[sword-devel] thread-safety in libsword?

[Teus Benschop]

Hi,

The ticket about thread safety exactly describes the problems I am seeing :)

The code is this:

  sword::SWMgr manager (sword_logic_get_path ().c_str ());
  sword::SWModule *module = manager.getModule (module_name.c_str ());
  if (module) {
    string key = osis + " " + convert_to_string (chapter).c_str () + ":" +
convert_to_string (verse).c_str ();
    module->setKey (key.c_str ());
    rendering = module->renderText();
  }

Indeed, the crashes relate to "setKey" and "renderText", and not to "SWMgr".
But I am happy to surround the entire block with a mutex, and it's working
fine :)
Thank you for all your hard work!

Teus.

On Mon, 11 Jan 2016 at 17:33 Troy A. Griffitts <scribe at crosswire.org> wrote:

> Hi Teus,
>
> Yes, as Greg has pointed out, we've done our best to make it easy to
> perform multitheaded operations with the library by allowing you to
> instantiate a new SWMgr for each thread. We don't use threading libraries
> ourself inside the engine to lock critical sections but instead we tried to
> avoid critical sections within one instance of an SWMgr. We allocate a
> distinct instance of SWMgr per thread in many of our friends, e.g., one
> SWMgr for display and one for search so we can search in a separate thread.
>
> With a standard threading mechanism included in C++11 we might consider
> conditionally compiling in support to assure some iffy common sections of
> code are in fact safe. I am specifically thinking of junk buffers in SWBuf
> (but I think we cleaned those up) and also FileMgr, which handles closing
> and reopening file handles at the system level when resources are tight.
>
> On January 11, 2016 5:52:58 AM MST, Teus Benschop <teusjannette at gmail.com>
> wrote:
>
>> Hi,
>>
>> When accessing libsword simultaneously from multiple threads, it often
>> crashes. When surrounding the calls to the library with a mutex.lock and a
>> mutex.unlock at the end, there's no crashes when accessing it in the same
>> situation. I am seeing this on Linux and on the Mac. Should I do something
>> in the library, or make a special call, to make it thread-safe? Or is
>> surrounding the library calls with a mutex the recommended way to handle
>> this?
>>
>> Teus.
>>
>>
>> sword-devel mailing list: sword-devel at crosswire.org
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>>
> --
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