Re: How to disable RTLD_NOW for Python 2.7.x dlopen() in Mac OS X Mavericks?
On Thursday, November 14, 2013 11:44:44 AM UTC+8, Ned Deily wrote: I'm not very familiar with ctypes internals but it looks like sys.setdlopenflags is not intended to have an influence on ctypes; rather, it conditions the Python interpreter's use of dlopen to load shared Python modules. For ctypes itself, it looks like it unconditionally sets RTLD_NOW when calling dlopen and probably with good reason: http://hg.python.org/cpython/file/2.7/Modules/_ctypes/callproc.c#l1432 Ah, thanks for the link. I couldn't figure out where the RTLD_NOW flag was set. Sorry, I don't have a suggestion for you, assuming you want to just try to ignore the error, other than perhaps running an older version of OS X in a VM on 10.8. That's not an option for me unfortunately. Guess I'll have to look into other alternatives to solve the missing symbol problem. T. C. -- https://mail.python.org/mailman/listinfo/python-list
How to disable RTLD_NOW for Python 2.7.x dlopen() in Mac OS X Mavericks?
Hi, I've tried searching for topics related to dlopen() of dynamic libraries in the list but there's nothing relevant or recent. I'm facing a problem with a 3rd party C/C++ Framework (dynamic library) on Mac OS X which I'm trying to import into Python using ctypes. Unfortunately OS X has deprecated a function which is called from the Framework and is no longer available as of 10.8+ (Mtn. Lion, now updated to Mavericks). In addition, there is no recent version of the 3rd party framework available and it does not look like it's actively updated. (The 3rd party framework in question is the Fantom framework/driver for the LEGO Mindstorms NXT/EV3). Existing tools using the 3rd party framework runs ok, but attempting to access it using ctypes fails with a Symbol not Found error when Python 2.7.x attempts to dlopen() the library. I suspect it is due to the setting of RTLD_NOW when opening the framework. I'd like to try to specify RTLD_LAZY instead. Unfortunately sys.setdlopenflags(0) does not appear to do anything. RTLD_NOW is still set, which I presume overrides RTLD_LAZY if both flags were set. I've tried this with both the Apple supplied python and the version from MacPorts. Enclosed is a snippet of the code and the Traceback. Is there a way to force RTLD_NOW off? [code] # Load library. #dll = ctypes.cdll.LoadLibrary(libpath) RTLD_LAZY = 1 sys.setdlopenflags(0) print dlopen() flags = %d % sys.getdlopenflags() dll = ctypes.CDLL(libpath, RTLD_LAZY) [/code] [traceback] $ arch -i386 python --version Python 2.7.5 $ arch -i386 python pyfantom.py Running on Darwin Platform (Rel. 13.0.0) Bluetooth Stack not supported (Rel = 12.0.0) Found Fantom Library ( /Library/Frameworks/fantom.framework/fantom ) dlopen() flags = 0 Traceback (most recent call last): File pyfantom.py, line 83, in module dll = ctypes.CDLL(libpath, RTLD_LAZY) File /opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/ctypes/__init__.py, line 365, in __init__ self._handle = _dlopen(self._name, mode) OSError: dlopen(/Library/Frameworks/fantom.framework/fantom, 3): Symbol not found: _IOBluetoothSDPServiceRecordGetRFCOMMChannelID Referenced from: /Library/Frameworks/fantom.framework/fantom Expected in: /System/Library/Frameworks/IOBluetooth.framework/Versions/A/IOBluetooth [/traceback] -- https://mail.python.org/mailman/listinfo/python-list
Re: How to disable RTLD_NOW for Python 2.7.x dlopen() in Mac OS X Mavericks?
In article c9bc3283-e895-4d9f-a749-fc35497a8...@googlegroups.com, tcwa...@gmail.com wrote: I'm facing a problem with a 3rd party C/C++ Framework (dynamic library) on Mac OS X which I'm trying to import into Python using ctypes. Unfortunately OS X has deprecated a function which is called from the Framework and is no longer available as of 10.8+ (Mtn. Lion, now updated to Mavericks). In addition, there is no recent version of the 3rd party framework available and it does not look like it's actively updated. (The 3rd party framework in question is the Fantom framework/driver for the LEGO Mindstorms NXT/EV3). Existing tools using the 3rd party framework runs ok, but attempting to access it using ctypes fails with a Symbol not Found error when Python 2.7.x attempts to dlopen() the library. I suspect it is due to the setting of RTLD_NOW when opening the framework. I'd like to try to specify RTLD_LAZY instead. Unfortunately sys.setdlopenflags(0) does not appear to do anything. RTLD_NOW is still set, which I presume overrides RTLD_LAZY if both flags were set. I've tried this with both the Apple supplied python and the version from MacPorts. Enclosed is a snippet of the code and the Traceback. Is there a way to force RTLD_NOW off? I'm not very familiar with ctypes internals but it looks like sys.setdlopenflags is not intended to have an influence on ctypes; rather, it conditions the Python interpreter's use of dlopen to load shared Python modules. For ctypes itself, it looks like it unconditionally sets RTLD_NOW when calling dlopen and probably with good reason: http://hg.python.org/cpython/file/2.7/Modules/_ctypes/callproc.c#l1432 Sorry, I don't have a suggestion for you, assuming you want to just try to ignore the error, other than perhaps running an older version of OS X in a VM on 10.8. -- Ned Deily, n...@acm.org -- https://mail.python.org/mailman/listinfo/python-list
