mp_test.c

#include "types.h"
#include "stat.h"
#include "user.h"
#include "thread.h"
#include "cpu_affinity.h"
#include "uthread.h"

__attribute__ ((noinline)) int dribble(int ncount) {
  float neg, a1, a2, a3, a4;
  a1 = 0;
  a2 = 0;
  a3 = 0;
  a4 = 0;
  neg = -1;

  for (int i = 1; i < ncount; i++) {
    a1 += neg + (float)i * 1.0/((2.0*(float)i)-1) + a2;
    a2 += neg + (float)i * 1.0/((2.0*(float)i)-1) + a3;
    a3 += neg + (float)i * 1.0/((2.0*(float)i)-1) + a4;
    a4 += neg + (float)i * 1.0/((2.0*(float)i)-1) + a1;
    neg = -i % 100 - a1;
  }

  return (int) a1 + 1;
}

void task(int idx, int fdwrite) {
//  printf(1, "writing from %d\r\n", idx);

  int out = dribble(1e7);

  write(fdwrite, &out, 1);
}

void *thread_task(int* out) {
//  printf(1, "writing from %d\r\n", *out);

  int out_ = dribble(1e7);

  *out = out_;
  exit();
}

void *thread_task_with_affinity(int* out) {
  cpu_set_t affinity;
  CPU_ZERO(&affinity);
  CPU_SET(0, &affinity);
  sched_setaffinity(&affinity);
  return thread_task(out);
}

int sequential(int ntasks) {
  int fds[2];
  pipe(fds);

  int buf = 0;
  int out = 0;

  for (int idx = 0; idx < ntasks; idx++) {
    task(idx, fds[1]);
  }

  for (int idx = 0; idx < ntasks; idx++) {
    read(fds[0], &buf, 1);
    out += buf;
  }

  return out;
}

int withprocesses(int ntasks) {
  int fds[2];
  pipe(fds);

  int buf = 0;
  int out = 0;

  for (int idx = 0; idx < ntasks; idx++) {
    if (fork() == 0) {
      close(fds[0]);
      task(idx, fds[1]);
      exit();
    }
  }

  for (int idx = 0; idx < ntasks; idx++) {
    if (wait() == -1) {
      printf(1, "We have only %d/%d loyal children\n", idx + 1, ntasks);
      break;
    }

    read(fds[0], &buf, 1);
    out += buf;
  }

  return out;
}

int withthreads(int ntasks) {
  Thread** threads = (Thread**) malloc(sizeof(Thread*) * ntasks);
  int* out = (int*) malloc((sizeof(int)) * ntasks);
  for (int i = 0; i < ntasks; ++i) {
    threads[i] = thread_create(thread_task, &out[i]);
  }

  for (int i = 0; i < ntasks; ++i) {
    thread_join(threads[i]);
  }
  int res = 0;

  for (int i = 0; i < ntasks; ++i) {
    res += out[i];
  }

  return res;
}

int withconcurency(int ntasks) {
  Thread** threads = (Thread**) malloc(sizeof(Thread*) * ntasks);
  int* out = (int*) malloc((sizeof(int)) * ntasks);
  for (int i = 0; i < ntasks; ++i) {
    threads[i] = thread_create(thread_task_with_affinity, &out[i]);
  }

  for (int i = 0; i < ntasks; ++i) {
    thread_join(threads[i]);
  }
  int res = 0;

  for (int i = 0; i < ntasks; ++i) {
    res += out[i];
  }

  return res;
}


void test(UThreadManager *utm, Task* t, int id) {
  printf(1, "test is started, thread id = %d\n", id);
  uthread_yield(utm, t);
  printf(1, "test is working, thread id = %d\n", id);
}


int main() {
//  int starttime, duration;
//  int ntasks = 2;
//
//  {
//    printf(1, "-- With threading :)\n");
//
//    starttime = uptime();
//    int threaded_out = withthreads(ntasks);
//    duration = uptime() - starttime;
//
//    printf(1, "result = %d in %d time units\r\n", threaded_out, duration);
//  }
//
//  {
//    printf(1, "-- With concurrency on 1 CPU :)\n");
//
//    starttime = uptime();
//    int threaded_out = withconcurency(ntasks);
//    duration = uptime() - starttime;
//
//    printf(1, "result = %d in %d time units\r\n", threaded_out, duration);
//  }
//
//  {
//    printf(1, "-- With multiprocessing :)\n");
//
//    starttime = uptime();
//    int multi_out = withprocesses(ntasks);
//    duration = uptime() - starttime;
//
//    printf(1, "result = %d in %d time units\r\n", multi_out, duration);
//  }
//
//  {
//    printf(1, "-- Sequential :(\n");
//
//    starttime = uptime();
//    int seq_out = sequential(ntasks);
//    duration = uptime() - starttime;
//
//    printf(1, "result = %d in %d time units\r\n", seq_out, duration);
//  }

  printf(1, "Started successfully\n");

  int n_workers = 1;
  int n_tasks = 2;
  UThreadManager *utm = uthread_create(n_workers, n_tasks);
  printf(1, "utm.n_run_tasks: %d\n", utm->n_run_tasks);

  uthread_add_task(utm, test, (void*) 0);
  uthread_add_task(utm, test, (void*) 1);

  uthread_join(utm);

  printf(1, "utm.n_run_tasks: %d\n", utm->n_run_tasks);
  printf(1, "Finished successfully\n");

  exit();
}