From 70a6e6a9107166e6aead671ce1825f1f533d5faf Mon Sep 17 00:00:00 2001
From: Ben Noordhuis <info@bnoordhuis.nl>
Date: Thu, 21 Nov 2024 06:55:53 +0100
Subject: [PATCH] Use closefrom() to close open file descriptors

Replace the naive close() loop in js_os_exec with closefrom().

On my system RLIMIT_NOFILE is set to 1 million and the delay from the
loop gets noticeable when I spawn many processes.

Fixes: https://github.com/quickjs-ng/quickjs/issues/711
---
 quickjs-libc.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/quickjs-libc.c b/quickjs-libc.c
index 55a0eda6..11bf0ea3 100644
--- a/quickjs-libc.c
+++ b/quickjs-libc.c
@@ -3123,8 +3123,6 @@ static JSValue js_os_exec(JSContext *ctx, JSValue this_val,
     }
     if (pid == 0) {
         /* child */
-        int fd_max = sysconf(_SC_OPEN_MAX);
-
         /* remap the stdin/stdout/stderr handles if necessary */
         for(i = 0; i < 3; i++) {
             if (std_fds[i] != i) {
@@ -3132,9 +3130,13 @@ static JSValue js_os_exec(JSContext *ctx, JSValue this_val,
                     _exit(127);
             }
         }
-
+#if defined(__APPLE__)
+        int fd_max = sysconf(_SC_OPEN_MAX);
         for(i = 3; i < fd_max; i++)
             close(i);
+#else
+        closefrom(3);
+#endif
         if (cwd) {
             if (chdir(cwd) < 0)
                 _exit(127);