Question

如果我的应用程序崩溃，我没有机会终止它产生的NSTasks，所以他们留下来吃掉资源。

有没有办法启动任务，以便在您的应用终止时终止（即使崩溃）？

Answer 1

我认为您需要手动处理应用程序崩溃，并以不同的方式终止生成的进程。例如，您可以检查以下文章http://cocoawithlove.com/2010/05/handling-unhandled-exceptions-and.html和异常/信号处理程序，当应用程序崩溃时使用kill（pid，SIGKILL）向您的子进程发送终止信号，但为此您还需要保留子进程的pid进程（NSTask - （int）processIdentifier）从异常/信号处理程序获取它。

Answer 2

我实际上是wrote a program / script / whatever that does just this ...这是作为它的基础的shell脚本......项目实际上在X代码中将它作为单个文件可执行文件实现..奇怪的是，苹果使得它如此不稳定，IMO。

#!/bin/bash
echo "arg1 is the SubProcess: $1, arg2 is sleepytime: $2, and arg3 is ParentPID, aka $$: $3"
CHILD=$1 && SLEEPYTIME=$2 || SLEEPYTIME=10; PARENTPID=$3 || PARENTPID=$$

GoSubProcess () {                      # define functions, start script at very end.
 $1 arguments &                         # "&" puts SubP in background subshell
 CHILDPID=$!                            # what all the fuss is about.
 if kill -0 $CHILDPID; then             # rock the cradle to make sure it aint dead
     echo "Child is alive at $!"        # glory be to god
 else echo "couldnt start child.  dying."; exit 2; fi
 babyRISEfromtheGRAVE # keep an eye on child process
}
babyRISEfromtheGRAVE () {
echo "PARENT is $PARENTPID";            # remember where you came from, like j.lo
while kill -0 $PARENTPID; do            # is that fount of life, nstask parent alive?
    echo "Parent is alive, $PARENTPID is it's PID"
    sleep $SLEEPTIME                    # you lazy boozehound
    if kill -0 $CHILDPID; then      # check on baby.
        echo "Child is $CHILDPID and is alive."
        sleep $SLEEPTIME                # naptime!
    else echo "Baby, pid $CHILDPID died!  Respawn!"
        GoSubProcess; fi                # restart daemon if it dies
done                                    # if this while loop ends, the parent PID crashed.
logger "My Parent Process, aka $PARENTPID died!"
logger "I'm killing my baby, $CHILDPID, and myself."
kill -9 $CHILDPID; exit 1               # process table cleaned.  nothing is left.  all three tasks are dead.  long live nstask.
}
GoSubProcess                # this is where we start the script.
exit 0                      # this is where we never get to

Answer 3

我过去所做的是在父进程中创建一个管道，并将该管道的写入端传递给子进程。父节点从不关闭读取结束，并且子节点监视写入结束。如果写入结束，则表示父项已退出。您还需要将管道的父管道末端标记为在exec上关闭。

Answer 4

您可以定期检查您的任务，看看他们的父进程是否仍然存在。

即使应用程序崩溃，也要终止NSTask

4 个答案: