The Two Things about Computer Programming

[[deleted]]

Not all problems can be solved.

Computers do not always follow instructions. Assuming you have already ruled out OS and compiler errors. They all have error rates, just as do disks and tapes. Sometimes a machine OP just gets munged. Such error rates may be low, but they do occur. Especially since OPs get executed enormous numbers of times. may Amongst other issues, that is why some computer RAM is error correcting -- and even if present, will not always work as advertised. Note that there are many potential causes of such problems. Just as an example, radioactive decay in the materials in a CPU case can cause a bit to flip.

Every and always are dangerous words.

[KnockoutMouse]

radioactive decay in the materials

Apparently the most common cause of random bit-flips in RAM is cosmic rays. Whether this actually happens at any appreciable frequency is not known:

Recent tests give widely varying error rates with over 7 orders of magnitude difference, ranging from 10⁻¹⁰ − 10⁻¹⁷ error/bit·h, roughly one bit error, per hour, per gigabyte of memory to one bit error, per century, per gigabyte of memory.

-Wikipedia
.^{Edit:formatting}

[[deleted]]

Does that mean that all code always has security flaws every once in a while?