fds: add make_fd_{,non}blocking implementations in Rust

fish-rust/src/fds.rs

@@ -3,10 +3,10 @@ use crate::ffi;
 use crate::wchar::{wstr, L};
 use crate::wutil::perror;
 use libc::EINTR;
-use libc::O_CLOEXEC;
+use libc::{fcntl, F_GETFL, F_SETFL, O_CLOEXEC, O_NONBLOCK};
 use nix::unistd;
 use std::ffi::CStr;
-use std::io::{Read, Write};
+use std::io::{self, Read, Write};
 use std::os::unix::io::{AsRawFd, FromRawFd, RawFd};
 
 pub const PIPE_ERROR: &wstr = L!("An error occurred while setting up pipe");
@@ -187,3 +187,29 @@ pub fn exec_close(fd: RawFd) {
         }
     }
 }
+
+/// Mark an fd as nonblocking
+pub fn make_fd_nonblocking(fd: RawFd) -> Result<(), io::Error> {
+    let flags = unsafe { fcntl(fd, F_GETFL, 0) };
+    let nonblocking = (flags & O_NONBLOCK) == O_NONBLOCK;
+    if !nonblocking {
+        match unsafe { fcntl(fd, F_SETFL, flags | O_NONBLOCK) } {
+            0 => return Ok(()),
+            _ => return Err(io::Error::last_os_error()),
+        };
+    }
+    Ok(())
+}
+
+/// Mark an fd as blocking
+pub fn make_fd_blocking(fd: RawFd) -> Result<(), io::Error> {
+    let flags = unsafe { fcntl(fd, F_GETFL, 0) };
+    let nonblocking = (flags & O_NONBLOCK) == O_NONBLOCK;
+    if nonblocking {
+        match unsafe { fcntl(fd, F_SETFL, flags & !O_NONBLOCK) } {
+            0 => return Ok(()),
+            _ => return Err(io::Error::last_os_error()),
+        };
+    }
+    Ok(())
+}

fish-rust/src/ffi.rs

@@ -55,7 +55,6 @@ include_cpp! {
 
     generate_pod!("wcharz_t")
     generate!("wcstring_list_ffi_t")
-    generate!("make_fd_nonblocking")
     generate!("wperror")
 
     generate_pod!("pipes_ffi_t")

fish-rust/src/io.rs

@@ -3,8 +3,9 @@ use crate::common::{str2wcstring, wcs2string, EMPTY_STRING};
 use crate::fd_monitor::{
     FdMonitor, FdMonitorItem, FdMonitorItemId, ItemWakeReason, NativeCallback,
 };
-use crate::fds::{make_autoclose_pipes, wopen_cloexec, AutoCloseFd, PIPE_ERROR};
-use crate::ffi;
+use crate::fds::{
+    make_autoclose_pipes, make_fd_nonblocking, wopen_cloexec, AutoCloseFd, PIPE_ERROR,
+};
 use crate::flog::{should_flog, FLOG, FLOGF};
 use crate::global_safety::RelaxedAtomicBool;
 use crate::job_group::JobGroup;
@@ -13,7 +14,7 @@ use crate::redirection::{RedirectionMode, RedirectionSpecList};
 use crate::signal::SigChecker;
 use crate::topic_monitor::topic_t;
 use crate::wchar::{wstr, WString, L};
-use crate::wutil::{perror, wdirname, wstat, wwrite_to_fd};
+use crate::wutil::{perror, perror_io, wdirname, wstat, wwrite_to_fd};
 use errno::Errno;
 use libc::{EAGAIN, EEXIST, EINTR, ENOENT, ENOTDIR, EPIPE, EWOULDBLOCK, O_EXCL, STDERR_FILENO};
 use std::cell::UnsafeCell;
@@ -343,10 +344,13 @@ impl IoBufferfill {
         // Our buffer will read from the read end of the pipe. This end must be non-blocking. This is
         // because our fillthread needs to poll to decide if it should shut down, and also accept input
         // from direct buffer transfers.
-        if ffi::make_fd_nonblocking(autocxx::c_int(pipes.read.fd())).0 != 0 {
-            FLOG!(warning, PIPE_ERROR);
-            perror("fcntl");
-            return None;
+        match make_fd_nonblocking(&pipes.read.fd()) {
+            Ok(_) => (),
+            Err(e) => {
+                FLOG!(warning, PIPE_ERROR);
+                perror_io("fcntl", &e);
+                return None;
+            }
         }
         // Our fillthread gets the read end of the pipe; out_pipe gets the write end.
         let mut buffer = Arc::new(RwLock::new(IoBuffer::new(buffer_limit)));

fish-rust/src/topic_monitor.rs

@@ -21,8 +21,7 @@ set. This is the real power of topics: you can wait for a sigchld signal OR a th
 */
 
 use crate::fd_readable_set::fd_readable_set_t;
-use crate::fds::{self, AutoClosePipes};
-use crate::ffi::{self as ffi, c_int};
+use crate::fds::{self, make_fd_nonblocking, AutoClosePipes};
 use crate::flog::{FloggableDebug, FLOG};
 use crate::wchar::WString;
 use crate::wutil::perror;
@@ -213,7 +212,7 @@ impl binary_semaphore_t {
             // receive SIGCHLD and so deadlock. So if tsan is enabled, we mark our fd as non-blocking
             // (so reads will never block) and use select() to poll it.
             if cfg!(feature = "FISH_TSAN_WORKAROUNDS") {
-                ffi::make_fd_nonblocking(c_int(pipes_.read.fd()));
+                let _ = make_fd_nonblocking(&pipes_.read.fd());
             }
         }
         binary_semaphore_t {