fix: Update to new Issue #78 for SocketBox deadlock investigation

- Previous Issue #76 and PR #77 closed and recreated
- New streamlined issue focusing on core deadlock problem
- Multiple Arc<Mutex> hypothesis as primary investigation target
- Ready for systematic root cause analysis

🔥 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

socketbox_issue_new.md

@@ -0,0 +1,154 @@
+# 🚨 SocketBox Method Call Deadlock - Critical System Failure
+
+**Status**: 🔥 **CRITICAL** - Complete SocketBox functionality failure  
+**Impact**: Phase 9 HTTP server implementation completely blocked  
+**Priority**: Immediate investigation required  
+
+## 📋 Problem Summary
+
+All SocketBox methods (`bind()`, `listen()`, `isServer()`, `toString()`) cause infinite blocking/deadlock. Other Box types (StringBox, ArrayBox, MapBox) work normally.
+
+## 🎯 Root Cause Analysis Completed
+
+### ✅ **Confirmed Working Components**
+- SocketBox creation: `new SocketBox()` ✅
+- Arc reference sharing: `Arc addresses match = true` ✅  
+- Clone functionality: Proper Arc<Mutex> sharing ✅
+
+### ❌ **Identified Problem Location**
+```rust
+// src/interpreter/expressions.rs:462-464
+if let Some(socket_box) = obj_value.as_any().downcast_ref::<SocketBox>() {
+    let result = self.execute_socket_method(socket_box, method, arguments)?;
+    // ↑ Never reaches this line - execute_socket_method is never called
+}
+```
+
+**Core Issue**: Deadlock occurs in method resolution pipeline BEFORE execute_socket_method is reached.
+
+## 📊 Evidence from Execution Logs
+
+### 🔥 **Deadlock Reproduction Log**
+```bash
+[Console LOG] SocketBox作成完了
+[Console LOG] bind実行開始...
+🔥 SOCKETBOX CLONE DEBUG: Arc addresses match = true  # ← Clone works fine
+# Infinite block here - 🔥 SOCKET_METHOD: bind() called never appears
+```
+
+### ✅ **Normal Box Comparison (ArrayBox)**
+```bash
+[Console LOG] ArrayBox作成完了  
+[Console LOG] push実行開始...
+✅ ARRAY_METHOD: push() called    # ← Method reached normally
+✅ ArrayBox push completed        # ← Completes successfully
+```
+
+## 🧪 **Reproduction Test Cases**
+
+### **Test 1: Minimal Deadlock Reproduction**
+```bash
+# Command
+timeout 10s ./target/release/nyash test_socket_deadlock_minimal.nyash
+
+# Expected: Timeout (deadlock)
+# Actual Output:
+# [Console LOG] SocketBox作成成功
+# [Console LOG] bind()実行開始...
+# (infinite block)
+```
+
+### **Test 2: Other Boxes Normal Operation**
+```bash  
+# Command
+./target/release/nyash test_other_boxes_working.nyash
+
+# Expected: Normal completion
+# Actual Output:
+# [Console LOG] ✅ ArrayBox正常: size=1
+# [Console LOG] ✅ MapBox正常: value=test_value
+# [Console LOG] 🎉 他のBox全て正常動作: 4件成功
+```
+
+### **Test 3: All SocketBox Methods**
+```bash
+# Command  
+timeout 30s ./target/release/nyash test_socket_methods_comprehensive.nyash
+
+# Expected: Deadlock on first method call
+# All methods (toString, isServer, bind, close) should deadlock
+```
+
+## 🔍 **Technical Investigation Required**
+
+### **Primary Hypothesis**
+SocketBox's unique **multiple Arc<Mutex> combination** causing circular deadlock:
+
+```rust
+// SocketBox structure (PROBLEMATIC)
+pub struct SocketBox {
+    listener: Arc<Mutex<Option<TcpListener>>>,     // Mutex 1
+    stream: Arc<Mutex<Option<TcpStream>>>,         // Mutex 2  
+    is_server: Arc<Mutex<bool>>,                   // Mutex 3
+    is_connected: Arc<Mutex<bool>>,                // Mutex 4
+}
+
+// vs Other Boxes (WORKING)
+StringBox: Arc<String> only                       // No Mutex
+ArrayBox: Arc<Mutex<Vec<T>>> only                 // Single Mutex  
+MapBox: Arc<Mutex<HashMap<K,V>>> only             // Single Mutex
+```
+
+### **Investigation Areas**
+1. **Lock ordering**: Multiple mutex acquisition sequence
+2. **Recursive locking**: Same mutex re-entry during method resolution
+3. **Cross-reference deadlock**: Arc reference cycles
+4. **Interpreter pipeline**: Method resolution vs execution stage bottleneck
+
+## 🎯 **Required Analysis**
+
+### **Systematic Approach Required**
+- **NO band-aid fixes** - Root cause identification essential
+- **NO guesswork solutions** - Evidence-based analysis only
+- **Complete validation** - All test cases must pass
+
+### **Investigation Phases**
+1. **Architecture Level**: Compare SocketBox vs other Box memory/locking patterns
+2. **Runtime Level**: Method resolution pipeline analysis  
+3. **Concurrency Level**: Arc<Mutex> deadlock detection
+4. **Parser/AST Level**: If needed, verify AST generation differences
+
+## 🧪 **Test Files Provided**
+
+All test files are ready for immediate execution:
+- `test_socket_deadlock_minimal.nyash` - Minimal reproduction
+- `test_socket_methods_comprehensive.nyash` - All methods test  
+- `test_other_boxes_working.nyash` - Normal Box operation verification
+- `SOCKETBOX_ISSUE_REPRODUCTION.md` - Complete reproduction guide
+
+## ✅ **Success Criteria**
+
+### **Must Achieve**
+```bash
+# Basic functionality  
+./target/release/nyash test_socket_deadlock_minimal.nyash
+# Expected: Normal completion, no deadlock
+
+# State management
+socket.bind("127.0.0.1", 8080)
+socket.isServer()  # Must return true
+
+# All methods working
+./target/release/nyash test_socket_methods_comprehensive.nyash  
+# Expected: All methods complete successfully
+```
+
+### **Validation Required**
+- **Before/After comparison**: Detailed behavior analysis
+- **Performance impact**: Ensure fix doesn't degrade other functionality
+- **Memory safety**: Maintain Rust safety guarantees
+- **Architecture consistency**: Solution aligns with "Everything is Box" philosophy
+
+---
+
+**🚨 This issue completely blocks Phase 9 HTTP server implementation. Immediate resolution critical.**