No no, It's perfectly fine, it was my fault. What I haven't realized is 
that if I start the server async then my script will finish immediately, 
which also terminated the server. It was my responsibility to keep the 
whole app alive now. 

It works like a charm! 


sâmbătă, 23 ianuarie 2016, 00:06:13 UTC+1, Stefan Karpinski a scris:
>
> The shell works with processes, Julia has tasks where are not the same 
> thing...
>
> On Fri, Jan 22, 2016 at 5:49 PM, Adrian Salceanu <[email protected] 
> <javascript:>> wrote:
>
>> The problem seems to that HttpServer can not run @async - it exits 
>> immediately. 
>>
>> ===
>>
>> using HttpServer
>>
>> http = HttpHandler() do req::Request, res::Response
>>     Response( ismatch(r"^/hello/", req.resource) ? exit(2) : 404 )
>> end
>>
>> server = Server( http )
>> run( server, 8001 )  # <--- this works but blocks
>> @async run( server, 8001 ) # <--- this exits immediately
>>
>> ===
>>
>> It's not necessarily a problem that HttpServer blocks. But what drives me 
>> nuts is: if I run 
>> $ julia app.jl & 
>> in the shell, it works perfectly. The process is placed in the 
>> background, the server happily listens to the assigned port, etc. 
>>
>> Why can't I run the same command from within another julia process and 
>> get the same effect? 
>>
>>
>> vineri, 22 ianuarie 2016, 22:40:56 UTC+1, Stefan Karpinski a scris:
>>>
>>> @spawn runs a command on a (random) worker process. If you want to do 
>>> "background" work in the current process, you can use @async:
>>>
>>> julia> t = @async (sleep(5); rand())
>>> Task (runnable) @0x0000000112d746a0
>>>
>>> julia> wait(t)
>>> 0.14543742643271207
>>>
>>>
>>> On Fri, Jan 22, 2016 at 4:33 PM, Adrian Salceanu <[email protected]> 
>>> wrote:
>>>
>>>> Oh! The ruby analogy made me think about actually spawning the detached 
>>>> command! Which produced the desired effect! 
>>>>
>>>> julia> @spawn run(detach(`ping www.google.com`))
>>>>
>>>>
>>>>
>>>> vineri, 22 ianuarie 2016, 22:29:27 UTC+1, Adrian Salceanu a scris:
>>>>>
>>>>> I guess what I'm looking for is the equivalent of Ruby's Process#spawn
>>>>>
>>>>> In REPL: 
>>>>>
>>>>> >> pid = Process.spawn("ping www.google.com", :out => '/dev/null')
>>>>> 83210
>>>>> >>                         <-- the process is running in the 
>>>>> background and control has been returned to the REPL
>>>>>
>>>>>
>>>>> vineri, 22 ianuarie 2016, 22:06:01 UTC+1, Adrian Salceanu a scris:
>>>>>>
>>>>>> Hi, 
>>>>>>
>>>>>> I'm hammering at a web app and I'm trying to setup functionality to 
>>>>>> monitor the file system for changes and restart/reload the server 
>>>>>> automatically so the changes are picked up (I'm using Mux which uses 
>>>>>> HttpServer). 
>>>>>>
>>>>>> The approach I have in mind is: 
>>>>>>
>>>>>> 1. have a startup script which is run from the command line, 
>>>>>> something like: 
>>>>>> $ julia -L startup.jl
>>>>>>
>>>>>> 2. the startup script launches the web app, which starts the web 
>>>>>> server. My intention was to run 
>>>>>> $ julia -L app.jl 
>>>>>> as a command inside startup.jl, detached, and have the startup.jl 
>>>>>> script get back control, with app.jl running detached in the background. 
>>>>>>
>>>>>> 3. once startup.jl gets back control, it begins monitoring the file 
>>>>>> system and when changes are detected, kills the app and relaunches it. 
>>>>>>
>>>>>> That was the theory. Now, I might be missing something but I can't 
>>>>>> find a way to detach the command I'm running and get control back to the 
>>>>>> startup script. And I tried a lot of things! 
>>>>>>
>>>>>> ===
>>>>>>
>>>>>> I'm providing simpler example using "ping", which also run 
>>>>>> indefinitely, similar to the web server. 
>>>>>>
>>>>>> julia> run(detach(`ping "www.google.com"`)) # the command is 
>>>>>> detached and continues to run after the julia REPL is closed, but at 
>>>>>> this 
>>>>>> point the REPL does not get control, there's no cursor available in the 
>>>>>> REPL
>>>>>> PING www.google.com (173.194.45.82): 56 data bytes
>>>>>> 64 bytes from 173.194.45.82: icmp_seq=0 ttl=54 time=30.138 ms
>>>>>> 64 bytes from 173.194.45.82: icmp_seq=1 ttl=54 time=30.417 ms
>>>>>> ... more output ...
>>>>>> 64 bytes from 173.194.45.82: icmp_seq=7 ttl=54 time=30.486 ms
>>>>>> 64 bytes from 173.194.45.82: icmp_seq=8 ttl=54 time=30.173 ms
>>>>>> ^CERROR: InterruptException:                                         
>>>>>>                         <---- here I press Ctrl+C and only now the REPL 
>>>>>> gets back the cursor, with the command still running in the background
>>>>>>
>>>>>> ===
>>>>>>
>>>>>> Also, related to this, passing "&" into the command to detach does 
>>>>>> not work as expected, the "&" is interpreted as argument of the command. 
>>>>>> Not sure if this would help anyway to return control to the startup.jl 
>>>>>> script? 
>>>>>>
>>>>>> julia> run(detach(`ping "www.google.com" &`));
>>>>>> usage: ping [-AaDdfnoQqRrv] [-b boundif] [-c count] [-G sweepmaxsize]
>>>>>>             [-g sweepminsize] [-h sweepincrsize] [-i wait] [−k 
>>>>>> trafficclass]
>>>>>>             [-l preload] [-M mask | time] [-m ttl] [-p pattern]
>>>>>>             [-S src_addr] [-s packetsize] [-t timeout][-W waittime] 
>>>>>> [-z tos]
>>>>>>             host
>>>>>>        ping [-AaDdfLnoQqRrv] [-b boundif] [-c count] [-I iface] [-i 
>>>>>> wait]
>>>>>>             [−k trafficclass] [-l preload] [-M mask | time] [-m ttl] 
>>>>>> [-p pattern] [-S src_addr]
>>>>>>             [-s packetsize] [-T ttl] [-t timeout] [-W waittime]
>>>>>>             [-z tos] mcast-group
>>>>>> ERROR: failed process: Process(`ping www.google.com &`, 
>>>>>> ProcessExited(64)) [64]
>>>>>>  in run at /usr/local/Cellar/julia/0.4.2/lib/julia/sys.dylib
>>>>>>
>>>>>> ===
>>>>>>
>>>>>> Thanks
>>>>>>
>>>>>
>>>
>

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