From 8513c8fa69171a6721cb3474080af58e1b56aae2 Mon Sep 17 00:00:00 2001
From: Moritz Gunz <moritz.gunz@gmail.com>
Date: Mon, 7 Sep 2020 12:00:35 +0100
Subject: [PATCH] Add bindings to 'v8::Isolate::LowMemoryNotification()' (#459)

---
 src/binding.cc    | 4 ++++
 src/isolate.rs    | 7 +++++++
 tests/test_api.rs | 6 ++++++
 3 files changed, 17 insertions(+)

diff --git a/src/binding.cc b/src/binding.cc
index 4011b067..355793c7 100644
--- a/src/binding.cc
+++ b/src/binding.cc
@@ -119,6 +119,10 @@ void v8__Isolate__Enter(v8::Isolate* isolate) { isolate->Enter(); }
 
 void v8__Isolate__Exit(v8::Isolate* isolate) { isolate->Exit(); }
 
+void v8__Isolate__LowMemoryNotification(v8::Isolate* isolate) {
+  isolate->LowMemoryNotification();
+}
+
 void v8__Isolate__GetHeapStatistics(v8::Isolate* isolate,
                                     v8::HeapStatistics* s) {
   isolate->GetHeapStatistics(s);
diff --git a/src/isolate.rs b/src/isolate.rs
index 4a4626c8..f6753b29 100644
--- a/src/isolate.rs
+++ b/src/isolate.rs
@@ -105,6 +105,7 @@ extern "C" {
   fn v8__Isolate__GetNumberOfDataSlots(this: *const Isolate) -> u32;
   fn v8__Isolate__Enter(this: *mut Isolate);
   fn v8__Isolate__Exit(this: *mut Isolate);
+  fn v8__Isolate__LowMemoryNotification(isolate: *mut Isolate);
   fn v8__Isolate__GetHeapStatistics(this: *mut Isolate, s: *mut HeapStatistics);
   fn v8__Isolate__SetCaptureStackTraceForUncaughtExceptions(
     this: *mut Isolate,
@@ -366,6 +367,12 @@ impl Isolate {
     unsafe { v8__Isolate__Exit(self) }
   }
 
+  /// Optional notification that the system is running low on memory.
+  /// V8 uses these notifications to attempt to free memory.
+  pub fn low_memory_notification(&mut self) {
+    unsafe { v8__Isolate__LowMemoryNotification(self) }
+  }
+
   /// Get statistics about the heap memory usage.
   pub fn get_heap_statistics(&mut self, s: &mut HeapStatistics) {
     unsafe { v8__Isolate__GetHeapStatistics(self, s) }
diff --git a/tests/test_api.rs b/tests/test_api.rs
index ea97d898..46a258d2 100644
--- a/tests/test_api.rs
+++ b/tests/test_api.rs
@@ -3414,6 +3414,12 @@ fn heap_statistics() {
   assert_ne!(s.number_of_native_contexts(), 0);
 }
 
+#[test]
+fn low_memory_notification() {
+  let mut isolate = v8::Isolate::new(Default::default());
+  isolate.low_memory_notification();
+}
+
 fn synthetic_evaluation_steps<'a>(
   context: v8::Local<'a, v8::Context>,
   module: v8::Local<v8::Module>,