On 01/07/15 10:06, Dan Olson wrote:
The private APIs being called by osx_tls.c like
dyld_enumerate_tlv_storage() are overriden for iOS by using [1]. I can
change all dyld prefixes in theadLocalVariable.c to something else and
remove all code not needed.
Right, I forgot that you have implemented those functions yourself. But
removing the "dyld" prefix might be a good idea.
That would leave a call to private API
dyld_register_image_state_change_handler() in threadLocalVariables.c,
but it looks to me like it could be rewritten to use
_dyld_register_func_for_add_image(). Tried it and seems to work.
_dyld_register_func_for_add_image won't work for dynamic libraries.
There's no API to unregister the callback. So, if
_dyld_register_func_for_add_image is called from a dynamic library then
the library is unloaded. The next call to any of the "dl" functions,
i.e. "dlopen" will crash.
dyld_register_image_state_change_handler works because it pins the
dynamic library, if I recall correctly. It won't unload it.
_dyld_register_func_for_add_image is already used by druntime, perhaps
it doesn't matter. I think bitwise is working on adding support for
dynamic libraries on OS X. On Linux the compiler is generating a
function that behave as the C function with the attribute
__attribute__((constructor)). Perhaps that can be used.
Otherwise perhaps look at the implementation of
dyld_register_image_state_change_handler and see if you can manually pin
the dynamic library.
--
/Jacob Carlborg
