example for logger class + minor improvements

examples/c++/logger.cxx

@@ -1,16 +1,34 @@
+#include <thread>
+#include <vector>
+
 #include "upm_logger.hpp"
 
 using namespace upm;
 
+void print()
+{
+  UPM_LOG(LOG_DEBUG) << "Thread " << std::this_thread::get_id() << ": running loop with 3 iterations";
+
+  for (int i = 0; i < 4; ++i) {
+    UPM_LOG(LOG_DEBUG) << std::this_thread::get_id() << ": i = " << i;
+  }
+}
+
 int main()
 {
+  std::vector<std::thread> threads;
 
   UPM_LOGGER::LogLevel() = LOG_INFO;
 
-  UPM_LOG(LOG_WARNING) << "a loop with 4 iterations";
+  UPM_LOG(LOG_WARNING) << "Testing the upm logger";
 
-  for (int i = 0; i < 4; ++i) {
-    UPM_LOG(LOG_DEBUG) << "i = " << i;
+  // Launching 5 threads
+  for (int i = 0; i < 5; ++i) {
+    threads.push_back(std::thread(print));
+  }
+
+  for (auto& thread : threads) {
+    thread.join();
   }
 
   return 0;

include/upm_logger.hpp

@@ -1,3 +1,27 @@
+/*
+ * Author: Mihai Stefanescu <mihai.stefanescu@rinftech.com>
+ * Copyright (c) 2018 Intel Corporation.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
 #pragma once
 
 #include <sstream>
@@ -38,13 +62,10 @@ namespace upm {
 
   class UPM_LOGGER {
   public:
-    UPM_LOGGER();
+    UPM_LOGGER() {}
     virtual ~UPM_LOGGER();
     std::ostringstream& log(UpmLogLevel level = LOG_ERROR);
     static UpmLogLevel& LogLevel();
-
-    static std::ofstream logStream;
-    static std::mutex logMutex;
   protected:
     std::ostringstream os;
   private:
@@ -53,32 +74,33 @@ namespace upm {
   private:
     // Track logLevel for this particular instance of UPM_LOGGER
     UpmLogLevel logLevel;
-
+    std::ofstream logStream;
+    static std::mutex logMutex;
   public:
-    static const std::string& getLogLevelName(UpmLogLevel level)
-    {
-      if (level < LOG_ERROR || level >= NA) {
-        return NULL;
-      }
-
-      return logLevelNames[level];
-    }
-
-  public:
-    static void write(std::ostringstream& os)
-    {
-
-
-      std::lock_guard<std::mutex> lock(logMutex);
-
-      logStream.open(LOG_FILE, std::ios_base::app);
-      logStream << os.str();
-      logStream.flush();
-    }
+    static const std::string& getLogLevelName(UpmLogLevel level);
+  private:
+    void write(std::ostringstream& os);
   };
 
-  UPM_LOGGER::UPM_LOGGER() {}
+  std::mutex UPM_LOGGER::logMutex;
 
+  void UPM_LOGGER::write(std::ostringstream& os)
+  {
+    std::lock_guard<std::mutex> lock(logMutex);
+
+    logStream.open(LOG_FILE, std::ios_base::app);
+    logStream << os.str();
+    logStream.flush();
+  }
+
+  const std::string& UPM_LOGGER::getLogLevelName(UpmLogLevel level)
+  {
+    if (level < LOG_ERROR || level >= NA) {
+      return NULL;
+    }
+
+    return logLevelNames[level];
+  }
 
   UpmLogLevel& UPM_LOGGER::LogLevel()
   {