Bug: 148971430

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  1. 08bcb15 [automerger skipped] Mark ab/7061308 as merged in stage. am: bf08f8656c -s ours am: 8b446e09b7 -s ours by Xin Li · 11 months ago android-games-sdk-release android-s-v2-preview-1 android12--mainline-release android12-dev android12-qpr1-d-release android12-qpr1-d-s1-release android12-qpr1-d-s2-release android12-qpr1-d-s3-release android12-qpr1-release master android-12.0.0_r16 android-12.0.0_r18 android-12.0.0_r19 android-12.0.0_r20 android-12.0.0_r21 android-12.0.0_r26 android-12.0.0_r27 android-mainline-12.0.0_r4 android-s-v2-beta-2 android-s-v2-preview-2
  2. 8b446e0 [automerger skipped] Mark ab/7061308 as merged in stage. am: bf08f8656c -s ours by Xin Li · 11 months ago
  3. bf08f86 Mark ab/7061308 as merged in stage. by Xin Li · 11 months ago android-s-beta-4 android-s-beta-5 android-s-beta-1 android-s-beta-2 android-s-beta-3
  4. b6ae35c [LSC] Add LOCAL_LICENSE_KINDS to external/pthreadpool am: 3424fb16ee am: ae5409bee6 am: 72716896e4 by Bob Badour · 11 months ago
  5. 7271689 [LSC] Add LOCAL_LICENSE_KINDS to external/pthreadpool am: 3424fb16ee am: ae5409bee6 by Bob Badour · 11 months ago

pthreadpool

BSD (2 clause) License Build Status

pthreadpool is a portable and efficient thread pool implementation. It provides similar functionality to #pragma omp parallel for, but with additional features.

Features:

  • C interface (C++-compatible).
  • 1D-6D loops with step parameters.
  • Run on user-specified or auto-detected number of threads.
  • Work-stealing scheduling for efficient work balancing.
  • Wait-free synchronization of work items.
  • Compatible with Linux (including Android), macOS, iOS, Windows, Emscripten environments.
  • 100% unit tests coverage.
  • Throughput and latency 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_parallelize_1d(threadpool,
    (pthreadpool_task_1d_t) add_arrays,
    (void*) &context,
    ARRAY_SIZE,
    PTHREADPOOL_FLAG_DISABLE_DENORMALS /* flags */);

  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;
}