X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=doc%2Fthreads.texi;h=eeb17eeac26298c6728c1349abbb5bc3a12f1222;hb=5440a348242d2a56cee111000b676ac3d7d84ea5;hp=51b52f7abb95b80966d3dc684ecfeafaeed5ca5b;hpb=7e97928e155c19be56010f3f8ec2dc8f03c6985c;p=pintos-anon

diff --git a/doc/threads.texi b/doc/threads.texi
index 51b52f7..eeb17ee 100644
--- a/doc/threads.texi
+++ b/doc/threads.texi
@@ -697,6 +697,13 @@ priority to @var{L}.  @var{L} releases the lock and
 thus loses the CPU and is moved to the ready queue.  Now @var{L}'s
 old priority is restored while it is in the ready queue.
 
+@item Can a thread's priority change while it is blocked?
+
+Yes.  While a thread that has acquired lock @var{L} is blocked for any
+reason, its priority can increase by priority donation if a
+higher-priority thread attempts to acquire @var{L}.  This case is
+checked by the @code{priority-donate-sema} test.
+
 @item Can a thread added to the ready list preempt the processor?
 
 Yes.  If a thread added to the ready list has higher priority than the
@@ -707,9 +714,11 @@ preempting whatever thread is currently running.
 
 @item How does @func{thread_set_priority} affect a thread receiving donations?
 
-It should do something sensible, but no particular behavior is
-required.  None of the test cases call @func{thread_set_priority} from a
-thread while it is receiving a priority donation.
+It sets the thread's base priority.  The thread's effective priority
+becomes the higher of the newly set priority or the highest donated
+priority.  When the donations are released, the thread's priority
+becomes the one set through the function call.  This behavior is checked
+by the @code{priority-donate-lower} test.
 
 @item Calling @func{printf} in @func{sema_up} or @func{sema_down} reboots!