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.
- 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.
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;
}