small details

Global.h

@@ -1,5 +1,8 @@
 #pragma once
 
+// pre processor symbols
+//#define VERBOSE
+
 const int DEFAULT_POOL_SIZE = 10;
 const int STARTED = 0;
 const int STOPPED = 1;

Makefile

@@ -1,12 +1,15 @@
-OBJPATH=bin/obj
-EXAMPLEPATH=bin/example
+BINPATH=./bin
+OBJPATH=./obj
 
 all:
-	g++ CondVar.cpp -lpthread -c -o $(OBJPATH)/CondVar.o
-	g++ Mutex.cpp -lpthread -c -o $(OBJPATH)/Mutex.o
-	g++ Task.cpp -lpthread -c -o $(OBJPATH)/Task.o
-	g++ ThreadPool.cpp -lpthread -c -o $(OBJPATH)/ThreadPool.o
-	g++ $(OBJPATH)/CondVar.o $(OBJPATH)/Mutex.o $(OBJPATH)/Task.o $(OBJPATH)/ThreadPool.o threadpool_test.cpp -lpthread -o $(EXAMPLEPATH)threadpool_test
+	g++ CondVar.cpp -lpthread -fpic  -c -o $(OBJPATH)/CondVar.o
+	g++ Mutex.cpp -lpthread -fpic -c -o $(OBJPATH)/Mutex.o
+	g++ Task.cpp -lpthread -fpic -c -o $(OBJPATH)/Task.o
+	g++ ThreadPool.cpp -lpthread -fpic -c -o $(OBJPATH)/ThreadPool.o
+	g++ -fPIC -shared -lpthread $(OBJPATH)/CondVar.o $(OBJPATH)/Mutex.o $(OBJPATH)/Task.o $(OBJPATH)/ThreadPool.o -o $(BINPATH)/libthreadpool.so
+#	g++ threadpool_test.cpp -L$(BINPATH) -lthreadpool -lpthread -fpic -o $(BINPATH)/threadpool_test
+
+	g++ $(OBJPATH)/CondVar.o $(OBJPATH)/Mutex.o $(OBJPATH)/Task.o $(OBJPATH)/ThreadPool.o threadpool_test.cpp -lpthread -o $(BINPATH)/threadpool_test
 
 #all:
 #	g++ threadpool.cpp -lpthread -fpic -c -o bin/obj/threadpool.o

Task.cpp

@@ -7,7 +7,8 @@ Task::~Task() {
 }
 
 void Task::operator()() {
-  (*m_fn_ptr)(m_arg);
+  // (*m_fn_ptr)(m_arg);
+  run(); // we can reuse run() here instead of copying the code from run
   if (m_arg != NULL) {
     delete m_arg;
   }

ThreadPool.cpp

@@ -2,12 +2,16 @@
 
 ThreadPool::ThreadPool() : m_pool_size(DEFAULT_POOL_SIZE)
 {
+  #ifdef VERBOSE
   cout << "Constructed ThreadPool of size " << m_pool_size << endl;
+  #endif
 }
 
 ThreadPool::ThreadPool(int pool_size) : m_pool_size(pool_size)
 {
+  #ifdef VERBOSE
   cout << "Constructed ThreadPool of size " << m_pool_size << endl;
+  #endif
 }
 
 ThreadPool::~ThreadPool()
@@ -43,7 +47,9 @@ int ThreadPool::initialize_threadpool()
     }
     m_threads.push_back(tid);
   }
+  #ifdef VERBOSE
   cout << m_pool_size << " threads created by the thread pool" << endl;
+  #endif
 
   return 0;
 }
@@ -57,27 +63,37 @@ int ThreadPool::destroy_threadpool()
   m_task_mutex.lock();
   m_pool_state = STOPPED;
   m_task_mutex.unlock();
+  #ifdef VERBOSE
   cout << "Broadcasting STOP signal to all threads..." << endl;
+  #endif
   m_task_cond_var.broadcast(); // notify all threads we are shttung down
 
   int ret = -1;
   for (int i = 0; i < m_pool_size; i++) {
     void* result;
     ret = pthread_join(m_threads[i], &result);
+    #ifdef VERBOSE
     cout << "pthread_join() returned " << ret << ": " << strerror(errno) << endl;
+    #endif
     m_task_cond_var.broadcast(); // try waking up a bunch of threads that are still waiting
   }
+  #ifdef VERBOSE
   cout << m_pool_size << " threads exited from the thread pool" << endl;
+  #endif
   return 0;
 }
 
 void* ThreadPool::execute_thread()
 {
   Task* task = NULL;
+  #ifdef VERBOSE
   cout << "Starting thread " << pthread_self() << endl;
+  #endif
   while(true) {
     // Try to pick a task
+    #ifdef VERBOSE
     cout << "Locking: " << pthread_self() << endl;
+    #endif
     m_task_mutex.lock();
 
     // We need to put pthread_cond_wait in a loop for two reasons:
@@ -89,27 +105,33 @@ void* ThreadPool::execute_thread()
     while ((m_pool_state != STOPPED) && (m_tasks.empty())) {
       // Wait until there is a task in the queue
       // Unlock mutex while wait, then lock it back when signaled
+      #ifdef VERBOSE
       cout << "Unlocking and waiting: " << pthread_self() << endl;
+      #endif
       m_task_cond_var.wait(m_task_mutex.get_mutex_ptr());
+      #ifdef VERBOSE
       cout << "Signaled and locking: " << pthread_self() << endl;
+      #endif
     }
 
     // If the thread was woken up to notify process shutdown, return from here
     if (m_pool_state == STOPPED) {
+      #ifdef VERBOSE
       cout << "Unlocking and exiting: " << pthread_self() << endl;
+      #endif
       m_task_mutex.unlock();
       pthread_exit(NULL);
     }
 
     task = m_tasks.front();
     m_tasks.pop_front();
+    #ifdef VERBOSE
     cout << "Unlocking: " << pthread_self() << endl;
+    #endif
     m_task_mutex.unlock();
 
-    //cout << "Executing thread " << pthread_self() << endl;
     // execute the task
     (*task)(); // could also do task->run(arg);
-    //cout << "Done executing thread " << pthread_self() << endl;
     delete task;
   }
   return NULL;

threadpool_test.cpp

@@ -12,7 +12,6 @@ void hello(void* arg)
 {
   int* x = (int*) arg;
   cout << "Hello " << *x << endl;
-//  cout << "\n";
 }
 
 int main(int argc, char* argv[])