commit	fa98b4b95e3d184fed296401c220d2a63472c259	[log] [tgz]
author	Marat Dukhan <maratek@gmail.com>	Fri Nov 06 18:19:31 2015 -0500
committer	Marat Dukhan <maratek@gmail.com>	Fri Nov 06 18:19:31 2015 -0500
tree	12f5a28eeb09ba1a1ab991b22c7829dd000d59e3
parent	e76282f42e5f5443dd07ca73452f3eb912e542e7 [diff]

tree: 12f5a28eeb09ba1a1ab991b22c7829dd000d59e3

README.md

pthreadpool

pthreadpool is a pthread-based thread pool implementation. Is 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.
Can be used in Portable Native Client and Native Client environment.
Extensive unit tests based on Google Test.

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;
}