Shared library : When are they loaded

https://stackoverflow.com/questions/29285546/when-do-so-files-get-loaded-linux

Threads

http://www.cs.iit.edu/~cs561/cs450/ChilkuriDineshThreads/dinesh%27s%20files/User%20and%20Kernel%20Level%20Threads.html

http://www.geeksforgeeks.org/multithreading-c-2/


Kernel level threads are 100 times slower than user level threads as kernel need to manage other processes as well & a thread is a overhead for the kernel. It makes things more complex for the kernel.

Important C++ concepts

-static member functions can directly be accessed. No need to create class object for accessing static variables.
-static classes do not exist.

-private constructors:
private  constructors exist, private destructors do not.
private constructors are used to create a singleton class.
http://www.yolinux.com/TUTORIALS/C++Singleton.html

protected constructors also exist. They are created so that only child class can call its constructor.





Virtual Destructors:
virtual destructors exist in C++. If we have a derived class object stored in base class pointer & if we delete that pointer, it will be undefined behaviour. So, we use virtual destructors for this purpose.
http://www.geeksforgeeks.org/virtual-destructor/

virtual constructors do not exist as there will be no point creating an object whose constructor is virtual. Creating an object is a compile time decision.
Except inline no other keyword is allowed with constructors.


Copy Constructor:
http://quiz.geeksforgeeks.org/copy-constructor-in-cpp/
http://www.geeksforgeeks.org/copy-constructor-vs-assignment-operator-in-c/

http://www.geeksforgeeks.org/can-virtual-functions-be-private-in-c/

Smart pointer impementation + explicit keyword + conversion constructor

http://www.geeksforgeeks.org/smart-pointers-cpp/
http://www.geeksforgeeks.org/g-fact-35/
http://www.geeksforgeeks.org/g-fact-93/

Exceptions Handling in C++

-If there is no catch statement for a try statement, then program ll not crash but will show abnormal behavior.

-try{
throw derived
}
catch(base){}
catch{derived}

The program will go in the base segment as it is written before derived statement.

-If you've one if/else block instead of one try/catch block, and if an exception throws in the try/catch block, then the if/else block is faster (if/else block: around 0.0012 milliseconds, try/catch block: around 0.6664 milliseconds). If no exception is thrown with a try/catch block, then a try/catch block is faster. But if you use 100 try/catch blocks in your program, and if one exception throws, then 100, if/else blocks, is faster.

static functions cannot be virtual

http://www.geeksforgeeks.org/g-fact-29/

Abstract class, sizeof class with virtual function

If we do not override the pure virtual function in derived class, then derived class also becomes abstract class.
http://www.geeksforgeeks.org/pure-virtual-functions-and-abstract-classes/

Sizeof class with virtual function maintins a virtual pointer which increases sizeof class by pointer size - 8 bytes.