src/docs/empty_loop.txt

   1 ### What it does
   2 Checks for empty `loop` expressions.
   3
   4 ### Why is this bad?
   5 These busy loops burn CPU cycles without doing
   6 anything. It is _almost always_ a better idea to `panic!` than to have
   7 a busy loop.
   8
   9 If panicking isn't possible, think of the environment and either:
  10   - block on something
  11   - sleep the thread for some microseconds
  12   - yield or pause the thread
  13
  14 For `std` targets, this can be done with
  15 [`std::thread::sleep`](https://doc.rust-lang.org/std/thread/fn.sleep.html)
  16 or [`std::thread::yield_now`](https://doc.rust-lang.org/std/thread/fn.yield_now.html).
  17
  18 For `no_std` targets, doing this is more complicated, especially because
  19 `#[panic_handler]`s can't panic. To stop/pause the thread, you will
  20 probably need to invoke some target-specific intrinsic. Examples include:
  21   - [`x86_64::instructions::hlt`](https://docs.rs/x86_64/0.12.2/x86_64/instructions/fn.hlt.html)
  22   - [`cortex_m::asm::wfi`](https://docs.rs/cortex-m/0.6.3/cortex_m/asm/fn.wfi.html)
  23
  24 ### Example
  25 ```
  26 loop {}
  27 ```