*** UNIX MANUAL PAGE BROWSER ***

pthread_attr_setscope(3) Library Functions Manual pthread_attr_setscope(3) NAME pthread_attr_setscope - Sets the contention scope attribute of the specified thread attributes object. LIBRARY DECthreads POSIX 1003.1c Library (libpthread.so) SYNOPSIS #include <pthread.h> int pthread_attr_setscope( pthread_attr_t *attr, int scope); STANDARDS Interfaces documented on this reference page conform to industry stan- dards as follows: IEEE Std 1003.1c-1995, POSIX System Application Program Interface PARAMETERS Address of the thread attributes object whose contention scope at- tribute is to be modified. New value for the contention scope at- tribute of the thread attributes object specified by attr. DESCRIPTION This routine uses the value specified in the scope argument to set the contention scope attribute of the thread attributes object specified in the attr argument. The specified attributes object must already be initialized at the time this routine is called. When creating a thread, use a thread attributes object to specify non- default values for thread attributes. The contention scope attribute specifies the set of threads with which a thread must compete for pro- cessing resources. The contention scope attribute specifies whether the new thread competes for processing resources only with other threads in its own process, called <NEWTERM>(process contention scope), or with all threads on the system, called <NEWTERM>(system contention scope). On DIGITAL UNIX, DECthreads supports both process contention scope and system contention scope threads. DECthreads selects at most one thread to execute on each processor at any point in time. DECthreads resolves the contention based on each thread's scheduling attributes (for example, priority) and scheduling policy (for example, round-robin). A thread created using a thread attributes object whose contention scope attribute is set to PTHREAD_SCOPE_PROCESS contends for processing resources with other threads within its own process that also were cre- ated with PTHREAD_SCOPE_PROCESS. It is unspecified how such threads are scheduled relative to threads in other processes or threads in the same process that were created with PTHREAD_SCOPE_SYSTEM contention scope. A thread created using a thread attributes object whose contention scope attribute is set to PTHREAD_SCOPE_SYSTEM contends for processing resources with other threads in any process that also were created with PTHREAD_SCOPE_SYSTEM. NOTES The value of the contention scope attribute of a particular thread at- tributes object does not necessarily correspond to the actual schedul- ing contention scope of any existing thread in your multithreaded pro- gram. RETURN VALUES If an error condition occurs, this routine returns an integer value in- dicating the type of error. Possible return values are as follows: Successful completion. This routine is not supported by the implemen- tation. The value of the attribute being set is not valid. An attempt was made to set the attribute to an unsupported value. ERRORS None RELATED INFORMATION Functions: pthread_attr_destroy(3), pthread_attr_init(3), pthread_attr_getscope(3), pthread_create(3) Manuals: Guide to DECthreads and Programmer's Guide delim off pthread_attr_setscope(3)