在unix的多进程编程中，僵尸进程的产生往往都是父进程没有处理SIGCHLD信号而引起的，我这里特别用ACE写了一个产生僵尸进程及其如何处理的用例。可以作为参考：程序循环启动一个时钟。
其中的信号采用ACE最简单的处理方法，[把黑体字部分去除，你就会看到僵尸进程噢！：）]
#include "ace/OS_NS_unistd.h"
#include "ace/Log_Msg.h"
#include "ace/Process_Manager.h"
#include "ace/Signal.h"
pid_t RunThreeProgram(pid_t pid_cur);
/* 下面用来处理SIGCHLD信号
#if defined (ACE_HAS_SIG_C_FUNC)
extern "C" {
#endif
static void my_sighandler (int signo)
{
ACE_TRACE (ACE_TEXT ("::my_sighandler"));
if (signo == SIGCHLD)
ACE_DEBUG ((LM_DEBUG, ACE_TEXT ("Signal SIGCHLD\n")));
}
#if defined (ACE_HAS_SIG_C_FUNC)
}
#endif
int ACE_TMAIN (int argc, ACE_TCHAR *argv[])
{
ACE_OS::signal (SIGCHLD, (ACE_SignalHandler) my_sighandler);//指定SIGCHLD信号的处理函数
pid_t pids = ACE_INVALID_PID;
for(int i=0;i<30;i++)
{
pids = RunThreeProgram(pids);
ACE_DEBUG((LM_INFO,ACE_TEXT("Threads:[%d]\n"),pids));
ACE_OS::sleep(5);
}
if(getchar())
{
ACE_DEBUG((LM_INFO,ACE_TEXT("Over!\n));
}
return 0;
}
pid_t RunThreeProgram(pid_t pid_cur)
{
// Get the processwide process manager.
ACE_Process_Manager* pm = ACE_Process_Manager::instance ();
pm->terminate(pid_cur); //终止时会产生一个SIGCHLD信号
pm->wait(pidsss,0);
ACE_Process_Options options;
options.command_line (ACE_TEXT ("%s"), "/usr/bin/X11/xclock&");
// Spawn one child processes.
pid_t pids = pm->spawn(options);
return pids;
}
【附加】unix下标准C的信号捕获和id打印函数
void catch_signal(int signal_no)
{
switch(signal_no)
{
case SIGHUP:
printf("SIGHUP = %d\n",signal_no);
break;
case SIGINT:
printf("SIGINT = %d\n",signal_no);
exit(0);
break;
case SIGQUIT:
printf("SIGQUIT = %d\n",signal_no);
break;
case SIGILL:
printf("SIGILL = %d\n",signal_no);
break;
case SIGTRAP:
printf("SIGTRAP = %d\n",signal_no);
break;
case SIGABRT:
printf("SIGABRT = %d\n",signal_no);
break;
case SIGEMT:
printf("SIGEMT = %d\n",signal_no);
break;
case SIGFPE:
printf("SIGFPE = %d\n",signal_no);
break;
case SIGBUS:
printf("SIGBUS = %d\n",signal_no);
break;
case SIGSYS:
printf("SIGSYS = %d\n",signal_no);
break;
case SIGPIPE:
printf("SIGPIPE = %d\n",signal_no);
break;
case SIGSEGV:
printf("SIGSEGV = %d\n",signal_no);
exit(-1);
case SIGALRM:
printf("SIGALRM = %d\n",signal_no);
break;
case SIGTERM:
printf("SIGTERM = %d\n",signal_no);
break;
case SIGURG:
printf("SIGURG = %d\n",signal_no);
break;
case SIGTSTP:
printf("SIGTSTP = %d\n",signal_no);
break;
case SIGCONT:
printf("SIGCONT = %d\n",signal_no);
break;
case SIGCHLD:
printf("SIGCHLD = %d\n",signal_no);
break;
case SIGTTIN:
printf("SIGTTIN = %d\n",signal_no);
break;
case SIGTTOU:
printf("SIGTTOU = %d\n",signal_no);
break;
case SIGPOLL:
printf("SIGPOLL = %d\n",signal_no);
break;
case SIGXCPU:
printf("SIGXCPU = %d\n",signal_no);
break;
case SIGXFSZ:
printf("SIGXFSZ = %d\n",signal_no);
break;
case SIGVTALRM:
printf("SIGVTALRM = %d\n",signal_no);
break;
case SIGPROF:
printf("SIGPROF = %d\n",signal_no);
break;
case SIGWINCH:
printf("SIGWINCH = %d\n",signal_no);
break;
case SIGINFO:
printf("SIGINFO = %d\n",signal_no);
break;
}
return;
}
在main()中增加：
signal(SIGHUP,catch_signal);
signal(SIGINT,catch_signal);
signal(SIGQUIT,catch_signal);
signal(SIGILL,catch_signal);
signal(SIGTRAP,catch_signal);
signal(SIGABRT,catch_signal);
signal(SIGFPE,catch_signal);
signal(SIGSYS,catch_signal);
signal(SIGPIPE,catch_signal);
signal(SIGCHLD,catch_signal);
。。。。。。。。。。
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