问使用线程条件变量的死锁程序，关键部分[C++]

EN

#include <iostream>
#include <pthread.h>

using namespace std;

struct foo
{
public:
   int var;
   int *turn;
   int index;
   pthread_mutex_t *bsem;
   pthread_cond_t *waitTurn;
};
void *threadFunc(void *arg) {
    int var;
    foo *workingVar = (foo *)arg;
    pthread_mutex_lock(workingVar->bsem);
    while (*workingVar->turn != workingVar->index)
        pthread_cond_wait(workingVar->waitTurn, workingVar->bsem);
    var = workingVar->var;
    *workingVar->turn++;
    pthread_cond_broadcast(workingVar->waitTurn);
    pthread_mutex_unlock(workingVar->bsem);
    cout << var << endl;
    return nullptr;
}
int main() {
   int turn = 0, NTHREADS = 5;
   foo mainStruct;
   pthread_mutex_t bsem;
   pthread_mutex_init(&bsem, NULL);
   pthread_cond_t waitTurn = PTHREAD_COND_INITIALIZER;
   mainStruct.bsem = &bsem;
   mainStruct.waitTurn = &waitTurn;
   mainStruct.turn = &turn;
   pthread_t tid[NTHREADS];
   for (int i = 0; i < NTHREADS; i++) {
   mainStruct.index = i;
   mainStruct.var = i;
   pthread_create(&tid[i], nullptr, threadFunc, &mainStruct);
   }
   for (int i = 0; i < NTHREADS; i++)
      pthread_join(tid[i], NULL);
}