0 Successful completion.
[EINVAL] The value specified by attr is not a valid condition
variable attributes object.
[ENOMEM] Insufficient memory exists to initialize the
condition variable attributes object.
pthread_condattr_destroy()
pthread_cond_init()
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