Fix typo.

[pintos-anon] / doc / userprog.texi

diff --git a/doc/userprog.texi b/doc/userprog.texi
index 11d9875ce7beabe78e2ebb8e9079d7402bb31113..8524219bf0acc5052f5d75e52817fd4999b2bb79 100644 (file)
--- a/doc/userprog.texi
+++ b/doc/userprog.texi
@@ -301,7 +301,7 @@ regardless of what user process or kernel thread is running.  In
 Pintos, kernel virtual memory is mapped one-to-one to physical
 memory, starting at @code{PHYS_BASE}.  That is, virtual address
 @code{PHYS_BASE} accesses physical
 Pintos, kernel virtual memory is mapped one-to-one to physical
 memory, starting at @code{PHYS_BASE}.  That is, virtual address
 @code{PHYS_BASE} accesses physical

-address 0, virtual address @code{PHYS_BASE} + @t{0x1234} access
+address 0, virtual address @code{PHYS_BASE} + @t{0x1234} accesses

 physical address @t{0x1234}, and so on up to the size of the machine's
 physical memory.
 
 physical address @t{0x1234}, and so on up to the size of the machine's
 physical memory.
 


@@ -619,10 +619,11 @@ the program cannot load or run for any reason.
 @end deftypefn
 
 @deftypefn {System Call} int wait (pid_t @var{pid})
 @end deftypefn
 
 @deftypefn {System Call} int wait (pid_t @var{pid})

-Waits for process @var{pid} to die and returns the status it passed to
-@code{exit}.  Returns -1 if @var{pid}
+If process @var{pid} is still alive, waits until it dies.
+Then, returns the status that @var{pid} passed to @code{exit},
+or -1 if @var{pid}

 was terminated by the kernel (e.g.@: killed due to an exception).  If
 was terminated by the kernel (e.g.@: killed due to an exception).  If

-@var{pid} is does not refer to a child of the
+@var{pid} does not refer to a child of the

 calling thread, or if @code{wait} has already been successfully
 called for the given @var{pid}, returns -1 immediately, without
 waiting.
 calling thread, or if @code{wait} has already been successfully
 called for the given @var{pid}, returns -1 immediately, without
 waiting.


@@ -674,6 +675,12 @@ as explicitly described below.
 
 Each process has an independent set of file descriptors.  File
 descriptors are not inherited by child processes.
 
 Each process has an independent set of file descriptors.  File
 descriptors are not inherited by child processes.

+
+When a single file is opened more than once, whether by a single
+process or different processes, each @code{open} returns a new file
+descriptor.  Different file descriptors for a single file are closed
+independently in separate calls to @code{close} and they do not share
+a file position.

 @end deftypefn
 
 @deftypefn {System Call} int filesize (int @var{fd})
 @end deftypefn
 
 @deftypefn {System Call} int filesize (int @var{fd})