ZF-8176: $parent->isRunning() never updated after child proccess fork

Issue Type:
Bug
Created:
2009-10-29T09:47:43.000+0000
Last Updated:
2012-02-24T03:26:50.000+0000
Status:
Open
Fix version(s):
    Reporter:
    Victor Grachev (scriptbots)
    Assignee:
    Ben Scholzen (dasprid)
    Tags:
    • ZendX_Console_Process_Unix
    • zf-crteam-padraic
    • zf-crteam-priority
    Related issues:
    Attachments:

    Description

    This code I found in reference manual will never work, cose after fork child process will never change _isRunning variable in parent process and $process1->isRunning() will always return true even after child process stop running.

    ==================

    class MyProcess extends ZendX_Console_Process_Unix { protected function _run() { for ($i = 0; $i < 10; $i++) { // Doing something really important which can't wait: sleeping sleep(1); } } }

    // This part should last about 10 seconds, not 20. $process1 = new MyProcess(); $process1->start();

    $process2 = new MyProcess(); $process2->start();

    while ($process1->isRunning() && $process2->isRunning()) { sleep(1); }

    echo 'All processes completed';

    Comments

    Posted by Mark Nielsen (polothy) on 2009-11-18T13:18:20.000+0000

    I seem to be having the same problem, the processes run forever. I tried the ZendX_Console_Process_UnixTest::testParallel() code and it failed.

    Posted by Florian Hoenig (flo) on 2009-12-31T14:18:30.000+0000

    Same problem here!

    Posted by Florian Hoenig (flo) on 2010-01-04T14:26:43.000+0000

    This will fix the problem on OSX's WAITPID behavior (Linux not yet tested):

    public function isRunning() {
    $this->_isRunning = (0 == pcntl_waitpid($this->_pid, $status, WNOHANG)); return $this->_isRunning; }

    Posted by Sébastien Cramatte (scramatte) on 2010-01-06T02:13:10.000+0000

    The isRunning() fix seems to works under Linux too. I've tested under Debian Lenny.

    Posted by Florian Hoenig (flo) on 2010-01-07T13:27:04.000+0000

    Here is another fix.

    shmop_read returns a string and therefore it's ($okay === "0") instead of === 0.

    /**
 * Wait for IPC Semaphore
 * 
 * @return void
 */
private function _waitForIpcSemaphore()
{
    while (true) {
        $okay = shmop_read($this->_internalSemKey, 0, 1);
        if ($okay === "0") {
            break;
        }
        usleep(10);
    }
}

    Looks like the class is based on PHP_Fork from PEAR. Really needs some redesign.

    Posted by Ferenc Kovacs (tyrael) on 2010-03-29T05:45:58.000+0000

    I've had the the same problem, it seems that the isRunning is only good for checking, whether the process started or not. So I implemented an isFinished method with a getFinished and _setFinished. isFinished() returns whether or not the process is finished running, getFinished returns when was the _setFinished called, so it can be used for measuring the execution time.

    I'm gonna attach the patch.

    Tyrael

    Posted by Ferenc Kovacs (tyrael) on 2010-03-29T05:46:52.000+0000

    isFinished, getFinished, _setFinished

    Posted by Ferenc Kovacs (tyrael) on 2010-03-29T07:34:22.000+0000

    sorry, I missed something from the patch. I wanted to set the actual time in the _setFinished method, so the "true" should be "time()" there.

    Tyrael