From 6f7797807c76bcb38b2ff9ab887137256c5018e7 Mon Sep 17 00:00:00 2001
From: Jaakko Korhonen <jaakko.korhonen@arm.com>
Date: Wed, 12 Jul 2017 13:44:45 +0300
Subject: [PATCH 1/3] Added multithreaded lock test.

This should detect issues with uneven locking and releasing.
---
 test/CMakeLists.txt |  2 ++
 test/Test.cpp       | 32 ++++++++++++++++++++++++++++++++
 2 files changed, 34 insertions(+)

diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index d67c574..a3b78b2 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -16,6 +16,8 @@ if(DEFINED TARGET_LIKE_X86_WINDOWS_NATIVE OR DEFINED TARGET_LIKE_X86_LINUX_NATIV
     endif()
     if(DEFINED TARGET_LIKE_X86_LINUX_NATIVE)
         SET(TEST_EXECUTABLE "../../../build/x86-linux-native/test/mbed_trace_test")
+        find_package (Threads)
+        target_link_libraries (mbed_trace_test ${CMAKE_THREAD_LIBS_INIT})
         add_test(mbed_trace_test ${TEST_EXECUTABLE})
         add_dependencies(all_tests mbed_trace_test)
     endif()
diff --git a/test/Test.cpp b/test/Test.cpp
index 52b5934..f2238e7 100644
--- a/test/Test.cpp
+++ b/test/Test.cpp
@@ -9,6 +9,8 @@
 #include <string.h>
 #include <stdlib.h>
 #include <stdint.h>
+#include <pthread.h> /* pthread_create() */
+#include <unistd.h> /* usleep() */
 
 #include "mbed-cpputest/CppUTest/TestHarness.h"
 #include "mbed-cpputest/CppUTest/SimpleString.h"
@@ -474,3 +476,33 @@ TEST(trace, uninitialized)
     STRCMP_EQUAL("hello", buf);
 }
 
+void* multithread_printer(void *ti)
+{
+    volatile int thread_index = *(int *)ti;
+    for(int i=0; i<10; i++) {
+      //printf("thread index = %d, round %d\n", thread_index, i);
+      mbed_tracef(TRACE_LEVEL_DEBUG, "mygr", "thread index = %d, round %d", thread_index, i);
+      usleep(1000 * (1 + thread_index)); /* (1 + thread_index) ms delay */
+    }
+    return NULL;
+}
+
+TEST(trace, multithread)
+{
+    const int thread_amount = 10;
+    pthread_t threads[thread_amount];
+    int thread_indexes[thread_amount];
+
+    for(int j=0; j<10; j++)
+    {
+      for(int i=0; i<(sizeof(threads)/sizeof(pthread_t)); i++) {
+          //printf("creating %d\n", i);
+          thread_indexes[i] = i;
+          pthread_create(&threads[i], NULL, &multithread_printer, (void *)&thread_indexes[i]);
+      }
+      for(int i=0; i<(sizeof(threads)/sizeof(pthread_t)); i++) {
+          //printf("joining %d\n", i);
+          pthread_join(threads[i], NULL);
+      }
+    }
+}

From eedef06037954ba2044ec0b63c03b860881a2cf7 Mon Sep 17 00:00:00 2001
From: Jaakko Korhonen <jaakko.korhonen@arm.com>
Date: Wed, 12 Jul 2017 13:47:31 +0300
Subject: [PATCH 2/3] Modified loops to use thread_mount instead of sizeof()
 calculation.

---
 test/Test.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/test/Test.cpp b/test/Test.cpp
index f2238e7..25f93c7 100644
--- a/test/Test.cpp
+++ b/test/Test.cpp
@@ -495,12 +495,12 @@ TEST(trace, multithread)
 
     for(int j=0; j<10; j++)
     {
-      for(int i=0; i<(sizeof(threads)/sizeof(pthread_t)); i++) {
+      for(int i=0; i<thread_amount; i++) {
           //printf("creating %d\n", i);
           thread_indexes[i] = i;
           pthread_create(&threads[i], NULL, &multithread_printer, (void *)&thread_indexes[i]);
       }
-      for(int i=0; i<(sizeof(threads)/sizeof(pthread_t)); i++) {
+      for(int i=0; i<thread_amount; i++) {
           //printf("joining %d\n", i);
           pthread_join(threads[i], NULL);
       }

From e0f2e3a3301652803a9d16c6f58a640ad996e868 Mon Sep 17 00:00:00 2001
From: Jaakko Korhonen <jaakko.korhonen@arm.com>
Date: Wed, 12 Jul 2017 13:49:02 +0300
Subject: [PATCH 3/3] Explicit declaration for i and j.

---
 test/Test.cpp | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/test/Test.cpp b/test/Test.cpp
index 25f93c7..9f24efa 100644
--- a/test/Test.cpp
+++ b/test/Test.cpp
@@ -492,15 +492,16 @@ TEST(trace, multithread)
     const int thread_amount = 10;
     pthread_t threads[thread_amount];
     int thread_indexes[thread_amount];
+    int i, j;
 
-    for(int j=0; j<10; j++)
+    for(j=0; j<10; j++)
     {
-      for(int i=0; i<thread_amount; i++) {
+      for(i=0; i<thread_amount; i++) {
           //printf("creating %d\n", i);
           thread_indexes[i] = i;
           pthread_create(&threads[i], NULL, &multithread_printer, (void *)&thread_indexes[i]);
       }
-      for(int i=0; i<thread_amount; i++) {
+      for(i=0; i<thread_amount; i++) {
           //printf("joining %d\n", i);
           pthread_join(threads[i], NULL);
       }