diff -r e57bfdb4f12c -r caafe12b0378 src/core/model/unix-system-condition.cc
--- a/src/core/model/unix-system-condition.cc	Sun Dec 07 22:08:04 2014 -0800
+++ b/src/core/model/unix-system-condition.cc	Tue Dec 09 13:17:49 2014 -0800
@@ -25,28 +25,66 @@
 #include "log.h"
 
 
+/**
+ * \file
+ * \ingroup thread
+ * Thread conditional wait implementation for Unix-like systems.
+ */
+
 namespace ns3 {
 
 NS_LOG_COMPONENT_DEFINE ("SystemCondition");
 
+/**
+ * \ingroup thread
+ * Implementation of SystemCondition for Unix-like systems.
+ */
 class SystemConditionPrivate {
 public:
   /// Conversion from ns to s.
   static const uint64_t NS_PER_SEC = (uint64_t)1000000000;
 
+  /** Constructor. */
   SystemConditionPrivate ();
+  /** Destructor. */
   ~SystemConditionPrivate ();
-	
+
+  /**
+   * Set the condition.
+   *
+   * \param condition The new condition value.
+   */
   void SetCondition (bool condition);
+  /**
+   * Get the condition value.
+   *
+   * \returns The condition value.
+   */
   bool GetCondition (void);
+  /** Signal the condition. */
   void Signal (void);
+  /** Broadcast the condition. */
   void Broadcast (void);
+  /**
+   * Unset the condition, then wait for another thread
+   * to set it with SetCondition. */
   void Wait (void);
+  /**
+   * Unset the condition, then wait for a limited amount of wall-clock
+   * time for another thread to set it with SetCondition.
+   *
+   * \param ns Maximum time to wait, in ns.
+   * \returns \c true if the condition timed out; \c false if the other
+   * thread set it.
+   */
   bool TimedWait (uint64_t ns);
 
 private:
+  /** Mutex controlling access to the condition. */
   pthread_mutex_t m_mutex;
+  /** The pthread condition variable. */
   pthread_cond_t  m_cond;
+  /** The condition state. */
   bool m_condition;
 };