Fault injection

Inspired mainly by https://gitlab.com/Lipovsky/twist (mostly we rewrote it to achieve our goals), and also:

• https://github.com/ClickHouse/ClickHouse/blob/master/src/Common/ThreadFuzzer.h
• https://github.com/dvyukov/relacy
• https://github.com/apple/foundationdb/tree/main/flow
• papers about fault injection and model checking

Options

• YACLIB_FAULT=OFF:

  Just using for ::std primitives

• YACLIB_FAULT=THREAD:

  Thin wrappers for ::std primitives with fault injection calls (sleep_for, yield etc.) in some of the methods

  So it should be able to work in any environment, for example you cannot replace all primitives for yaclib_std::

• YACLIB_FAULT=FIBER:

  Single thread cooperative, deterministic execution, trying to be ::std compatible.

  Using fiber instead of std::thread and cooperative primitives for it with our own fiber scheduler.

• TODO(MBkkt) Write about runtime configuration options

Advantages

• You can just grep for header names <thread>, <atomic> etc. and replace them with<yaclib_std/thread>, <yaclib_std/atomic>. Similarly you can replace names from the standard library, e.g. std::thread, std::atomic etc. and replace them with YACLib equivalents yaclib_std::thread, yaclib_std::atomic, ....

  And everything will just work.

• FIBER backend adopted to easily run with any test framework, check our test main
• Trying to be fully C++17 ::std compatible, except std::future/etc, because we suggest YACLib as drop-in alternative