pcntl_wait函數掛起父類進程失敗

sum =2 時為什麼不會掛起父進程呢

$sum = 0;

    while(true){        $sum++;        $pid= pcntl_fork();        switch($pid){            case "-1":                echo"couldn't fork";                break;            case "0":{                var_dump(getmypid());                var_dump(pcntl_wifexited($status), pcntl_wifstopped($status), pcntl_wifsignaled($status), pcntl_wexitstatus($status), pcntl_wtermsig($status));                echo 'ppppppppp';

                exit(0);            }            default: {                if($sum == 2){                   // $subPid = pcntl_waitpid(-1, $status, SI_ASYNCIO);                   $subPid = pcntl_wait($status);                    echo '掛起'."\n";                }                var_dump('主'.getmypid());                var_dump($subPid);                echo "I'm child" . getmypid() . "\n";                echo 'ccp';                //就會執行子進程                sleep(30);                echo "\n\n\n";            }              //  exit(0);        }        var_dump(getmypid());        echo 'iiiiiii';        if($sum == 2)        break;    }            這個是答案                     string(8) "主26003"

NULL
I'm child26003
ccpint(26004)
bool(true)
bool(false)
bool(false)
int(0)
int(0)
ppppppppp

int(26003)
iiiiiii掛起
string(8) "主26003"
int(26004)
I'm child26003
ccpint(26005)
bool(true)
bool(false)
bool(false)
int(0)
int(0)
ppppppppp

int(26003)
iiiiiii

回複內容：

sum =2 時為什麼不會掛起父進程呢

$sum = 0;

    while(true){        $sum++;        $pid= pcntl_fork();        switch($pid){            case "-1":                echo"couldn't fork";                break;            case "0":{                var_dump(getmypid());                var_dump(pcntl_wifexited($status), pcntl_wifstopped($status), pcntl_wifsignaled($status), pcntl_wexitstatus($status), pcntl_wtermsig($status));                echo 'ppppppppp';

                exit(0);            }            default: {                if($sum == 2){                   // $subPid = pcntl_waitpid(-1, $status, SI_ASYNCIO);                   $subPid = pcntl_wait($status);                    echo '掛起'."\n";                }                var_dump('主'.getmypid());                var_dump($subPid);                echo "I'm child" . getmypid() . "\n";                echo 'ccp';                //就會執行子進程                sleep(30);                echo "\n\n\n";            }              //  exit(0);        }        var_dump(getmypid());        echo 'iiiiiii';        if($sum == 2)        break;    }            這個是答案                     string(8) "主26003"

NULL
I'm child26003
ccpint(26004)
bool(true)
bool(false)
bool(false)
int(0)
int(0)
ppppppppp

int(26003)
iiiiiii掛起
string(8) "主26003"
int(26004)
I'm child26003
ccpint(26005)
bool(true)
bool(false)
bool(false)
int(0)
int(0)
ppppppppp

int(26003)
iiiiiii

