DoneJS/quickjs-done-nextgen
1
0
Fork 0
mirror of https://github.com/DoneJS-Runtime/quickjs-done-nextgen.git synced 2025-01-09 17:43:15 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

Use closefrom() to close open file descriptors (#712)

Browse source 
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.

Use dlsym() to look up closefrom() because it's not available everywhere
(looking at you, musl.)

Fixes: https://github.com/quickjs-ng/quickjs/issues/711
This commit is contained in:
Ben Noordhuis 2024-11-21 20:43:18 +01:00 committed by GitHub
parent 010777f259
commit 81e50f3cae
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
1 changed files with 21 additions and 4 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

25
quickjs-libc.c
View file

@ -2997,6 +2997,15 @@ static int my_execvpe(const char *filename, char **argv, char **envp)
return -1;
}
static js_once_t js_os_exec_once = JS_ONCE_INIT;
static void (*js_os_exec_closefrom)(int);
static void js_os_exec_once_init(void)
{
js_os_exec_closefrom = dlsym(RTLD_DEFAULT, "closefrom");
}
/* exec(args[, options]) -> exitcode */
static JSValue js_os_exec(JSContext *ctx, JSValue this_val,
int argc, JSValue *argv)
@ -3116,6 +3125,10 @@ static JSValue js_os_exec(JSContext *ctx, JSValue this_val,
}
}
// should happen pre-fork because it calls dlsym()
// and that's not an async-signal-safe function
js_once(&js_os_exec_once, js_os_exec_once_init);
pid = fork();
if (pid < 0) {
JS_ThrowTypeError(ctx, "fork error");
@ -3123,8 +3136,6 @@ 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) {
@ -3133,8 +3144,14 @@ static JSValue js_os_exec(JSContext *ctx, JSValue this_val,
}
}
for(i = 3; i < fd_max; i++)
close(i);
if (js_os_exec_closefrom) {
js_os_exec_closefrom(3);
} else {
int fd_max = sysconf(_SC_OPEN_MAX);
for(i = 3; i < fd_max; i++)
close(i);
}
if (cwd) {
if (chdir(cwd) < 0)
_exit(127);