Close non-stdio file handles when daemonizing #2314
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The test if env::var("SCCACHE_ERROR_LOG").is_ok() {
let f = create_error_log()?;
// Can't report failure here, we're already daemonized.
daemonize()?;
redirect_error_log(f)?;That code was opening a log file, daemonizing, then swapping stderr with it. We could pass the file descriptor of I'm updating the patch to make daemonize accept a log file as argument and do the file handle swap at that point, which also removes the need for the |
Otherwise, when the compiler wrapper spawns the sccache server, the server may end up with unintended file descriptors, which can lead to unexpected problems. This is particularly problematic if any of those file descriptors that accidentally end up in the server process is a pipe, as the pipe will only be closed when all the processes with that file descriptor close it or exit. This was causing sccache to hang ninja, as ninja uses the EOF of a pipe given to the subprocess to detect when that subprocess has exited: ninja-build/ninja#2444 (comment) This patch adds a dependency on the [close_fds](https://crates.io/crates/close_fds) crate, which automatically chooses an appropriate mechanism to close a range of file descriptors. On Linux 5.9+ that mechanism will be libc::close_range(). Fixes mozilla#2313
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Otherwise, when the compiler wrapper spawns the sccache server, the server may end up with unintended file descriptors, which can lead to unexpected problems.
This is particularly problematic if any of those file descriptors that accidentally end up in the server process is a pipe, as the pipe will only be closed when all the processes with that file descriptor close it or exit.
This was causing sccache to hang ninja, as ninja uses the EOF of a pipe given to the subprocess to detect when that subprocess has exited: ninja-build/ninja#2444 (comment)
This patch adds a dependency on the
close_fds crate, which automatically chooses an appropriate mechanism to close a range of file descriptors. On Linux 5.9+ that mechanism will be libc::close_range().
Fixes #2313