Index: include/synch/synch.h
===================================================================
--- include/synch/synch.h	(revision 9cefba4b1f94a13c79f6ebc767ee59e56a86cbf8)
+++ include/synch/synch.h	(revision ba1b2194cc406f4d64bc3c4f97a11c045ca42d60)
@@ -30,5 +30,5 @@
 #define __SYNCH_H__
 
-#define SYNCH_NO_TIMEOUT	0	/**< No timeout is request. */
+#define SYNCH_NO_TIMEOUT	0	/**< Request with no timeout. */
 #define SYNCH_BLOCKING		0	/**< Blocking operation request. */
 #define SYNCH_NON_BLOCKING	1	/**< Non-blocking operation request. */
Index: include/time/timeout.h
===================================================================
--- include/time/timeout.h	(revision 9cefba4b1f94a13c79f6ebc767ee59e56a86cbf8)
+++ include/time/timeout.h	(revision ba1b2194cc406f4d64bc3c4f97a11c045ca42d60)
@@ -37,17 +37,17 @@
 #define us2ticks(us)	((__u64)(((__u32) (us)/(1000000/HZ))))
 
-typedef void (* timeout_handler)(void *arg);
+typedef void (* timeout_handler_t)(void *arg);
 
 struct timeout {
 	spinlock_t lock;
 
-	link_t link;
+	link_t link;			/**< Link to the list of active timeouts on THE->cpu */
 	
-	__u64 ticks;
+	__u64 ticks;			/**< Timeout will be activated in this amount of clock() ticks. */
 
-	timeout_handler handler;
-	void *arg;
+	timeout_handler_t handler;	/**< Function that will be called on timeout activation. */
+	void *arg;			/**< Argument to be passed to handler() function. */
 	
-	cpu_t *cpu;
+	cpu_t *cpu;			/**< On which processor is this timeout registered. */
 };
 
@@ -55,6 +55,6 @@
 extern void timeout_initialize(timeout_t *t);
 extern void timeout_reinitialize(timeout_t *t);
-extern void timeout_register(timeout_t *t, __u64 usec, timeout_handler f, void *arg);
-extern int timeout_unregister(timeout_t *t);
+extern void timeout_register(timeout_t *t, __u64 usec, timeout_handler_t f, void *arg);
+extern bool timeout_unregister(timeout_t *t);
 
 #endif
Index: src/preempt/preemption.c
===================================================================
--- src/preempt/preemption.c	(revision 9cefba4b1f94a13c79f6ebc767ee59e56a86cbf8)
+++ src/preempt/preemption.c	(revision ba1b2194cc406f4d64bc3c4f97a11c045ca42d60)
@@ -33,4 +33,5 @@
 #include <debug.h>
 
+/** Increment preemption disabled counter. */
 void preemption_disable(void)
 {
@@ -39,4 +40,5 @@
 }
 
+/** Decrement preemption disabled counter. */
 void preemption_enable(void)
 {
Index: src/time/clock.c
===================================================================
--- src/time/clock.c	(revision 9cefba4b1f94a13c79f6ebc767ee59e56a86cbf8)
+++ src/time/clock.c	(revision ba1b2194cc406f4d64bc3c4f97a11c045ca42d60)
@@ -53,5 +53,5 @@
 	link_t *l;
 	timeout_t *h;
-	timeout_handler f;
+	timeout_handler_t f;
 	void *arg;
 
Index: src/time/timeout.c
===================================================================
--- src/time/timeout.c	(revision 9cefba4b1f94a13c79f6ebc767ee59e56a86cbf8)
+++ src/time/timeout.c	(revision ba1b2194cc406f4d64bc3c4f97a11c045ca42d60)
@@ -53,9 +53,9 @@
 
 
-/** Initialize empty timeout list
- *
- * Initialize the timeout list to be empty.
- *
- * @param t Timeout list to be initialized.
+/** Reinitialize timeout 
+ *
+ * Initialize all members except the lock.
+ *
+ * @param t Timeout to be initialized.
  *
  */
@@ -70,9 +70,9 @@
 
 
-/** Initialize timeout list
- *
- * Initialize the timeout list and its spinlock.
- *
- * @param t Timeout list to be initialized.
+/** Initialize timeout
+ *
+ * Initialize all members including the lock.
+ *
+ * @param t Timeout to be initialized.
  *
  */
@@ -84,11 +84,11 @@
 
 
-/** Register timeout callback
- *
- * Insert the timeout handler f (with argument arg)
- * to the timeout list and make it execute in
+/** Register timeout
+ *
+ * Insert timeout handler f (with argument arg)
+ * to timeout list and make it execute in
  * time microseconds (or slightly more).
  *
- * @param t    Timeout list.
+ * @param t    Timeout structure.
  * @param time Number of usec in the future to execute
  *             the handler.
@@ -97,5 +97,5 @@
  *
  */
-void timeout_register(timeout_t *t, __u64 time, timeout_handler f, void *arg)
+void timeout_register(timeout_t *t, __u64 time, timeout_handler_t f, void *arg)
 {
 	timeout_t *hlp;
@@ -157,5 +157,5 @@
 
 
-/** Unregister timeout callback
+/** Unregister timeout
  *
  * Remove timeout from timeout list.
@@ -163,6 +163,7 @@
  * @param t Timeout to unregister.
  *
- */
-int timeout_unregister(timeout_t *t)
+ * @return true on success, false on failure.
+ */
+bool timeout_unregister(timeout_t *t)
 {
 	timeout_t *hlp;
@@ -176,5 +177,5 @@
 		spinlock_unlock(&t->lock);
 		cpu_priority_restore(pri);
-		return 0;
+		return false;
 	}
 	if (!spinlock_trylock(&t->cpu->timeoutlock)) {
@@ -204,4 +205,4 @@
 
 	cpu_priority_restore(pri);
-	return 1;
-}
+	return true;
+}