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#include <stdio.h>
#include <threads.h>

enum { NTHREADS = 5 };

mtx_t mutex;
cnd_t cond;

int run_step(void *t) {
  static int current_step = 0;
  size_t my_step = *(size_t *)t;

  if (thrd_success != mtx_lock(&mutex)) {
    /* Handle error */
  }

  printf("Thread %d%zu has the lock\n", my_step);
  while (current_step != my_step) {
    printf("Thread %d%zu is sleeping...\n", my_step);

    if (thrd_success != cnd_wait(&cond, &mutex)) {
      /* Handle error */
    }

    printf("Thread %d%zu woke up\n", my_step);
  }
  /* Do processing ... */
  printf("Thread %d%zu is processing...\n", my_step);
  current_step++;

  /* Signal awaiting task */
  if (thrd_success != cnd_signal(&cond)) {
    /* Handle error */
  }

  printf("Thread %d%zu is exiting...\n", my_step);

  if (thrd_success != mtx_unlock(&mutex)) {
    /* Handle error */
  }
  return 0;
}
int main(void) {
  thrd_t threads[NTHREADS];
  size_t step[NTHREADS];

  if (thrd_success != mtx_init(&mutex, mtx_plain)) {
    /* Handle error */
  }

  if (thrd_success != cnd_init(&cond)) {
    /* Handle error */
  }

  /* Create threads */
  for (size_t i = 0; i < NTHREADS; ++i) {
    step[i] = i;

  if (thrd_success != thrd_create(&threads[i], run_step,
                                  &step[i])) {
    /* Handle error */
  }
}

  /* Wait for all threads to complete */
  for (size_t i = NTHREADS; i != 0; --i) {
    if (thrd_success != thrd_join(threads[i-1], NULL)) {
      /* Handle error */
    }
  }

  mtx_destroy(&mutex);
  cnd_destroy(&cond);
  return 0;
} 

#include <stdio.h>
#include <threads.h>

mtx_t mutex;
cnd_t cond;
int run_step(void *t) {
  static size_t current_step = 0;
  size_t my_step = *(size_t *)t;

  if (thrd_success != mtx_lock(&mutex)) {
    /* Handle error */
  }

  printf("Thread %d%zu has the lock\n", my_step);

  while (current_step != my_step) {
    printf("Thread %d%zu is sleeping...\n", my_step);

    if (thrd_success != cnd_wait(&cond, &mutex)) {
      /* Handle error */
    }

  printf("Thread %d%zu woke up\n", my_step);
  }

  /* Do processing ... */
  printf("Thread %d%zu is processing...\n", my_step);

  current_step++;

  /* Signal ALL waiting tasks */
  if (thrd_success != cnd_broadcast(&cond)) {
    /* Handle error */
  }

  printf("Thread %d%zu is exiting...\n", my_step);

  if (thrd_success != mtx_unlock(&mutex)) {
    /* Handle error */
  }
  return 0;
}

#include <stdio.h>
#include <threads.h>

enum { NTHREADS = 5 };

mtx_t mutex;
cnd_t cond[NTHREADS];

int run_step(void *t) {
  static size_t current_step = 0;
  size_t my_step = *(size_t *)t;

  if (thrd_success != mtx_lock(&mutex)) {
    /* Handle error */
  }

  printf("Thread %d%zu has the lock\n", my_step);

  while (current_step != my_step) {
    printf("Thread %d%zu is sleeping...\n", my_step);

    if (thrd_success != cnd_wait(&cond[my_step], &mutex)) {
      /* Handle error */
    }

    printf("Thread %d%zu woke up\n", my_step);
  }

  /* Do processing ... */
  printf("Thread %d%zu is processing...\n", my_step);

  current_step++;

  /* Signal next step thread */
  if ((my_step + 1) < NTHREADS) {
    if (thrd_success != cnd_signal(&cond[my_step + 1])) {
      /* Handle error */
    }
  }

  printf("Thread %d%zu is exiting...\n", my_step);

  if (thrd_success != mtx_unlock(&mutex)) {
    /* Handle error */
  }
  return 0;
}

int main(void) {
  thrd_t threads[NTHREADS];
  size_t step[NTHREADS];

  if (thrd_success != mtx_init(&mutex, mtx_plain)) {
    /* Handle error */
  }

  for (size_t i = 0; i< NTHREADS; ++i) {
    if (thrd_success != cnd_init(&cond[i])) {
      /* Handle error */
    }
  }

  /* Create threads */
  for (size_t i = 0; i < NTHREADS; ++i) {
    step[i] = i;
    if (thrd_success != thrd_create(&threads[i], run_step,
                                    &step[i])) {
      /* Handle error */
    }
  }

  /* Wait for all threads to complete */
  for (size_t i = NTHREADS; i != 0; --i) {
    if (thrd_success != thrd_join(threads[i-1], NULL)) {
      /* Handle error */
    }
  }

  mtx_destroy(&mutex);

  for (size_t i = 0; i < NTHREADS; ++i) {
    cnd_destroy(&cond[i]);
  }
  return 0;
}

#include <Windows.h>
#include <stdio.h>
 
CRITICAL_SECTION lock;
CONDITION_VARIABLE cond;
 
DWORD WINAPI run_step(LPVOID t) {
  static size_t current_step = 0;
  size_t my_step = (size_t)t;

  EnterCriticalSection(&lock);  
  printf("Thread %d%zu has the lock\n", my_step);

  while (current_step != my_step) {
    printf("Thread %d%zu is sleeping...\n", my_step);
 
    if (!SleepConditionVariableCS(&cond, &lock, INFINITE)) {
      /* Handle error */
    }

    printf("Thread %d%zu woke up\n", my_step);
  }

  /* Do processing ... */
  printf("Thread %d%zu is processing...\n", my_step);

  current_step++;
 
  LeaveCriticalSection(&lock);
 
  /* Signal ALL waiting tasks */
  WakeAllConditionVariable(&cond);
 
  printf("Thread %d%zu is exiting...\n", my_step);
  return 0;
}
 
enum { NTHREADS = 5 };
 
int main(void) {
  HANDLE threads[NTHREADS];
  
  InitializeCriticalSection(&lock);
  InitializeConditionVariable(&cond);
 
  /* Create threads */
  for (size_t i = 0; i < NTHREADS; ++i) {
    threads[i] = CreateThread(NULL, 0, run_step, (LPVOID)i, 0, NULL);
  }
 
  /* Wait for all threads to complete */
  WaitForMultipleObjects(NTHREADS, threads, TRUE, INFINITE);
 
  DeleteCriticalSection(&lock);
 
  return 0;
}