Demo: The Same Address, Twice

Two copies of one program, each printing the address of a global and the value it stored there.

Run

Two terminals, one copy in each:

make
./same_address

Leave both waiting and compare.

Ask

• &value is 0x404040 in both. The values differ. Where are the two bytes?
• Press Enter in one copy. Did the other copy's write reach it?
• main() is at the same address too. Is that one copy of the code, or two?
• The local variable's address differs between the two runs. What moved it?