c++ low-latency connectivity IV (nQuant) #2

This IV is heavy on low-level QQ in C/C++. Such obscure knowledge won’t help GTD and is not significant zbs. They may improve your design though.
Q3a: Memory alignment – what if on the stack I declare 2 char variables?
Q3b: what if I have 2 char fields in a struct?
Q3c: I have two 64-bit ints, one misaligned. When I use them what problems will I have? See https://lemire.me/blog/2012/05/31/data-alignment-for-speed-myth-or-reality/
Q1: If inside a member function I call “delete this”, what happens?
%%A: what if this “this” points to an object embedded as a field of an umbrella object? The deallocation would happen, but the destruction of the umbrella object may again deallocate it? This is confirmed in the FAQ (http://www.parashift.com/c++-faq-lite/delete-this.html)
%%A: how do we know the host obj is on heap, stack or global area
Q1b: To achieve heap-only, my class has private ctors and private op= and a static factory method. Will it work?
%%A: according to moreEffC++ P146, I would say yes, with certain caveats.
Q2: What’s reinterpret_cast vs dynamic_cast vs static_cast?
Q2b: What other casts are there?
Q: Placement new – can I use the regular “delete”?
%%A: probably no. Need to call the dtor manually? See P42 moreEffC++
Q: How does tcp handshake work? (I don’t know why this nlg is even relevant)
A: http://en.wikipedia.org/wiki/Transmission_Control_Protocol#Connection_establishment
Q: Some tcp parameter to speed it up?
A: larger TCP window size
Q: tcp client to specify a non-random port? See post on bind()
Q: If a c++ app runs fine in debug build (compiler optimizations removed), but crashes in release mode, what guesses/clues do you have?
%%A: conditional compilation, like in my c# project
%%A: the compiler optimization leads to unusual execution speed between 2 threads, and cooks up a rare corner case
%%A: I have seen assertions turned on in debug build (a debug STL can also be used), so we know one data file F1 is unusable, and another data file F2 is usable. In release build, someone else tries F1 and it crashes somewhere else.

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