X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=doc%2Fthreads.texi;h=2f42e3dc5979b8f8ab33fd79db7af020a285c932;hb=01b1921d261ad0dffb13726e3c354a1b74ca2afd;hp=58cf31609fd1d956e2c70285db3d4bfa1c1e8adf;hpb=615bf3b3d2a8573ed6fb9ddc0055745e163ac999;p=pintos-anon

diff --git a/doc/threads.texi b/doc/threads.texi
index 58cf316..2f42e3d 100644
--- a/doc/threads.texi
+++ b/doc/threads.texi
@@ -461,10 +461,9 @@ a lock that @var{M} holds and @var{M} is waiting on a lock that @var{L}
 holds, then both @var{M} and @var{L} should be boosted to @var{H}'s
 priority.
 
-You need not implement priority donation when a thread is waiting
-for a lock held by a lower-priority thread.  You need not
-implement priority donation for semaphores or condition variables,
-but you are welcome to do so.  You do need to implement
+You must implement priority donation for locks.  You need not
+implement priority donation for semaphores or condition variables
+(but you are welcome to do so).  You do need to implement
 priority scheduling in all cases.
 
 Finally, implement the following functions that allow a thread to
@@ -481,6 +480,9 @@ Returns the current thread's priority.  In the presence of priority
 donation, returns the higher (donated) priority.
 @end deftypefun
 
+You need not provide any interface to allow a thread to directly modify
+other threads' priorities.
+
 The priority scheduler is not used in any later project.
 
 @node Advanced Scheduler
@@ -627,7 +629,7 @@ list.
 Yes.  As long as there is a single highest-priority thread, it continues
 running until it blocks or finishes, even if it calls
 @func{thread_yield}.
-If there are multiple threads have the same highest priority,
+If multiple threads have the same highest priority,
 @func{thread_yield} should switch among them in ``round robin'' order.
 
 @item What happens to the priority of a donating thread?
@@ -653,6 +655,12 @@ processor.  It is not acceptable to wait for the next timer interrupt.
 The highest priority thread should run as soon as it is runnable,
 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.
+
 @item Calling @func{printf} in @func{sema_up} or @func{sema_down} reboots!
 
 @anchor{printf Reboots}