Clarify ROX.

[pintos-anon] / doc / userprog.texi

diff --git a/doc/userprog.texi b/doc/userprog.texi
index d401fda025f1f98b81ed78a31c743ccbd30bf68e..71b084ac3b02106877626dcbea6165112f193a3b 100644 (file)
--- a/doc/userprog.texi
+++ b/doc/userprog.texi
@@ -683,7 +683,8 @@ actual number written, or -1 if no bytes could be written at all.
 
 Fd 1 writes to the console.  Your code to write to the console should
 write all of @var{buffer} in one call to @func{putbuf}, at least as
 
 Fd 1 writes to the console.  Your code to write to the console should
 write all of @var{buffer} in one call to @func{putbuf}, at least as

-long as @var{size} is not bigger than a few hundred bytes.  Otherwise,
+long as @var{size} is not bigger than a few hundred bytes.  (It is
+reasonable to break up larger buffers.)  Otherwise,

 lines of text output by different processes may end up interleaved on
 the console, confusing both human readers and our grading scripts.
 
 lines of text output by different processes may end up interleaved on
 the console, confusing both human readers and our grading scripts.
 


@@ -777,7 +778,8 @@ hurt even now.
 You can use @func{file_deny_write} to prevent writes to an open file.
 Calling @func{file_allow_write} on the file will re-enable them (unless
 the file is denied writes by another opener).  Closing a file will also
 You can use @func{file_deny_write} to prevent writes to an open file.
 Calling @func{file_allow_write} on the file will re-enable them (unless
 the file is denied writes by another opener).  Closing a file will also

-re-enable writes.
+re-enable writes.  Thus, to deny writes to process's executable, you
+must keep it open as long as the process is still running.

 
 @node Project 2 FAQ
 @section FAQ
 
 @node Project 2 FAQ
 @section FAQ