Sign Up to our social questions and Answers Engine to ask questions, answer people’s questions, and connect with other people.
Login to our social questions & Answers Engine to ask questions answer people’s questions & connect with other people.
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Please briefly explain why you feel this question should be reported.
Please briefly explain why you feel this answer should be reported.
Please briefly explain why you feel this user should be reported.
In *nix .so libraries, is there an entry point that’s invoked by the system when the library is loaded and unloaded?
On a more practical note: if the .so was written in C++ and it contains global objects with constructors and destructors, and it’s loaded from a language that has no notion of construction/destruction, are the global objects properly constructed/destructed?
No, there is no equivalent to DllMain.
For JNI libraries, e.g. on Android, there may be a special entry JNI_OnLoad which is intended to fill JNI function table.
GCC defines special attribute constructor to allow some code to run on shared library load.
C++ guarantees that the constructors for global and static objects will be performed, no matter if the code that loaded the .so was aware of these classes, or had notion of construction.
Same holds for destructors, but there may be unhappy circumstances when at least some destructors have no chance to run – e.g. when there is a sigfault and exceptions are disabled.