From 62f2eb908c6771f9ac89aa518c55fbc101df3447 Mon Sep 17 00:00:00 2001
From: Star Rauchenberger <fefferburbia@gmail.com>
Date: Wed, 18 Dec 2024 14:13:39 -0500
Subject: Handle exceptions when starting IPC connection

Also fixes bug where the IPC thread would double-lock the state mutex if the connection timed out and reached the maximum backoff interval.
---
 src/ipc_state.cpp | 68 +++++++++++++++++++++++++++++++++----------------------
 1 file changed, 41 insertions(+), 27 deletions(-)

(limited to 'src')

diff --git a/src/ipc_state.cpp b/src/ipc_state.cpp
index 24d0115..62b1828 100644
--- a/src/ipc_state.cpp
+++ b/src/ipc_state.cpp
@@ -112,8 +112,6 @@ struct IPCState {
  private:
   void Thread() {
     for (;;) {
-      SetStatusMessage("Disconnected from game.");
-
       // initialized is definitely true because it is set to true when the thread
       // is created and only set to false within this block, when the thread is
       // killed. Thus, a call to Connect would always at most set
@@ -127,6 +125,8 @@ struct IPCState {
       {
         std::lock_guard state_guard(state_mutex);
 
+        SetStatusMessage("Disconnected from game.");
+
         should_disconnect = false;
 
         slot_matches = false;
@@ -142,34 +142,49 @@ struct IPCState {
         }
 
         ipc_address = address;
+
+        SetStatusMessage("Connecting to game...");
       }
 
       int backoff_amount = 0;
 
-      SetStatusMessage("Connecting to game...");
       TrackerLog(fmt::format("Looking for game over IPC ({})...", ipc_address));
 
-      while (!TryConnect(ipc_address) || !connected) {
-        int backoff_limit = (backoff_amount + 1) * 10;
-
-        for (int i = 0; i < backoff_limit && !connected; i++) {
-          // If Connect is called right before this block, we will see and handle
-          // should_disconnect. If it is called right after, we will do one bad
-          // poll, one sleep, and then grab the mutex again right after.
-          {
-            std::lock_guard state_guard(state_mutex);
-            if (should_disconnect) {
-              break;
+      while (!connected) {
+        if (TryConnect(ipc_address)) {
+          int backoff_limit = (backoff_amount + 1) * 10;
+
+          for (int i = 0; i < backoff_limit && !connected; i++) {
+            // If Connect is called right before this block, we will see and
+            // handle should_disconnect. If it is called right after, we will do
+            // one bad poll, one sleep, and then grab the mutex again right
+            // after.
+            {
+              std::lock_guard state_guard(state_mutex);
+              if (should_disconnect) {
+                break;
+              }
             }
+
+            ws->poll();
+
+            // Back off
+            std::this_thread::sleep_for(std::chrono::milliseconds(100));
           }
 
-          ws->poll();
+          backoff_amount++;
+        } else {
+          std::lock_guard state_guard(state_mutex);
 
-          // Back off
-          std::this_thread::sleep_for(std::chrono::milliseconds(100));
-        }
+          if (!should_disconnect) {
+            should_disconnect = true;
+            address.clear();
 
-        backoff_amount++;
+            SetStatusMessage("Disconnected from game.");
+          }
+
+          break;
+        }
 
         // If Connect is called right before this block, we will see and handle
         // should_disconnect. If it is called right after, and the connection
@@ -236,6 +251,8 @@ struct IPCState {
           [this](const std::string& s) { OnError(s); });
       return true;
     } catch (const std::exception& ex) {
+      TrackerLog(fmt::format("Error connecting to Lingo: {}", ex.what()));
+      wxMessageBox(ex.what(), "Error connecting to Lingo", wxOK | wxICON_ERROR);
       ws.reset();
       return false;
     }
@@ -303,26 +320,23 @@ struct IPCState {
 
   void OnError(const std::string& s) {}
 
+  // Assumes mutex is locked.
   void CheckIfSlotMatches() {
     slot_matches = (tracker_ap_server == game_ap_server &&
                     tracker_ap_user == game_ap_user);
 
     if (slot_matches) {
-      status_message = "Connected to game.";
+      SetStatusMessage("Connected to game.");
 
       Sync();
     } else if (connected) {
-      status_message = "Local game doesn't match AP slot.";
+      SetStatusMessage("Local game doesn't match AP slot.");
     }
-
-    tracker_frame->UpdateStatusMessage();
   }
 
+  // Assumes mutex is locked.
   void SetStatusMessage(std::optional<std::string> msg) {
-    {
-      std::lock_guard state_guard(state_mutex);
-      status_message = msg;
-    }
+    status_message = msg;
 
     tracker_frame->UpdateStatusMessage();
   }
-- 
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