[lldb-dev] Process spawning and shutdown

[Zachary Turner]

Sure, but debugserver still has to launch processes locally w/r/t itself,
so this code would jsut be used there instead of in lldb.  Also, it's not
clear what the timeline is and waiting would jsut be lost time, so even if
some of what I do now has to be redone in the debugserver world, it's still
better than being blocked now and not being able to do anything :)

On Tue, Sep 16, 2014 at 1:12 PM, Todd Fiala <tfiala at google.com> wrote:

> > For now, the abstraction I'm creating deals only with local processes.
>
> For MacOSX, the local process uses debugserver for debugging (i.e. it is
> always remote w/r/t process startup --- lldb will launch and debugserver
> will attach).
>
> Linux is moving this way as well once we (1) get llgs passing the local
> test suite with llgs in place of ProcessLinux/ProcessMonitor, and (2) get
> llgs supporting the existing set of ProcessLinux/ProcessMonitor cpu
> architectures.  It will be on a PlatformLinux switch that defaults to
> current TOT behavior until then.  (See http://github.com/tfiala/lldb in
> the dev-llgs-local-launch branch for current state).
>
> Not sure that affects anything but wanted to be clear on it.
>
> On Tue, Sep 16, 2014 at 12:26 PM, Zachary Turner <zturner at google.com>
> wrote:
>
>> Yea, I saw that as well.  For now, the abstraction I'm creating deals
>> only with local processes.  However, it has an interface that would in
>> theory allow a RemoteProcess to derive from it, so that local and remote
>> processes could be managed transparently.
>>
>> On Tue, Sep 16, 2014 at 12:07 PM, Todd Fiala <tfiala at google.com> wrote:
>>
>>> Don't forget we also have launching via Platform classes, which can end
>>> up kicking off a gdb-remote request to a lldb-platform or gdb-remote stub
>>> (llgs/debugserver).
>>>
>>> Also, ProcessGDBRemote is capable of kicking those off if it's using
>>> gdb-remote locally.
>>>
>>> So, if nothing else, there's the concept of a "launch via another
>>> mechanism."
>>>
>>> On Tue, Sep 16, 2014 at 11:55 AM, Zachary Turner <zturner at google.com>
>>> wrote:
>>>
>>>> The last major piece of the Host layer I'd like to address is process
>>>> launching and cleanup.  From looking over the code it seems we have the
>>>> following different ways to launch a process:
>>>>
>>>> MacOSX:
>>>>     * Applescript
>>>>     * XPC
>>>>     * posix_spawn
>>>>
>>>> Other posix variants:
>>>>     * posix_spawn
>>>>
>>>> Windows:
>>>>     * Native windows launcher
>>>>
>>>>
>>>> Among these, there are a couple of different ways to reap processes on
>>>> exit and/or "join" on them.  These are:
>>>>
>>>> MacOSX:
>>>>     * Applescript    [ No process reaping or monitoring occurs. ]
>>>>     * XPC               [ Uses MacOSX-specific dispatch library for
>>>> monitoring ]
>>>>     * posix_spawn [ Uses MacOSX-specific dispatch library for
>>>> monitoring ]
>>>>
>>>> Other posix variants:
>>>>     * posix_spawn   [ Launches a background thread to monitor for
>>>> process exit, join on the thread to join on the process ]
>>>>
>>>> Windows:
>>>>     * Native windows launcher  [ WaitForSingleObject ]
>>>>
>>>> A few questions:
>>>>
>>>> 1) Is Join() on a process a useful operation that people would be
>>>> interested in seeing implemented for all platforms?
>>>>
>>>> 2) On Linux at least, if you don't waitpid() on a process you'll end up
>>>> with zombies.  It seems this is true on MacOSX as well, because I see
>>>> waitpid() in StartMonitoringChildProcess.  Is this not true for the
>>>> Applescript launcher?  Why doesn't the Applescript launching code path call
>>>> StartMonitoringChildProcess() anywhere?
>>>>
>>>> 3) Speaking of the Applescript launcher, what is it and what is it used
>>>> for?
>>>>
>>>>
>>>> I'll probably have more questions as I wrap my head around this a
>>>> little more.  Thanks
>>>>
>>>> _______________________________________________
>>>> lldb-dev mailing list
>>>> lldb-dev at cs.uiuc.edu
>>>> http://lists.cs.uiuc.edu/mailman/listinfo/lldb-dev
>>>>
>>>>
>>>
>>>
>>> --
>>> Todd Fiala | Software Engineer | tfiala at google.com | 650-943-3180
>>>
>>
>>
>
>
> --
> Todd Fiala | Software Engineer | tfiala at google.com | 650-943-3180
>
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