Re: [Discuss-gnuradio] subprocess.Popen produces error in main()

[Eric Blossom]

On Thu, Nov 26, 2009 at 11:42:55AM +1100, Kyle Zhou wrote:
> Hi, I am trying to modify benchmark_rx.py such that it feeds to mplayer.
>
> I can successfully use gr.file_descriptor_sink and pipe the stdout of  
> python to stdin of mplayer.
>
> However, when I try to embed the pipe in python code by calling mplayer  
> programmably, it always produces errors.
> The code changes are:
>
> global n_rcvd, n_right, mplayer
> def main():
>    global n_rcvd, n_right, mplayer
>    n_rcvd = 0
>    n_right = 0
>    mplayer = subprocess.Popen(['mplayer','-'],stdin=subprocess.PIPE)
>      def rx_callback(ok, payload):
>        global n_rcvd, n_right, mplayer
>        ......
>        mplayer.stdin.write(payload[2:])
>
>
> Upon the line subprocess.Popen(...), it produces the following error:
>
>      3 [main] python 5020 C:\cygwin\bin\python.exe: *** fatal error -  
> unable to
> remap  
> C:\cygwin\lib\python2.5\site-packages\gnuradio\vocoder\_cvsd_vocoder.dll
> to same address as parent(0x1B260000) != 0x1B780000
>      5 [main] python 4344 fork: child 5020 - died waiting for dll  
> loading, errn
> o 11
> Traceback (most recent call last):
>  File "./benchmark_rx_mplayer.py", line 122, in <module>
>    main()
>  File "./benchmark_rx_mplayer.py", line 62, in main
>    mplayer =  
> subprocess.Popen(['mplayer','-'],stdin=subprocess.PIPE,stderr=ferr
> )
>  File "/usr/lib/python2.5/subprocess.py", line 594, in __init__
>    errread, errwrite)
>  File "/usr/lib/python2.5/subprocess.py", line 1011, in _execute_child
>    self.pid = os.fork()
> OSError: [Errno 11] Resource temporarily unavailable
>
>
> I don't think this code is related to vocoder in anyway. So the error  
> line 3 is really confusing.
> I guess there is some conflict when fork a process within main(). But how?
>
> Thanks
> Kyle

Kyle,

No clue.  Have you tried running this stuff on a native *nix box
instead of under cywin/windows?

Eric