关于用采用单独的线程对信号进行处理的问题
代码：
#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <pthread.h>
#include <apue.h>

int anaFlag = 0; //The flag of analysis
sigset_t mask;
pthread_mutex_t anaFlag_lock = PTHREAD_MUTEX_INITIALIZER;
pthread_cond_t anaFlag_signal = PTHREAD_COND_INITIALIZER;

void *
sig_handler(void *arg)
{
int err, signo;
for (;;) {
err = sigwait(&mask, &signo);
if (err != 0)
err_exit(err, "sigwait failed");
switch (signo) {
case SIGUSR1:
pthread_mutex_lock(&anaFlag_lock);
anaFlag = 1;
pthread_mutex_unlock(&anaFlag_lock);
pthread_cond_signal(&anaFlag_signal);
break;
case SIGUSR2:
pthread_mutex_lock(&anaFlag_lock);
anaFlag = 0;
pthread_mutex_lock(&anaFlag_lock);
pthread_cond_signal(&anaFlag_signal);
break;
default:
err_sys("unexpected signal %d\n", signo);
}
}
}

int
main(void)
{
  int ret;
  pthread_t signalTid;

  sigemptyset(&mask);
sigaddset(&mask, SIGUSR1);
sigaddset(&mask, SIGUSR2);
if ((ret = pthread_sigmask(SIG_BLOCK, &mask, NULL)) != 0)
err_exit(ret, "SIG_BLOCK error");
if ((ret = pthread_create(&signalTid, NULL, sig_handler, 0)) != 0)
err_exit(ret, "can't create thread");

  pthread_mutex_lock(&anaFlag_lock);
printf("befor analysis, wait signal, anaFlag=%d\n", anaFlag);
while (anaFlag == 0)
pthread_cond_wait(&anaFlag_signal, &anaFlag_lock);
pthread_mutex_unlock(&anaFlag_lock);

  /* analyse something... */
  printf("analysis start, anaFlag=%d\n",anaFlag);
  // analyse();

  pthread_mutex_lock(&anaFlag_lock);
while (anaFlag == 1){
pthread_cond_wait(&anaFlag_signal, &anaFlag_lock);
}
pthread_mutex_unlock(&anaFlag_lock);

  /* after analysis */
  printf("after analysis, wait signal, anaFlag=%d\n",anaFlag);
  // stopAnalyse();

  /* deal with the result ... */
   
  exit(0);
}

程序想实现的功能是：当程序接收到SIGUSR1信号时，启动analysis过程，当收到SIGUSR2时，停止analysis过程。线程signalTid负责 处理 SIGUSR1 和 SIGUSR2 信号。
可程序的实际运行结果是：程序能接收到SIGUSR1信号，并启动analysis过程,能收到SIGUSR2信号，但主线程却停在“pthread_cond_wait(&anaFlag_signal, &anaFlag_lock);”，并不能收到sig_handler发过来的信号“pthread_cond_signal(&anaFlag_signal);”。

哪位大虾知道这是为什么啊？能否解答下，谢谢！！
   




------解决方案--------------------
代码太乱没心思看，你的目的用pthread_sigmask就可以实现，不想处理信号的线程block所有的信号，处理信号的线程不block信号就可以。