Initial checkin of unified hierarchy of WPILib 2015

hal/Athena/src/main/native/cpp/Synchronized.cpp

@@ -0,0 +1,49 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) FIRST 2008. All Rights Reserved.							  */
+/* Open Source Software - may be modified and shared by FRC teams. The code   */
+/* must be accompanied by the FIRST BSD license file in $(WIND_BASE)/WPILib.  */
+/*----------------------------------------------------------------------------*/
+
+#include "HAL/cpp/Synchronized.h"
+#include "HAL/Semaphore.h"
+
+/**
+ * Synchronized class deals with critical regions.
+ * Declare a Synchronized object at the beginning of a block. That will take the semaphore.
+ * When the code exits from the block it will call the destructor which will give the semaphore.
+ * This ensures that no matter how the block is exited, the semaphore will always be released.
+ * Use the CRITICAL_REGION(SEM_ID) and END_REGION macros to make the code look cleaner (see header file)
+ * @param semaphore The semaphore controlling this critical region.
+ */
+Synchronized::Synchronized(MUTEX_ID semaphore)
+{
+	m_mutex = semaphore;
+	m_semaphore = NULL;
+	takeMutex(m_mutex, SEMAPHORE_WAIT_FOREVER);
+}
+
+Synchronized::Synchronized(SEMAPHORE_ID semaphore)
+{
+	m_mutex = NULL;
+	m_semaphore = semaphore;
+	takeSemaphore(m_semaphore, SEMAPHORE_WAIT_FOREVER);
+}
+
+Synchronized::Synchronized(ReentrantSemaphore& semaphore)
+{
+	m_mutex = semaphore.m_semaphore;
+	m_semaphore = NULL;
+	takeMutex(m_mutex, SEMAPHORE_WAIT_FOREVER);
+}
+
+/**
+ * This destructor unlocks the semaphore.
+ */
+Synchronized::~Synchronized()
+{
+	if (m_mutex != NULL) {
+		giveMutex(m_mutex);
+	} else {
+		giveSemaphore(m_semaphore);
+	}
+}