From 9ce90315ab53cf8505c201e398d883d2ed6418da Mon Sep 17 00:00:00 2001
From: khanhduytran0 <khanhduytran0@users.noreply.github.com>
Date: Wed, 16 Apr 2025 18:28:35 +0700
Subject: [PATCH] Feat: pre-validate if there is sufficient memory

---
 Natives/JavaLauncher.m | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/Natives/JavaLauncher.m b/Natives/JavaLauncher.m
index c46bd5a4..50a3510c 100644
--- a/Natives/JavaLauncher.m
+++ b/Natives/JavaLauncher.m
@@ -20,6 +20,14 @@
 
 extern char **environ;
 
+BOOL validateVirtualMemorySpace(int size) {
+    void *map = mmap(0, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+    // check if process successfully maps and unmaps a contiguous range
+    if(map == MAP_FAILED || munmap(map, size) != 0)
+        return NO;
+    return YES;
+}
+
 void init_loadDefaultEnv() {
     /* Define default env */
 
@@ -167,6 +175,11 @@ int launchJVM(NSString *username, id launchTarget, int width, int height, int mi
         allocmem = getPrefInt(@"java.allocated_memory");
     }
     NSLog(@"[JavaLauncher] Max RAM allocation is set to %d MB", allocmem);
+    if (!validateVirtualMemorySpace(allocmem)) {
+        UIKit_returnToSplitView();
+        showDialog(localize(@"Error", nil), @"Insufficient contiguous virtual memory space. Lower memory allocation and try again.");
+        return 1;
+    }
 
     int margc = -1;
     const char *margv[1000];