2 files changed, 187 insertions, 0 deletions
diff --git a/src/pal/tests/palsuite/miscellaneous/InterlockedCompareExchange/test2/CMakeLists.txt b/src/pal/tests/palsuite/miscellaneous/InterlockedCompareExchange/test2/CMakeLists.txt
new file mode 100644
index 0000000000..038d375273
--- /dev/null
+++ b/src/pal/tests/palsuite/miscellaneous/InterlockedCompareExchange/test2/CMakeLists.txt
@@ -0,0 +1,19 @@
+cmake_minimum_required(VERSION 2.8.12.2)
+
+set(CMAKE_INCLUDE_CURRENT_DIR ON)
+
+set(SOURCES
+  test.cpp
+)
+
+add_executable(paltest_interlockedcompareexchange_test2
+  ${SOURCES}
+)
+
+add_dependencies(paltest_interlockedcompareexchange_test2 coreclrpal)
+
+target_link_libraries(paltest_interlockedcompareexchange_test2
+  pthread
+  m
+  coreclrpal
+)
diff --git a/src/pal/tests/palsuite/miscellaneous/InterlockedCompareExchange/test2/test.cpp b/src/pal/tests/palsuite/miscellaneous/InterlockedCompareExchange/test2/test.cpp
new file mode 100644
index 0000000000..902f626d47
--- /dev/null
+++ b/src/pal/tests/palsuite/miscellaneous/InterlockedCompareExchange/test2/test.cpp
@@ -0,0 +1,168 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+/*============================================================
+**
+** Source : test.c
+**
+** Purpose: Test for InterlockedCompareExchange() function using multiple threads
+**
+**
+**=========================================================*/
+
+
+
+#include <palsuite.h>
+
+#define MAX_THREADS 10
+#define REPEAT_COUNT 10
+
+//Global Variable Declaration
+LONG g_Total = 0;
+LONG Lock=0;
+
+
+void ModifyGlobalResource(void);
+void AcquireLock(PLONG pLock);
+void ReleaseLock(PLONG pLock);
+
+
+
+//Main entry point of the program
+int __cdecl main(int argc, char *argv[]) {
+  
+    int i = 0;
+    DWORD dwThreadID=0;
+    LONG totalOperations = 0;
+
+    HANDLE hThread[MAX_THREADS];
+
+    /*
+     * Initialize the PAL and return FAILURE if this fails
+     */
+
+    if(0 != (PAL_Initialize(argc, argv)))
+    {
+        return FAIL;
+    }
+
+
+	totalOperations = MAX_THREADS * REPEAT_COUNT;
+
+
+	//Create MAX_THREADS threads that will operate on the global counter
+	for (i=0;i<MAX_THREADS;i++)
+	{
+			hThread[i] = CreateThread( 
+				NULL,                        // default security attributes 
+				0,                           // use default stack size  
+				(LPTHREAD_START_ROUTINE) ModifyGlobalResource,    // thread function 
+				NULL,                // argument to thread function 
+				0,                           // use default creation flags 
+				&dwThreadID);                // returns the thread identifier 
+ 
+		   // Check the return value for success. 
+ 
+			if (hThread[i] == NULL) 
+			{
+				Fail("ERROR: Was not able to create thread\n"
+           				 "GetLastError returned %d\n", GetLastError());
+			}
+
+	}
+
+
+	//Wait for all threads to finish
+	for (i=0;i<MAX_THREADS;i++)
+	{
+
+		 if (WAIT_OBJECT_0 != WaitForSingleObject (hThread[i], INFINITE))
+ 		{
+	 		Fail ("Main: Wait for Single Object failed.  Failing test.\n"
+		       "GetLastError returned %d\n", GetLastError());  
+ 		}
+	
+	}
+	
+
+	if (0!= g_Total)
+		{
+			Fail("Test Failed \n");
+		}
+
+	Trace("Global Counter Value at the end of the test %d \n", g_Total);
+
+    /*
+     * Terminate PAL 
+     */
+	
+    PAL_Terminate();
+    return PASS; 
+} 
+
+
+void ModifyGlobalResource(void)
+{
+
+	int i =0;
+	
+	for (i=0;i<REPEAT_COUNT;i++)
+		{
+
+			/*
+				Acquire Lock Provides Synchronization Around g_Total global variable
+			*/
+
+			AcquireLock(&Lock);
+			
+			/*
+			The following set of operations is gauranteed to be atomic by virtue of the fact 
+			that InterLockedCompareExchange was able to gaurantee that the compare 
+			and exchange operation on pLock was thread safe.  If the same set of code was 
+			executed without using InterlockedCompareExchange the code would fail most of 
+			time.
+			
+			*/
+			g_Total++;
+			Sleep(100);
+			g_Total--;
+			if (0!=g_Total)
+				{
+					Fail("Test Failed beacuse g_Total was not protected \n");
+				}
+
+			
+			/*
+				Acquire Lock releases the lock around g_Total Global variable 
+			*/
+
+			ReleaseLock(&Lock);
+		}
+	
+	
+}
+
+
+void AcquireLock(PLONG pLock)
+{
+	//Spin Lock implemented with the help of InterlockedCompareExchange
+
+	
+	while(1)
+		{
+		if (InterlockedCompareExchange(pLock,1,0)==0)
+			break;
+		}
+		
+}
+
+
+void ReleaseLock(PLONG pLock)
+{
+	
+
+	MemoryBarrier();
+	*pLock = 0;
+}
+