From 630bbfca91de1c5568fd4bd5cd18e1c5d4ef55ef Mon Sep 17 00:00:00 2001
From: Jarred Sumner <jarred@jarredsumner.com>
Date: Mon, 18 Sep 2023 00:11:18 -0700
Subject: [PATCH] Add a way to disable the GC timer (#5656)

Co-authored-by: Jarred Sumner <709451+Jarred-Sumner@users.noreply.github.com>
---
 src/bun.js/event_loop.zig | 12 ++++++++++--
 src/env_loader.zig        |  7 +++++++
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/src/bun.js/event_loop.zig b/src/bun.js/event_loop.zig
index 724839ebc6..7f175a1a11 100644
--- a/src/bun.js/event_loop.zig
+++ b/src/bun.js/event_loop.zig
@@ -455,6 +455,7 @@ pub const GarbageCollectionController = struct {
     gc_repeating_timer: *uws.Timer = undefined,
     gc_timer_interval: i32 = 0,
     gc_repeating_timer_fast: bool = true,
+    disabled: bool = false,
 
     pub fn init(this: *GarbageCollectionController, vm: *VirtualMachine) void {
         var actual = vm.event_loop_handle.?;
@@ -469,8 +470,12 @@ pub const GarbageCollectionController = struct {
                 }
             } else |_| {}
         }
-        this.gc_repeating_timer.set(this, onGCRepeatingTimer, gc_timer_interval, gc_timer_interval);
         this.gc_timer_interval = gc_timer_interval;
+
+        this.disabled = vm.bundler.env.has("BUN_GC_TIMER_DISABLE");
+
+        if (!this.disabled)
+            this.gc_repeating_timer.set(this, onGCRepeatingTimer, gc_timer_interval, gc_timer_interval);
     }
 
     pub fn scheduleGCTimer(this: *GarbageCollectionController) void {
@@ -484,6 +489,7 @@ pub const GarbageCollectionController = struct {
 
     pub fn onGCTimer(timer: *uws.Timer) callconv(.C) void {
         var this = timer.as(*GarbageCollectionController);
+        if (this.disabled) return;
         this.gc_timer_state = .run_on_next_tick;
     }
 
@@ -528,11 +534,12 @@ pub const GarbageCollectionController = struct {
     }
 
     pub fn processGCTimer(this: *GarbageCollectionController) void {
+        if (this.disabled) return;
         var vm = this.bunVM().global.vm();
         this.processGCTimerWithHeapSize(vm, vm.blockBytesAllocated());
     }
 
-    pub fn processGCTimerWithHeapSize(this: *GarbageCollectionController, vm: *JSC.VM, this_heap_size: usize) void {
+    fn processGCTimerWithHeapSize(this: *GarbageCollectionController, vm: *JSC.VM, this_heap_size: usize) void {
         const prev = this.gc_last_heap_size;
 
         switch (this.gc_timer_state) {
@@ -568,6 +575,7 @@ pub const GarbageCollectionController = struct {
     }
 
     pub fn performGC(this: *GarbageCollectionController) void {
+        if (this.disabled) return;
         var vm = this.bunVM().global.vm();
         vm.collectAsync();
         this.gc_last_heap_size = vm.blockBytesAllocated();
diff --git a/src/env_loader.zig b/src/env_loader.zig
index 2d467371ae..b8fa90d453 100644
--- a/src/env_loader.zig
+++ b/src/env_loader.zig
@@ -37,6 +37,13 @@ pub const Loader = struct {
 
     const empty_string_value: string = "\"\"";
 
+    pub fn has(this: *const Loader, input: []const u8) bool {
+        const value = this.map.get(input) orelse return false;
+        if (value.len == 0) return false;
+
+        return !strings.eqlComptime(value, "\"\"") and !strings.eqlComptime(value, "''") and !strings.eqlComptime(value, "0") and !strings.eqlComptime(value, "false");
+    }
+
     pub fn isProduction(this: *const Loader) bool {
         const env = this.map.get("BUN_ENV") orelse this.map.get("NODE_ENV") orelse return false;
         return strings.eqlComptime(env, "production");