openmp-tutorial

IWOMP 20051An Introduction In to OpenMPRuud van der PasSenior Staff EngineerScalable Systems GroupSun MicrosystemsIWOMP 2005University of OregonEugene, Oregon, USAJune 1-4, 2005An Introduction Into OpenMP Copyright©2005 Sun MicrosystemsRvdP/V1.1IWOMP 2005Outline2❑The OpenMP Programming Model❑OpenMP Guided Tour❑OpenMP Overview● C lauses● Worksharing constructs● Synchronization constructs● Environment variables● Global Data● Runtime functions❑Wrap-upAn Introduction Into OpenMP Copyright©2005 Sun MicrosystemsRvdP/V1.1IWOMP 20053The OpenMP Programming ModelAn Introduction Into OpenMP Copyright©2005 Sun MicrosystemsRvdP/V1.1IWOMP 20054Memory0 1 PAn Introduction Into OpenMP Copyright©2005 Sun MicrosystemsRvdP/V1.1IWOMP 2005Shared Memory Model5Programming ModelTT✔All threads have access to the privatesame, globally shared, privatememory✔Data can be shared or privateShared ✔Shared data is accessible by Memory all threadsT✔Private data can be accessed private only by the threads that owns private itT T ✔Data transfer is transparent to the programmerprivate✔Synchronization takes place, but it is mostly implicitAn Introduction Into OpenMP Copyright©2005 Sun MicrosystemsRvdP/V1.1IWOMP 2005About Data6In a shared memory parallel program variables have a "label" attached to them:☞L abelled "Private" ⇨ Visible to one thread only✔C hange made in local data, is not seen by others✔Example - L ocal variables in a function that is ...