pthread_attr_setscope Subroutine Purpose Sets the value of the contention-scope attribute of a thread attributes object. Library Threads Library (libpthreads.a) Syntax #include
int pthread_attr_setscope (attr, scope) pthread_attr_t *attr; int scope; Description The pthread_attr_setscope subroutine sets the value of the contention-scope attribute of the thread attributes object attr. This attribute specifies the contention scope of a thread created with this attributes object. Note: The pthread.h header file must be the first included file of each source file using the threads library. Parameters attr Specifies the thread attributes object. scope Specifies the contention scope to set. It must have one of the following values: PTHREAD_SCOPE_PROCESS Specifies local contention scope; the thread will be scheduled against other local contention scope threads in the same process. PTHREAD_SCOPE_SYSTEM Specifies global contention scope; the thread will be scheduled against all other threads. This is the default value. Return Values Upon successful completion, 0 is returned. Otherwise, an error code is returned. Error Codes The pthread_attr_setscope subroutine is unsuccessful if the following is true: EINVAL The attr parameter is not valid. ENOSYS The priority scheduling POSIX option is not implemented. ENOTSUP The value of the scope parameter is not supported. Implementation Specifics This subroutine is part of the Base Operating System (BOS) Runtime. The implementation of this subroutine is dependent on the priority scheduling POSIX option. The priority scheduling POSIX option is implemented in AIX, but in the current version all threads have system contention scope; therefore there is no need to use this subroutine, since only the scope value of PTHREAD_SCOPE_SYSTEM is supported. Related Information The pthread_attr_getscope subroutine, pthread_attr_init subroutine, pthread_create subroutine. Threads Scheduling. Threads Library Options and Threads Library Quick Reference.