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android / platform / external / pthreadpool / e6be7fc
commite6be7fc5754dfcc62136a712c7dd74d866101450[log] [tgz]
authorMarat Dukhan <maratek@google.com>Mon Sep 30 12:31:21 2019 -0700
committerMarat Dukhan <maratek@google.com>Mon Sep 30 12:31:21 2019 -0700
treeaebabfd994ac531da1ddc001b726c7d572dd2572
parent6673a4c71fe35e077c6843a74017d9c25610c537 [diff]
Minor refactorings

- Extract waiting for new command into a separate function
- Extract allocating memory for the thread pool into a separate function
- Add Google copyright to LICENSE
2 files changed
tree: aebabfd994ac531da1ddc001b726c7d572dd2572
  1. bench/
  2. cmake/
  3. examples/
  4. include/
  5. jni/
  6. src/
  7. test/
  8. .gitignore
  9. .travis.yml
  10. CMakeLists.txt
  11. configure.py
  12. confu.yaml
  13. LICENSE
  14. README.md
README.md

pthreadpool

BSD (2 clause) License Build Status

pthreadpool is a pthread-based thread pool implementation. It is intended to provide functionality of #pragma omp parallel for for POSIX systems where OpenMP is not available.

Features:

  • C interface (C++-compatible).
  • Run on user-specified or auto-detected number of threads.
  • Work-stealing scheduling for efficient work balancing.
  • Compatible with Linux, macOS, and Native Client environments.
  • Covered with unit tests and microbenchmarks.

Example

The following example demonstates using the thread pool for parallel addition of two arrays:

static void add_arrays(struct array_addition_context* context, size_t i) {
  context->sum[i] = context->augend[i] + context->addend[i];
}

#define ARRAY_SIZE 4

int main() {
  double augend[ARRAY_SIZE] = { 1.0, 2.0, 4.0, -5.0 };
  double addend[ARRAY_SIZE] = { 0.25, -1.75, 0.0, 0.5 };
  double sum[ARRAY_SIZE];

  pthreadpool_t threadpool = pthreadpool_create(0);
  assert(threadpool != NULL);
  
  const size_t threads_count = pthreadpool_get_threads_count(threadpool);
  printf("Created thread pool with %zu threads\n", threads_count);

  struct array_addition_context context = { augend, addend, sum };
  pthreadpool_compute_1d(threadpool,
    (pthreadpool_function_1d_t) add_arrays,
    (void**) &context,
    ARRAY_SIZE);
  
  pthreadpool_destroy(threadpool);
  threadpool = NULL;

  printf("%8s\t%.2lf\t%.2lf\t%.2lf\t%.2lf\n", "Augend",
    augend[0], augend[1], augend[2], augend[3]);
  printf("%8s\t%.2lf\t%.2lf\t%.2lf\t%.2lf\n", "Addend",
    addend[0], addend[1], addend[2], addend[3]);
  printf("%8s\t%.2lf\t%.2lf\t%.2lf\t%.2lf\n", "Sum",
    sum[0], sum[1], sum[2], sum[3]);

  return 0;
}