From 8bd4aa57839c5cba3f0c7bdcab149e2d76589a95 Mon Sep 17 00:00:00 2001
From: Valery Antopol <valery.antopol@gmail.com>
Date: Fri, 8 Jul 2022 17:29:26 +0300
Subject: [PATCH] Add a workaround for wasm memory leak (#282)

* Add a workaround for wasm memory leak

* fmt
---
 air-interpreter/src/marine.rs | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/air-interpreter/src/marine.rs b/air-interpreter/src/marine.rs
index 27d5f072..98fa249d 100644
--- a/air-interpreter/src/marine.rs
+++ b/air-interpreter/src/marine.rs
@@ -37,7 +37,29 @@ use marine_rs_sdk::module_manifest;
 
 module_manifest!();
 
+/*
+   _initialize function that calls __wasm_call_ctors is required to mitigate memory leak
+   that is described in https://github.com/WebAssembly/wasi-libc/issues/298.
+
+   In short, without this code rust wraps every export function
+   with __wasm_call_ctors/__wasm_call_dtors calls. This causes memory leaks. When compiler sees
+   an explicit call to __wasm_call_ctors in _initialize function, it disables export wrapping.
+
+   TODO: remove when updating to marine-rs-sdk with fix
+*/
+extern "C" {
+    fn __wasm_call_ctors();
+}
+
+#[no_mangle]
+pub fn _initialize() {
+    unsafe {
+        __wasm_call_ctors();
+    }
+}
+
 pub fn main() {
+    _initialize(); // As __wasm_call_ctors still does necessary work, we call it at the start of the module.
     logger::init_logger(None);
 }