rtc: Fix Unix epoch conversion from RTC time.

[pintos-anon] / doc / userprog.tmpl

diff --git a/doc/userprog.tmpl b/doc/userprog.tmpl
index a8b4269e9c5c1de6025b289a91afd490c3ea3cbd..03c7fa015c563f2b24849803e433a942719759e1 100644 (file)
--- a/doc/userprog.tmpl
+++ b/doc/userprog.tmpl
@@ -1,8 +1,8 @@
-                    +--------------------------+
-                            |          CS 140          |
-                    | PROJECT 2: USER PROGRAMS |
-                    |     DESIGN DOCUMENT      |
-                    +--------------------------+
+             +--------------------------+
+             |          CS 140          |
+             | PROJECT 2: USER PROGRAMS |
+             |     DESIGN DOCUMENT      |
+             +--------------------------+

 
 ---- GROUP ----
 
 
 ---- GROUP ----
 


@@ -19,97 +19,100 @@ FirstName LastName <email@domain.example>
 
 >> Please cite any offline or online sources you consulted while
 >> preparing your submission, other than the Pintos documentation, course
 
 >> Please cite any offline or online sources you consulted while
 >> preparing your submission, other than the Pintos documentation, course

->> text, and lecture notes.
+>> text, lecture notes, and course staff.

 
 

-                          ARGUMENT PASSING
-                          ================
+               ARGUMENT PASSING
+               ================

 
 ---- DATA STRUCTURES ----
 
 
 ---- DATA STRUCTURES ----
 

->> Copy here the declaration of each new or changed `struct' or `struct'
->> member, global or static variable, `typedef', or enumeration.
->> Identify the purpose of each in 25 words or less.
+>> A1: Copy here the declaration of each new or changed `struct' or
+>> `struct' member, global or static variable, `typedef', or
+>> enumeration.  Identify the purpose of each in 25 words or less.

 
 ---- ALGORITHMS ----
 
 
 ---- ALGORITHMS ----
 

->> Briefly describe how you implemented argument parsing.  How do you
->> arrange for the elements of argv[] to be in the right order?  How do
->> you avoid overflowing the stack page?
+>> A2: Briefly describe how you implemented argument parsing.  How do
+>> you arrange for the elements of argv[] to be in the right order?
+>> How do you avoid overflowing the stack page?

 
 ---- RATIONALE ----
 
 
 ---- RATIONALE ----
 

->> Why does Pintos implement strtok_r() but not strtok()?
+>> A3: Why does Pintos implement strtok_r() but not strtok()?

 
 

->> In Pintos, the kernel separates commands into a executable name and
->> arguments.  In Unix-like systems, the shell does this separation.
->> Identify at least two advantages of the Unix approach.
+>> A4: In Pintos, the kernel separates commands into a executable name
+>> and arguments.  In Unix-like systems, the shell does this
+>> separation.  Identify at least two advantages of the Unix approach.

 
 

-                            SYSTEM CALLS
-                            ============
+                 SYSTEM CALLS
+                 ============

 
 ---- DATA STRUCTURES ----
 
 
 ---- DATA STRUCTURES ----
 

->> Copy here the declaration of each new or changed `struct' or `struct'
->> member, global or static variable, `typedef', or enumeration.
->> Identify the purpose of each in 25 words or less.
+>> B1: Copy here the declaration of each new or changed `struct' or
+>> `struct' member, global or static variable, `typedef', or
+>> enumeration.  Identify the purpose of each in 25 words or less.

 
 

->> Describe how file descriptors are associated with open files.  Are
->> file descriptors unique within the entire OS or just within a single
->> process?
+>> B2: Describe how file descriptors are associated with open files.
+>> Are file descriptors unique within the entire OS or just within a
+>> single process?

