From a52c79e859142c1cd5c0c5bdb73f16b754e1b98f Mon Sep 17 00:00:00 2001 From: Rain Date: Thu, 22 Sep 2022 22:48:14 -0700 Subject: Change process spawning to inherit the parent's signal mask by default Previously, the signal mask is always reset when a child process is started. This breaks tools like `nohup` which expect `SIGHUP` to be blocked. With this change, the default behavior changes to inherit the signal mask. This also changes the signal disposition for `SIGPIPE` to only be changed if the `#[unix_sigpipe]` attribute isn't set. --- src/doc/unstable-book/src/language-features/unix-sigpipe.md | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'src/doc') diff --git a/src/doc/unstable-book/src/language-features/unix-sigpipe.md b/src/doc/unstable-book/src/language-features/unix-sigpipe.md index aa39b6eb288..7ed6a7de895 100644 --- a/src/doc/unstable-book/src/language-features/unix-sigpipe.md +++ b/src/doc/unstable-book/src/language-features/unix-sigpipe.md @@ -36,7 +36,7 @@ hello world Set the `SIGPIPE` handler to `SIG_IGN` before invoking `fn main()`. This will result in `ErrorKind::BrokenPipe` errors if you program tries to write to a closed pipe. This is normally what you want if you for example write socket servers, socket clients, or pipe peers. -This is what libstd has done by default since 2014. Omitting `#[unix_sigpipe = "..."]` is the same as having `#[unix_sigpipe = "sig_ign"]`. +This is what libstd has done by default since 2014. (However, see the note on child processes below.) ### Example @@ -52,3 +52,11 @@ hello world thread 'main' panicked at 'failed printing to stdout: Broken pipe (os error 32)', library/std/src/io/stdio.rs:1016:9 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace ``` + +### Note on child processes + +When spawning child processes, the legacy Rust behavior if `#[unix_sigpipe]` is not specified is to +reset `SIGPIPE` to `SIG_DFL`. + +If `#[unix_sigpipe = "..."]` is specified, no matter what its value is, the signal disposition of +`SIGPIPE` is no longer reset. This means that the child inherits the parent's `SIGPIPE` behavior. -- cgit 1.4.1-3-g733a5