From 43bf393dbf13d6a877e45c890447e2693f60e8c5 Mon Sep 17 00:00:00 2001
From: h2zero <32826625+h2zero@users.noreply.github.com>
Date: Sat, 11 May 2019 02:03:09 -0600
Subject: [PATCH] Fix semaphores in IDF & std::string assert (#2728)

* Fix semaphores in IDF & std::string assert

Fixes the problem of giving a mutex from a callback with the latest IDF. Also addresses an occasional assert that happens when the btc_task callback gives the semaphore and causes an assert due to both cores potentially writing m_owner concurrently.

* Restored m_owner position in wait() as requested

* Reapply assert fix and move setting m_owner in ::give()

Revert previous revert commit and move setting of m_owner in ::give to before giving the semaphore to prevent race condition possibility.
---
 libraries/BLE/src/FreeRTOS.cpp | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/libraries/BLE/src/FreeRTOS.cpp b/libraries/BLE/src/FreeRTOS.cpp
index a5f5ff72..9f4c1995 100644
--- a/libraries/BLE/src/FreeRTOS.cpp
+++ b/libraries/BLE/src/FreeRTOS.cpp
@@ -61,15 +61,13 @@ uint32_t FreeRTOS::getTimeSinceStart() {
  */
 uint32_t FreeRTOS::Semaphore::wait(std::string owner) {
 	log_v(">> wait: Semaphore waiting: %s for %s", toString().c_str(), owner.c_str());
-
+	
 	if (m_usePthreads) {
 		pthread_mutex_lock(&m_pthread_mutex);
 	} else {
 		xSemaphoreTake(m_semaphore, portMAX_DELAY);
 	}
 
-	m_owner = owner;
-
 	if (m_usePthreads) {
 		pthread_mutex_unlock(&m_pthread_mutex);
 	} else {
@@ -77,7 +75,6 @@ uint32_t FreeRTOS::Semaphore::wait(std::string owner) {
 	}
 
 	log_v("<< wait: Semaphore released: %s", toString().c_str());
-	m_owner = std::string("<N/A>");
 	return m_value;
 } // wait
 
@@ -87,7 +84,8 @@ FreeRTOS::Semaphore::Semaphore(std::string name) {
 	if (m_usePthreads) {
 		pthread_mutex_init(&m_pthread_mutex, nullptr);
 	} else {
-		m_semaphore = xSemaphoreCreateMutex();
+		m_semaphore = xSemaphoreCreateBinary();
+		xSemaphoreGive(m_semaphore);
 	}
 
 	m_name      = name;
@@ -111,6 +109,8 @@ FreeRTOS::Semaphore::~Semaphore() {
  */
 void FreeRTOS::Semaphore::give() {
 	log_v("Semaphore giving: %s", toString().c_str());
+	m_owner = std::string("<N/A>");
+	
 	if (m_usePthreads) {
 		pthread_mutex_unlock(&m_pthread_mutex);
 	} else {
@@ -120,7 +120,6 @@ void FreeRTOS::Semaphore::give() {
 // 	FreeRTOS::sleep(10);
 // #endif
 
-	m_owner = std::string("<N/A>");
 } // Semaphore::give