3 files changed, 45 insertions, 0 deletions
diff --git a/cli/main.rs b/cli/main.rs
index d8e893906..0005bb891 100644
--- a/cli/main.rs
+++ b/cli/main.rs
@@ -36,6 +36,7 @@ mod tokio_util;
 mod tools;
 mod tsc;
 mod tsc_config;
+mod unix_util;
 mod version;
 
 use crate::file_fetcher::File;
@@ -1176,6 +1177,7 @@ fn unwrap_or_exit<T>(result: Result<T, AnyError>) -> T {
 pub fn main() {
   #[cfg(windows)]
   colors::enable_ansi(); // For Windows 10
+  unix_util::raise_fd_limit();
 
   let args: Vec<String> = env::args().collect();
   let standalone_res = match standalone::extract_standalone(args.clone()) {
diff --git a/cli/main_runtime.rs b/cli/main_runtime.rs
index db3f9fd02..23f1c23b6 100644
--- a/cli/main_runtime.rs
+++ b/cli/main_runtime.rs
@@ -5,6 +5,7 @@
 mod colors;
 mod standalone;
 mod tokio_util;
+mod unix_util;
 mod version;
 
 use deno_core::error::anyhow;
@@ -14,6 +15,7 @@ use std::env;
 pub fn main() {
   #[cfg(windows)]
   colors::enable_ansi(); // For Windows 10
+  unix_util::raise_fd_limit();
 
   let args: Vec<String> = env::args().collect();
   if let Err(err) = run(args) {
diff --git a/cli/unix_util.rs b/cli/unix_util.rs
new file mode 100644
index 000000000..4aa8ef55d
--- /dev/null
+++ b/cli/unix_util.rs
@@ -0,0 +1,41 @@
+/// Raise soft file descriptor limit to hard file descriptor limit.
+/// This is the difference between `ulimit -n` and `ulimit -n -H`.
+pub fn raise_fd_limit() {
+  #[cfg(unix)]
+  unsafe {
+    let mut limits = libc::rlimit {
+      rlim_cur: 0,
+      rlim_max: 0,
+    };
+
+    if 0 != libc::getrlimit(libc::RLIMIT_NOFILE, &mut limits) {
+      return;
+    }
+
+    if limits.rlim_cur == libc::RLIM_INFINITY {
+      return;
+    }
+
+    // No hard limit? Do a binary search for the effective soft limit.
+    if limits.rlim_max == libc::RLIM_INFINITY {
+      let mut min = limits.rlim_cur;
+      let mut max = 1 << 20;
+
+      while min + 1 < max {
+        limits.rlim_cur = min + (max - min) / 2;
+        match libc::setrlimit(libc::RLIMIT_NOFILE, &limits) {
+          0 => min = limits.rlim_cur,
+          _ => max = limits.rlim_cur,
+        }
+      }
+
+      return;
+    }
+
+    // Raise the soft limit to the hard limit.
+    if limits.rlim_cur < limits.rlim_max {
+      limits.rlim_cur = limits.rlim_max;
+      libc::setrlimit(libc::RLIMIT_NOFILE, &limits);
+    }
+  }
+}