use weak ptr of base wasm handle

本次代码评审主要涉及将`base_wasm_handle_`从一个直接的`std::shared_ptr`更改为`std::weak_ptr`（命名为`base_wasm_handle_weak_`），并在访问时增加检查以确保弱引用未失效，增强了内存管理的安全性，避免了潜在的空指针异常。
Link: https://code.alibaba-inc.com/Ingress/proxy-wasm-cpp-host/codereview/18296840
* use weak ptr of base wasm handle

* fix typo

* fix typo

Author: johnlanni

include/proxy-wasm/wasm.h

@@ -305,7 +305,7 @@ class WasmBase : public std::enable_shared_from_this<WasmBase> {
   // is not enforced.
   AllowedCapabilitiesMap allowed_capabilities_;
 
-  std::shared_ptr<WasmHandleBase> base_wasm_handle_;
+  std::weak_ptr<WasmHandleBase> base_wasm_handle_weak_;
 
   // Used by the base_wasm to enable non-clonable thread local Wasm(s) to be constructed.
   std::string module_bytecode_;
@@ -448,8 +448,9 @@ std::shared_ptr<PluginHandleBase> getOrCreateThreadLocalPlugin(
 void clearWasmCachesForTesting();
 
 inline const std::string &WasmBase::vm_configuration() const {
-  if (base_wasm_handle_)
-    return base_wasm_handle_->wasm()->vm_configuration_;
+  auto base_wasm_handle = base_wasm_handle_weak_.lock();
+  if (base_wasm_handle)
+    return base_wasm_handle->wasm()->vm_configuration_;
   return vm_configuration_;
 }
 

src/wasm.cc

@@ -200,7 +200,7 @@ WasmBase::WasmBase(const std::shared_ptr<WasmHandleBase> &base_wasm_handle,
       started_from_(base_wasm_handle->wasm()->wasm_vm()->cloneable()),
       envs_(base_wasm_handle->wasm()->envs()),
       allowed_capabilities_(base_wasm_handle->wasm()->allowed_capabilities_),
-      base_wasm_handle_(base_wasm_handle) {
+      base_wasm_handle_weak_(base_wasm_handle) {
   if (started_from_ != Cloneable::NotCloneable) {
     wasm_vm_ = base_wasm_handle->wasm()->wasm_vm()->clone();
   } else {
@@ -317,17 +317,27 @@ bool WasmBase::initialize() {
   }
 
   if (started_from_ == Cloneable::NotCloneable) {
-    auto ok = wasm_vm_->load(base_wasm_handle_->wasm()->moduleBytecode(),
-                             base_wasm_handle_->wasm()->modulePrecompiled(),
-                             base_wasm_handle_->wasm()->functionNames());
+    auto base_wasm_handle = base_wasm_handle_weak_.lock();
+    if (!base_wasm_handle) {
+      fail(FailState::UnableToInitializeCode, "Base wasm handle is null");
+      return false;
+    }
+    auto ok = wasm_vm_->load(base_wasm_handle->wasm()->moduleBytecode(),
+                             base_wasm_handle->wasm()->modulePrecompiled(),
+                             base_wasm_handle->wasm()->functionNames());
     if (!ok) {
       fail(FailState::UnableToInitializeCode, "Failed to load Wasm module from base Wasm");
       return false;
     }
   }
 
   if (started_from_.has_value()) {
-    abi_version_ = base_wasm_handle_->wasm()->abiVersion();
+    auto base_wasm_handle = base_wasm_handle_weak_.lock();
+    if (!base_wasm_handle) {
+      fail(FailState::UnableToInitializeCode, "Base wasm handle is null");
+      return false;
+    }
+    abi_version_ = base_wasm_handle->wasm()->abiVersion();
   }
 
   if (started_from_ != Cloneable::InstantiatedModule) {