Fix cleanup deadlock with pending HTTP requests (#930) (#934)

* Fix cleanup deadlock caused by re-entrant lock during HTTP request cancellation

When HCCleanupAsync cancels pending HTTP requests via XAsyncCancel(), the AsyncState
destructor can be invoked synchronously, which attempts to re-acquire the NetworkState
lock (m_mutex) that is already held by CleanupAsyncProvider.

This manifests as a deadlock when cleanup is called with active HTTP requests that have
pending retries. The fix snapshots the active requests while holding the lock, then
releases the lock before calling XAsyncCancel() to avoid re-entrant lock acquisition.

Also applies the same pattern to connected websocket disconnection for consistency.

Fixes deadlock in TestAsyncCleanupWithHttpCallPendingRetry.

* Use xbox:hc:Vector in fix for proper allocation hooking

Previous commit used std::vector, which bypasses the LHC allocation hook

---------

Co-authored-by: Jason Sandlin <jasonsa@microsoft.com>

Author: jhugard

Source/Global/NetworkState.cpp

@@ -376,19 +376,31 @@ HRESULT CALLBACK NetworkState::CleanupAsyncProvider(XAsyncOp op, const XAsyncPro
     {
     case XAsyncOp::Begin:
     {
-        std::unique_lock<std::mutex> lock{ state->m_mutex };
-        state->m_cleanupAsyncBlock = data->async;
-        bool scheduleCleanup = state->ScheduleCleanup();
+        xbox::httpclient::Vector<XAsyncBlock*> activeRequests;
+#ifndef HC_NOWEBSOCKETS
+        xbox::httpclient::Vector<ActiveWebSocketContext*> connectedWebSockets;
+#endif
+        bool scheduleCleanup = false;
+        {
+            std::unique_lock<std::mutex> lock{ state->m_mutex };
+            state->m_cleanupAsyncBlock = data->async;
+            scheduleCleanup = state->ScheduleCleanup();
 
+#ifndef HC_NOWEBSOCKETS 
+            HC_TRACE_VERBOSE(HTTPCLIENT, "NetworkState::CleanupAsyncProvider::Begin: HTTP active=%llu, WebSocket Connecting=%llu, WebSocket Connected=%llu", state->m_activeHttpRequests.size(), state->m_connectingWebSockets.size(), state->m_connectedWebSockets.size());
+#endif
+            activeRequests.assign(state->m_activeHttpRequests.begin(), state->m_activeHttpRequests.end());
 #ifndef HC_NOWEBSOCKETS
-        HC_TRACE_VERBOSE(HTTPCLIENT, "NetworkState::CleanupAsyncProvider::Begin: HTTP active=%llu, WebSocket Connecting=%llu, WebSocket Connected=%llu", state->m_activeHttpRequests.size(), state->m_connectingWebSockets.size(), state->m_connectedWebSockets.size());
+            connectedWebSockets.assign(state->m_connectedWebSockets.begin(), state->m_connectedWebSockets.end());
 #endif
-        for (auto& activeRequest : state->m_activeHttpRequests)
+        }
+
+        for (auto& activeRequest : activeRequests)
         {
             XAsyncCancel(activeRequest);
         }
 #ifndef HC_NOWEBSOCKETS
-        for (auto& context : state->m_connectedWebSockets)
+        for (auto& context : connectedWebSockets)
         {
             HRESULT hr = context->websocketObserver->websocket->Disconnect();
             if (FAILED(hr))
@@ -397,7 +409,6 @@ HRESULT CALLBACK NetworkState::CleanupAsyncProvider(XAsyncOp op, const XAsyncPro
             }
         }
 #endif
-        lock.unlock();
 
         if (scheduleCleanup)
         {