From 9509bdcd66c59c7f715774a9434eb39c727039d8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alex=20Villac=C3=ADs=20Lasso?= <a_villacis@palosanto.com>
Date: Sat, 2 Jan 2021 17:43:33 -0500
Subject: [PATCH] Compare task handles instead of opaque undocumented symbols

Based on commit 9b98550f64000b937db9567b69e1275feccf1f0f of dumbfixes
branch of 0xFEEDC0DE64 fork of ESPAsyncWebServer.

The AsyncWebLock class tries to prevent self-deadlock by comparing the
current task with the task currently holding the lock (if any). Use
documented task handle values and APIs instead of grabbing undocumented
external symbols for this.
---
 src/AsyncWebSynchronization.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/AsyncWebSynchronization.h b/src/AsyncWebSynchronization.h
index 0f76815..0591ea1 100644
--- a/src/AsyncWebSynchronization.h
+++ b/src/AsyncWebSynchronization.h
@@ -44,7 +44,7 @@ class AsyncWebLock
 {
 private:
   SemaphoreHandle_t _lock;
-  mutable void *_lockedBy;
+  mutable TaskHandle_t _lockedBy{};
 
 public:
   AsyncWebLock() {
@@ -61,10 +61,10 @@ public:
   }
 
   bool lock() const {
-    extern void *pxCurrentTCB;
-    if (_lockedBy != pxCurrentTCB) {
+    const auto currentTask = xTaskGetCurrentTaskHandle();
+    if (_lockedBy != currentTask) {
       xSemaphoreTake(_lock, portMAX_DELAY);
-      _lockedBy = pxCurrentTCB;
+      _lockedBy = currentTask;
       return true;
     }
     return false;