STAPL

1
STAPL
2
STAPL

• Standard Template Adaptive Parallel Library is a
  superset of the C STL
• Emphasizes irregular programs (dynamically linked
  data structures vs arrays, etc)
• SPMD

3
Abstraction Layers

• Interface layer
• Concurrency/Communication layer
• Software Implementation layer
• Machine layer

4
Key Extensions to STL

• Containers -gt pContainers
• Algorithms -gt pAlgorithms
• pRange
• Distributor
• Scheduler
• Executor

5
Extensions

• pContainers are backwards compatible with STL
  containers
• pAlgorithms STAPL includes parallel versions of
  all STL algorithms as well as some other parallel
  operations (parallel prefix)
• pRange construct that allows random access to
  subranges of the data

6
pRanges

• Supports recursive subpartitioning to support
  nested parallelism
• Analogous to STL iterators
• Distributor distributes data
• Scheduler enforces dependences in parallel
  execution according to data dependence graphs
• Contain a relation determining the computation
  order of the subranges and priorities for each.
  If not specified, can be self computed or set to
  specific values for performance reasons

7
pContainers

• Backwards compatible (can provide STL iterators)
• Has internal pRange
• Methods parallelized when possible
• Operation is parallel
• May be called simultaneously be different
  processors in a parallel region

8
pAlgorithms

• Three types
• Semantically identical to STL versions (sort,
  merge, reverse)
• Enhanced semantics (find)
• No counterpart in STL
• Operate on pRanges instead of iterators

9
Runtime System

• Can operate on many platforms
• Can use many systems to implement parallelism
• Pthreads
• OpenMP
• MPI
• Uses parallel memory allocator

10
Using STAPL

• Code can be written directly using pContainers,
  pAlgorithms, pRanges, etc
• Code can be written in STL then translated to use
  STAPL with 5 overhead