From f3da3499c5b2a2a58bdc85f33dd5886f49704932 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Donny/=EA=B0=95=EB=8F=99=EC=9C=A4?= <kdy1997.dev@gmail.com>
Date: Tue, 8 Mar 2022 07:36:06 +0900
Subject: [PATCH] perf(es): Add fast memory deallocator (#3910)

---
 Cargo.lock                                   |  8 ++
 crates/fastmem/Cargo.toml                    | 14 +++
 crates/fastmem/src/fast_drop.rs              | 97 ++++++++++++++++++++
 crates/fastmem/src/lib.rs                    | 14 +++
 crates/swc_ecma_parser/scripts/instrument.sh |  2 +-
 crates/swc_node_base/Cargo.toml              |  1 +
 6 files changed, 135 insertions(+), 1 deletion(-)
 create mode 100644 crates/fastmem/Cargo.toml
 create mode 100644 crates/fastmem/src/fast_drop.rs
 create mode 100644 crates/fastmem/src/lib.rs

diff --git a/Cargo.lock b/Cargo.lock
index 310f879ed36..111caa64934 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -773,6 +773,13 @@ version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4443176a9f2c162692bd3d352d745ef9413eec5782a80d8fd6f8a1ac692a07f7"
 
+[[package]]
+name = "fastmem"
+version = "0.1.0"
+dependencies = [
+ "rayon",
+]
+
 [[package]]
 name = "fixedbitset"
 version = "0.2.0"
@@ -3574,6 +3581,7 @@ dependencies = [
 name = "swc_node_base"
 version = "0.5.1"
 dependencies = [
+ "fastmem",
  "mimalloc-rust",
 ]
 
diff --git a/crates/fastmem/Cargo.toml b/crates/fastmem/Cargo.toml
new file mode 100644
index 00000000000..6b233d94e1f
--- /dev/null
+++ b/crates/fastmem/Cargo.toml
@@ -0,0 +1,14 @@
+[package]
+authors = ["강동윤 <kdy1997.dev@gmail.com>"]
+description = "Configurable utilities for fast memory operations"
+edition = "2021"
+license = "Apache-2.0"
+name = "fastmem"
+repository = "https://github.com/swc-project/swc.git"
+version = "0.1.0"
+
+[features]
+enable = ["rayon"]
+
+[dependencies]
+rayon = {version = "1", optional = true}
diff --git a/crates/fastmem/src/fast_drop.rs b/crates/fastmem/src/fast_drop.rs
new file mode 100644
index 00000000000..e147e6fed63
--- /dev/null
+++ b/crates/fastmem/src/fast_drop.rs
@@ -0,0 +1,97 @@
+use std::ops::{Deref, DerefMut};
+
+pub fn drop_fast<T>(v: T)
+where
+    T: Send + 'static,
+{
+    FastDrop::new(v);
+}
+
+/// Utility type to deallocate memory in another thread.
+///
+///
+///
+/// If ths feature `enable` is turned on, the value will be deallocated in other
+/// thread.
+///
+/// This type uses [rayon::spawn]
+#[repr(transparent)]
+#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub struct FastDrop<T>
+where
+    T: Send + 'static,
+{
+    value: Option<T>,
+}
+
+impl<T> Default for FastDrop<T>
+where
+    T: Send + 'static,
+    T: Default,
+{
+    #[inline(always)]
+    fn default() -> Self {
+        Self::new(T::default())
+    }
+}
+
+impl<T> FastDrop<T>
+where
+    T: Send,
+{
+    #[inline(always)]
+    pub fn new(value: T) -> Self {
+        let value = Some(value);
+        Self { value }
+    }
+}
+
+impl<T> From<T> for FastDrop<T>
+where
+    T: Send,
+{
+    #[inline(always)]
+    fn from(value: T) -> Self {
+        Self::new(value)
+    }
+}
+
+impl<T> Deref for FastDrop<T>
+where
+    T: Send,
+{
+    type Target = T;
+
+    #[inline(always)]
+    fn deref(&self) -> &Self::Target {
+        debug_assert!(self.value.is_some());
+        // Safety: self.value can be None only if drop is called.
+        unsafe { self.value.as_ref().unwrap_unchecked() }
+    }
+}
+
+impl<T> DerefMut for FastDrop<T>
+where
+    T: Send,
+{
+    #[inline(always)]
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        debug_assert!(self.value.is_some());
+        // Safety: self.value can be None only if drop is called.
+        unsafe { self.value.as_mut().unwrap_unchecked() }
+    }
+}
+
+impl<T> Drop for FastDrop<T>
+where
+    T: Send,
+{
+    fn drop(&mut self) {
+        #[cfg(feature = "enable")]
+        if let Some(value) = self.value.take() {
+            rayon::spawn(move || {
+                std::mem::drop(value);
+            });
+        }
+    }
+}
diff --git a/crates/fastmem/src/lib.rs b/crates/fastmem/src/lib.rs
new file mode 100644
index 00000000000..fe6d07af04d
--- /dev/null
+++ b/crates/fastmem/src/lib.rs
@@ -0,0 +1,14 @@
+//! Utilities to unblock main thread.
+//!
+//! # Cargo Features
+//!
+//! ## `enable`
+//!
+//! This enables fast-mode of this crate.
+
+#![deny(clippy::all)]
+#![deny(unused)]
+
+pub use self::fast_drop::*;
+
+mod fast_drop;
diff --git a/crates/swc_ecma_parser/scripts/instrument.sh b/crates/swc_ecma_parser/scripts/instrument.sh
index bc6c85399a7..8b8c35fd582 100755
--- a/crates/swc_ecma_parser/scripts/instrument.sh
+++ b/crates/swc_ecma_parser/scripts/instrument.sh
@@ -1,4 +1,4 @@
 #!/usr/bin/env bash
 set -eu
 
-cargo profile instruments --release -t time --features tracing/release_max_level_info --features swc_common/concurrent --features swc_common/parking_lot --bench parser -- --bench
\ No newline at end of file
+cargo profile instruments --release -t time --features tracing/release_max_level_info --features swc_common/concurrent --features swc_common/parking_lot --bench parser -- --bench
diff --git a/crates/swc_node_base/Cargo.toml b/crates/swc_node_base/Cargo.toml
index f5ee4963e2a..93c1f45a874 100644
--- a/crates/swc_node_base/Cargo.toml
+++ b/crates/swc_node_base/Cargo.toml
@@ -11,6 +11,7 @@ version = "0.5.1"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+fastmem = {version = "0.1.0", path = "../fastmem", features = ["enable"]}
 
 [target.'cfg(not(all(target_os = "linux", target_arch = "aarch64", target_env = "musl")))'.dependencies]
 mimalloc-rust = "=0.1.5"