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  • Jonathan Wilkes's avatar
    get the "-unique" flag and [pd~] object working in Purr Data · a147dfbb
    Jonathan Wilkes authored
    This patch makes it possible to have multiple running instances of Purr Data,
    and to leverage that interface from Pd-l2ork to get [pd~] working on all
    platforms
    
    Some difficulties required revisions to [pd~] in Pd Vanilla's code
    * use quoted path args for Windows when starting the [pd~] subprocess
    * replace sys_havegui() from Pd Vanilla's recent "threadening" with sys_nogui
    
    The "-unique" flag requires the OSX app bundle to be able to start by calling
    the binary in Pd-l2ork.app/Contents/Resources/app.nw/bin/pd-l2ork. This should
    also make it possible to run Purr Data on OSX both by using an app bundle
    (where the GUI starts the Pd process) and by installing and running from the
    command line (where the Pd process starts the GUI)
    
    The "--user-data-dir" flag sets the directory for various nw.js state used
    by a running instance. To prevent races nw.js requires that each running
    instance have its own directory that is not shared with any other instances.
    
    Setting the value for this flag has two important potential side-effects:
    
    1. If you have a running instance and try to start an additional instance
       that has the same data directory, nw.js will just send an "open" event
       the first running instance and exit the 2nd instance gracefully. This is
       the default nw.js behavior and the default Pd-l2ork behavior as well.
    2. If you have a running instance and try to start an additional instance
       with a different data directory than the first, you'll get a fully
       functional 2nd instance of nw.js running. This is the behavior we desire
       when the user runs pd-l2ork with the "-unique" flag.
    
    In each case we set the data dir explicitly in order to get consistent
    positional command line arguments in the GUI.
    
    In normal mode Purr Data will use the default data dir as specified in the
    nw.js docs for the particular platorm. Since the same default dir is used
    each time Purr Data is run, there will be only one data dir that gets created.
    
    When run with the "-unique" flag, Purr Data will append "-$portno" to the
    default data directory, where $portno is the port Pd chose to communicate
    with the GUI. That ensures that each separate instance of Purr Data can
    get a unique data dir.
    
    A side effect is that users may end up generating multiple data dirs that
    don't get deleted on exit. But Pd starts searching for available ports in the
    same range each time, and unless the user tries to run hundreds of instances
    at once this directory spam shouldn't be too big of a problem.
    a147dfbb