/*
clang -o wait2 wait2.c -Wall -g;./wait2&p=$!;sleep 0.1;kill -USR1 $p;wait $p
[1] 3574450
signal
110=Connection timed out
[1]+  Exit 1                  ./wait2
*/
#define _GNU_SOURCE
#include <pthread.h>
#include <assert.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <signal.h>
#include <sys/time.h>
static void sig(int signo) {
  puts("signal");
}
int main(void) {
  setbuf(stdout,NULL);
  struct sigaction sa;
  memset(&sa,0,sizeof(sa));
  sa.sa_handler=sig;
  int err;
  err=sigaction(SIGUSR1,&sa,NULL);
  assert(!err);
//  pthread_mutex_t mut = PTHREAD_MUTEX_INITIALIZER; // not reproducible
  pthread_mutex_t mut = PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP;
  pthread_cond_t cond = PTHREAD_COND_INITIALIZER;
  err=pthread_mutex_lock(&mut);
  assert(!err);
  struct timeval tv;
  err=gettimeofday(&tv,NULL/*tz*/);
  assert(!err);
  struct timespec ts;
  ts.tv_sec=tv.tv_sec;
  ts.tv_nsec=tv.tv_usec*1000;
  ts.tv_sec++;
  err=pthread_cond_timedwait(&cond, &mut, &ts);
  if (err) {
    printf("%d=%s\n",err,strerror(err));
    return 1;
  }
  return 0;
}