VMS Help POSIX Threads, PTHREAD routines, pthread_condattr_init, Description *Conan The Librarian (sorry for the slow response - running on an old VAX) |
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.
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