Waiting for a Spawn'ed process

[Ali Çehreli]

On 03/28/2014 10:19 AM, Sharad Gupta wrote:
> On Friday, 28 March 2014 at 16:37:00 UTC, Vladimir Panteleev wrote:
>> On Friday, 28 March 2014 at 15:52:17 UTC, Sharad Gupta wrote:
>>> I am trying to make a Utility which spwans=>pipeShell off multiple
>>> processes on user choice.
>>>
>>> On of the issues is that some process need to wait for other
>>> processes to finish. Now I could implement it using messages but that
>>> doesn't seem very nice solution. I could also wait for the pipeShell
>>> pid but was wondering what is the standard or recommended way to wait
>>> on a spawned process?
>>
>> Calling wait on the Pid object returned by std.process functions is
>> the standard way to wait for a process to finish in D.
>
> But I don't have a Pid object but instead have Tid object from the spawn
> function in std.concurrency lib.

If you start the worker with spawnLinked then you will receive a 
LinkTerminated message.

import std.stdio;
import std.concurrency;
import core.thread;

void main()
{
     auto worker = spawnLinked(&workerFunc);

     // Wait for worker to terminate
     bool terminated = false;
     while (!terminated) {
         writeln("Waiting for the worker to terminate...");

         terminated = receiveTimeout(1.seconds,
             (LinkTerminated e) {
                 if (e.tid == worker) {
                     writefln("Terminated");
                 }
             }
         );
     }
}

void workerFunc()
{
     Thread.sleep(3.seconds);
}

Ali