From 0916df99511d6918ea905c2a9df45bccc1fd332a Mon Sep 17 00:00:00 2001
From: Paige Sun <paigesun@fb.com>
Date: Wed, 20 Apr 2022 10:59:57 -0700
Subject: [PATCH] Add MC to test disabling React Native invalidation under
 memory pressure

Summary: Changelog: [Internal]

Reviewed By: mdvacca

Differential Revision: D35732504

fbshipit-source-id: d81d6ddefc98d1e73be697c3eef8a2c90104658c
---
 React/Base/RCTConstants.h       | 12 ++++++++++++
 React/Base/RCTConstants.m       | 31 +++++++++++++++++++++++++++++++
 React/CxxBridge/RCTCxxBridge.mm |  3 ++-
 3 files changed, 45 insertions(+), 1 deletion(-)

diff --git a/React/Base/RCTConstants.h b/React/Base/RCTConstants.h
index cc51b2e780f..30bb6eedef5 100644
--- a/React/Base/RCTConstants.h
+++ b/React/Base/RCTConstants.h
@@ -21,3 +21,15 @@ RCT_EXTERN void RCTExperimentSetPreemptiveViewAllocationDisabled(BOOL value);
  */
 RCT_EXTERN BOOL RCTGetDispatchW3CPointerEvents(void);
 RCT_EXTERN void RCTSetDispatchW3CPointerEvents(BOOL value);
+
+/*
+ * Memory Pressure Unloading
+ */
+RCT_EXTERN BOOL RCTGetDisableBridgeMemoryPressureUnload(void);
+RCT_EXTERN void RCTSetDisableBridgeMemoryPressureUnload(BOOL value);
+
+/*
+ * Memory Pressure Unloading Level
+ */
+RCT_EXTERN BOOL RCTGetMemoryPressureUnloadLevel(void);
+RCT_EXTERN void RCTSetMemoryPressureUnloadLevel(int value);
diff --git a/React/Base/RCTConstants.m b/React/Base/RCTConstants.m
index 75b76d708f7..707818cea0c 100644
--- a/React/Base/RCTConstants.m
+++ b/React/Base/RCTConstants.m
@@ -39,3 +39,34 @@ void RCTSetDispatchW3CPointerEvents(BOOL value)
 {
   RCTDispatchW3CPointerEvents = value;
 }
+
+/*
+ * Memory Pressure Unloading
+ */
+static BOOL RCTDisableBridgeMemoryPressureUnload = NO;
+
+BOOL RCTGetDisableBridgeMemoryPressureUnload()
+{
+  return RCTDisableBridgeMemoryPressureUnload;
+}
+
+void RCTSetDisableBridgeMemoryPressureUnload(BOOL value)
+{
+  RCTDisableBridgeMemoryPressureUnload = value;
+}
+
+/*
+ * Memory Pressure Unloading Level for experimentation only.
+ * Default is 15, which is TRIM_MEMORY_RUNNING_CRITICAL.
+ */
+static int RCTMemoryPressureUnloadLevel = 15;
+
+BOOL RCTGetMemoryPressureUnloadLevel()
+{
+  return RCTMemoryPressureUnloadLevel;
+}
+
+void RCTSetMemoryPressureUnloadLevel(int value)
+{
+  RCTMemoryPressureUnloadLevel = value;
+}
diff --git a/React/CxxBridge/RCTCxxBridge.mm b/React/CxxBridge/RCTCxxBridge.mm
index 2454980a9bb..cad9d74f02b 100644
--- a/React/CxxBridge/RCTCxxBridge.mm
+++ b/React/CxxBridge/RCTCxxBridge.mm
@@ -359,7 +359,8 @@ struct RCTInstanceCallback : public InstanceCallback {
   // in case if some other tread resets it.
   auto reactInstance = _reactInstance;
   if (reactInstance) {
-    reactInstance->handleMemoryPressure(15 /* TRIM_MEMORY_RUNNING_CRITICAL */);
+    int unloadLevel = RCTGetMemoryPressureUnloadLevel();
+    reactInstance->handleMemoryPressure(unloadLevel);
   }
 }