 
 ---- ALGORITHMS ----
 
 
 ---- ALGORITHMS ----
 

->> Describe your code for reading and writing user data from the kernel.
-
->> Suppose a system call causes a full page (4,096 bytes) of data to be
->> copied from user space into the kernel.  What is the least and the
->> greatest possible number of inspections of the page table (e.g. calls
->> to pagedir_get_page()) that might result?  What about for a system
->> call that only copies 2 bytes of data?  Is there room for improvement
->> in these numbers, and how much?
-
->> Briefly describe your implementation of the "wait" system call and how
->> it interacts with process termination.
-
->> Any access to user program memory at a user-specified address can fail
->> due to a bad pointer value.  Such accesses must cause the process to
->> be terminated.  System calls are fraught with such accesses, e.g. a
->> "write" system call requires reading the system call number from the
->> user stack, then each of the call's three arguments, then an arbitrary
->> amount of user memory, and any of these can fail at any point.  This
->> poses a design and error-handling problem: how do you best avoid
->> obscuring the primary function of code in a morass of error-handling?
->> Furthermore, when an error is detected, how do you ensure that all
->> temporarily allocated resources (locks, buffers, etc.) are freed?  In
->> a few paragraphs, describe the strategy or strategies you adopted for
+>> B3: Describe your code for reading and writing user data from the
+>> kernel.
+
+>> B4: Suppose a system call causes a full page (4,096 bytes) of data
+>> to be copied from user space into the kernel.  What is the least
+>> and the greatest possible number of inspections of the page table
+>> (e.g. calls to pagedir_get_page()) that might result?  What about
+>> for a system call that only copies 2 bytes of data?  Is there room
+>> for improvement in these numbers, and how much?
+
+>> B5: Briefly describe your implementation of the "wait" system call
+>> and how it interacts with process termination.
+
+>> B6: Any access to user program memory at a user-specified address
+>> can fail due to a bad pointer value.  Such accesses must cause the
+>> process to be terminated.  System calls are fraught with such
+>> accesses, e.g. a "write" system call requires reading the system
+>> call number from the user stack, then each of the call's three
+>> arguments, then an arbitrary amount of user memory, and any of
+>> these can fail at any point.  This poses a design and
+>> error-handling problem: how do you best avoid obscuring the primary
+>> function of code in a morass of error-handling?  Furthermore, when
+>> an error is detected, how do you ensure that all temporarily
+>> allocated resources (locks, buffers, etc.) are freed?  In a few
+>> paragraphs, describe the strategy or strategies you adopted for

 >> managing these issues.  Give an example.
 
 ---- SYNCHRONIZATION ----
 
 >> managing these issues.  Give an example.
 
 ---- SYNCHRONIZATION ----
 

->> The "exec" system call returns -1 if loading the new executable fails,
->> so it cannot return before the new executable has completed loading.
->> How does your code ensure this?  How is the load success/failure
->> status passed back to the thread that calls "exec"?
+>> B7: The "exec" system call returns -1 if loading the new executable
+>> fails, so it cannot return before the new executable has completed
+>> loading.  How does your code ensure this?  How is the load
+>> success/failure status passed back to the thread that calls "exec"?

 
 

->> Consider parent process P with child process C.  How do you ensure
->> proper synchronization and avoid race conditions when P calls wait(C)
->> before C exits?  After C exits?  How do you ensure that all resources
->> are freed in each case?  How about when P terminates without waiting,
->> before C exits?  After C exits?  Are there any special cases?
+>> B8: Consider parent process P with child process C.  How do you
+>> ensure proper synchronization and avoid race conditions when P
+>> calls wait(C) before C exits?  After C exits?  How do you ensure
+>> that all resources are freed in each case?  How about when P
+>> terminates without waiting, before C exits?  After C exits?  Are
+>> there any special cases?

 
 ---- RATIONALE ----
 
 
 ---- RATIONALE ----
 

->> Why did you choose to implement access to user memory from the
+>> B9: Why did you choose to implement access to user memory from the

 >> kernel in the way that you did?
 
 >> kernel in the way that you did?
 

->> What advantages or disadvantages can you see to your design for file
->> descriptors?
+>> B10: What advantages or disadvantages can you see to your design
+>> for file descriptors?

 
 

->> The default tid_t to pid_t mapping is the identity mapping.  If you
->> changed it, what advantages are there to your approach?
+>> B11: The default tid_t to pid_t mapping is the identity mapping.
+>> If you changed it, what advantages are there to your approach?

 
 

-                          SURVEY QUESTIONS
-                          ================
+               SURVEY QUESTIONS
+               ================

 
 Answering these questions is optional, but it will help us improve the
 course in future quarters.  Feel free to tell us anything you
 
 Answering these questions is optional, but it will help us improve the
 course in future quarters.  Feel free to tell us anything you