Expand documentation of process::exit and exec #38518
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| /// 1 | ||
| /// } | ||
| /// }); | ||
| /// } | ||
| /// ``` |
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What do you think about this as an example:
use std::io::{self, Write};
use std::process;
fn run_app() -> Result<(), ()> {
// Your application logic here
Ok(())
}
fn main() {
process::exit(match run_app() {
Ok(_) => 0,
Err(_) => 1,
});
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I personally prefer to not include an import for only one use of a function. I incorporated some of the other changes.
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Why are you printing the error if the error type is ()?
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I suppose I can see why, but it does seem unrelated to the point of this example. Not a big deal.
| @@ -67,10 +67,20 @@ pub trait CommandExt { | |||
| /// an error indicating why the exec (or another part of the setup of the | |||
| /// `Command`) failed. | |||
| /// | |||
| /// `exec` not returning has the same implications as calling | |||
| /// [`process::exit`] – no destructors on the current stack or any other | |||
| /// thread’s stack will be run. Therefore, it is recommended to only call | |||
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Would it be more accurate to replace "any other thread's" with "child thread's"?
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No. “Child thread” makes sense in relation to “main thread”, but you can call process::exit on any thread you want.
| /// `exec` at a point where it is fine to not run any destructors. Note, | ||
| /// that `execvp` syscall independently guarantees that all memory is freed | ||
| /// and all file descriptors with the `CLOEXEC` option (set by default on all | ||
| /// file descriptors opened by the standard library) are closed. |
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Is this platform specific behavior? I'm not familiar with how all the platforms handle execvp
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It is not. We always try our best to set CLOEXEC on all filedescriptors in the standard library and the behaviour of execvp wrt CLOEXEC fds is documented in posix: http://pubs.opengroup.org/onlinepubs/9699919799/functions/execvp.html
| /// [`process::exit`] – no destructors on the current stack or any other | ||
| /// thread’s stack will be run. Therefore, it is recommended to only call | ||
| /// `exec` at a point where it is fine to not run any destructors. Note, | ||
| /// that `execvp` syscall independently guarantees that all memory is freed |
| @@ -875,10 +875,23 @@ impl Child { | |||
| /// | |||
| /// # Examples | |||
| /// | |||
| /// Due to this function’s behaviour regarding destructors, a conventional way | |||
| /// to use the function is to extract the actual computation to another | |||
| /// function and compute exit code from its return value: | |||
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Ping? |
| @@ -875,10 +875,27 @@ impl Child { | |||
| /// | |||
| /// # Examples | |||
| /// | |||
| /// Due to this function’s behaviour regarding destructors, a conventional way | |||
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I think the documentation uses American English, so this should be "behavior"
alexcrichton
added
the
T-libs-api
Show a conventional way to use process::exit when destructors are considered important and also mention that the same caveats wrt destructors apply to exec as well.
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📌 Commit c2eab73 has been approved by |
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@bors rollup |
Expand documentation of process::exit and exec Show a conventional way to use process::exit when destructors are considered important and also mention that the same caveats wrt destructors apply to exec as well.
Expand documentation of process::exit and exec Show a conventional way to use process::exit when destructors are considered important and also mention that the same caveats wrt destructors apply to exec as well.
Show a conventional way to use process::exit when destructors are considered important and also
mention that the same caveats wrt destructors apply to exec as well.