4 files changed, 12 insertions, 7 deletions
diff --git a/src/thread/thread.h b/src/thread/thread.h
index 98c48d15d..83eeb73eb 100644
--- a/src/thread/thread.h
+++ b/src/thread/thread.h
@@ -12,8 +12,10 @@
 #ifndef THREAD_H
 #define THREAD_H
 
+/** Definition of all thread entry functions. */
 typedef void (*OTTDThreadFunc)(void *);
 
+/** Signal used for signalling we knowingly want to end the thread. */
 class OTTDThreadExitSignal { };
 
 /**
@@ -52,6 +54,9 @@ public:
  */
 class ThreadMutex {
 public:
+	/**
+	 * Create a new mutex.
+	 */
 	static ThreadMutex *New();
 
 	/**
diff --git a/src/thread/thread_os2.cpp b/src/thread/thread_os2.cpp
index c6c7db7df..903ea0ebe 100644
--- a/src/thread/thread_os2.cpp
+++ b/src/thread/thread_os2.cpp
@@ -93,8 +93,8 @@ private:
  */
 class ThreadMutex_OS2 : public ThreadMutex {
 private:
-	HMTX mutex;
-	HEV event;
+	HMTX mutex; ///< The mutex.
+	HEV event;  ///< Event for waiting.
 
 public:
 	ThreadMutex_OS2()
diff --git a/src/thread/thread_pthread.cpp b/src/thread/thread_pthread.cpp
index ab46c0a0a..11cd3accd 100644
--- a/src/thread/thread_pthread.cpp
+++ b/src/thread/thread_pthread.cpp
@@ -95,9 +95,9 @@ private:
  */
 class ThreadMutex_pthread : public ThreadMutex {
 private:
-	pthread_mutex_t mutex;
-	pthread_cond_t condition;
-	pthread_mutexattr_t attr;
+	pthread_mutex_t mutex;    ///< The actual mutex.
+	pthread_cond_t condition; ///< Data for conditional waiting.
+	pthread_mutexattr_t attr; ///< Attributes set for the mutex.
 
 public:
 	ThreadMutex_pthread()
diff --git a/src/thread/thread_win32.cpp b/src/thread/thread_win32.cpp
index a3b2d3734..1e7d0731e 100644
--- a/src/thread/thread_win32.cpp
+++ b/src/thread/thread_win32.cpp
@@ -106,8 +106,8 @@ private:
  */
 class ThreadMutex_Win32 : public ThreadMutex {
 private:
-	CRITICAL_SECTION critical_section;
-	HANDLE event;
+	CRITICAL_SECTION critical_section; ///< The critical section we would enter.
+	HANDLE event;                      ///< Event for signalling.
 
 public:
 	ThreadMutex_Win32()