From d85852ea510d50e2d0d5634eba264f12b8d45984 Mon Sep 17 00:00:00 2001
From: Wolfgang Hottgenroth <w.hottgenroth@krohne.com>
Date: Fri, 4 Oct 2019 14:48:57 +0200
Subject: [PATCH] protect counter variables

---
 snippets/test1/test1.c | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/snippets/test1/test1.c b/snippets/test1/test1.c
index fbd0f5a..aaf302a 100644
--- a/snippets/test1/test1.c
+++ b/snippets/test1/test1.c
@@ -65,6 +65,7 @@ uint32_t counter = 0;
 uint32_t diff = 0;
 
 
+pthread_mutex_t counterMutex = PTHREAD_MUTEX_INITIALIZER;
 pthread_mutex_t eventMutex = PTHREAD_MUTEX_INITIALIZER;
 pthread_cond_t eventSignal = PTHREAD_COND_INITIALIZER;
 
@@ -101,11 +102,14 @@ void isr() {
 
   uint32_t currentCounter = read32(CMD_RD | REG_OTR);
 
+  pthread_mutex_lock(&counterMutex);
   diff = currentCounter - lastCounter;
   counter = currentCounter;
-  lastCounter = currentCounter;
-
   ec++;
+  pthread_mutex_unlock(&counterMutex);
+
+
+  lastCounter = currentCounter;
   
   pthread_mutex_lock(&eventMutex);
   pthread_cond_signal(&eventSignal);
@@ -132,6 +136,9 @@ void initCounter() {
 
 int main (void) {
   static uint32_t lastDiff = 0;
+  uint32_t my_ec = 0;
+  uint32_t my_counter = 0;
+  uint32_t my_diff = 0;
 
   init();
   initCounter();
@@ -141,6 +148,12 @@ int main (void) {
     pthread_cond_wait(&eventSignal, &eventMutex);
     pthread_mutex_unlock(&eventMutex);
 
+    pthread_mutex_lock(&counterMutex);
+    my_ec = ec;
+    my_counter = counter;
+    my_diff = diff;
+    pthread_mutex_unlock(&counterMutex);
+
     if (diff != lastDiff) {
       lastDiff = diff;
       double f = 1.0 / (((double) diff) / 1000000.0);