implement Semaphore

engine/os/posix/Semaphore.h

@@ -0,0 +1,105 @@
+/*
+Copyright (c) 2013 Daniele Bartolini, Michele Rossi
+Copyright (c) 2012 Daniele Bartolini, Simone Boscaratto
+
+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 <errno.h>
+#include <semaphore.h>
+#include <time.h>
+#include <pthread.h>
+
+#include "Assert.h"
+#include "Mutex.h"
+#include "Cond.h"
+
+namespace crown
+{
+
+class Semaphore
+{
+public:
+
+	Semaphore();
+	~Semaphore();
+
+	void	post(uint32_t count = 1);
+	void	wait();
+
+private:
+
+	Mutex m_mutex;
+	Cond m_cond;
+	int32_t m_count;
+
+private:
+
+	Semaphore(const Semaphore& s); // no copy constructor
+	Semaphore& operator=(const Semaphore& s); // no assignment operator
+
+};
+
+//-----------------------------------------------------------------------------
+inline Semaphore::Semaphore() : m_count(0)
+{
+}
+
+//-----------------------------------------------------------------------------
+inline Semaphore::~Semaphore()
+{
+}
+
+//-----------------------------------------------------------------------------
+inline void Semaphore::post(uint32_t count)
+{
+	m_mutex.lock();
+
+	for (uint32_t i = 0; i < count; i++)
+	{
+		m_cond.signal();
+	}
+
+	m_count += count;
+
+	m_mutex.unlock();	
+}
+
+//-----------------------------------------------------------------------------
+inline void Semaphore::wait()
+{
+	m_mutex.lock();
+
+	while (m_count <= 0)
+	{
+		m_cond.wait(m_mutex);
+	}
+
+	m_count--;
+
+	m_mutex.unlock();
+}
+
+
+} // namespace crown