update lab1-8 codes and docs. now version is 0.2

LICENSE

@@ -1,388 +1,388 @@
-		    GNU GENERAL PUBLIC LICENSE
-		       Version 2, June 1991
-
- Copyright (C) 1989, 1991 Free Software Foundation, Inc.
-                       59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
- Everyone is permitted to copy and distribute verbatim copies
- of this license document, but changing it is not allowed.
-
-			    Preamble
-
-  The licenses for most software are designed to take away your
-freedom to share and change it.  By contrast, the GNU General Public
-License is intended to guarantee your freedom to share and change free
-software--to make sure the software is free for all its users.  This
-General Public License applies to most of the Free Software
-Foundation's software and to any other program whose authors commit to
-using it.  (Some other Free Software Foundation software is covered by
-the GNU Library General Public License instead.)  You can apply it to
-your programs, too.
-
-  When we speak of free software, we are referring to freedom, not
-price.  Our General Public Licenses are designed to make sure that you
-have the freedom to distribute copies of free software (and charge for
-this service if you wish), that you receive source code or can get it
-if you want it, that you can change the software or use pieces of it
-in new free programs; and that you know you can do these things.
-
-  To protect your rights, we need to make restrictions that forbid
-anyone to deny you these rights or to ask you to surrender the rights.
-These restrictions translate to certain responsibilities for you if you
-distribute copies of the software, or if you modify it.
-
-  For example, if you distribute copies of such a program, whether
-gratis or for a fee, you must give the recipients all the rights that
-you have.  You must make sure that they, too, receive or can get the
-source code.  And you must show them these terms so they know their
-rights.
-
-  We protect your rights with two steps: (1) copyright the software, and
-(2) offer you this license which gives you legal permission to copy,
-distribute and/or modify the software.
-
-  Also, for each author's protection and ours, we want to make certain
-that everyone understands that there is no warranty for this free
-software.  If the software is modified by someone else and passed on, we
-want its recipients to know that what they have is not the original, so
-that any problems introduced by others will not reflect on the original
-authors' reputations.
-
-  Finally, any free program is threatened constantly by software
-patents.  We wish to avoid the danger that redistributors of a free
-program will individually obtain patent licenses, in effect making the
-program proprietary.  To prevent this, we have made it clear that any
-patent must be licensed for everyone's free use or not licensed at all.
-
-  The precise terms and conditions for copying, distribution and
-modification follow.
-
-		    GNU GENERAL PUBLIC LICENSE
-   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
-
-  0. This License applies to any program or other work which contains
-a notice placed by the copyright holder saying it may be distributed
-under the terms of this General Public License.  The "Program", below,
-refers to any such program or work, and a "work based on the Program"
-means either the Program or any derivative work under copyright law:
-that is to say, a work containing the Program or a portion of it,
-either verbatim or with modifications and/or translated into another
-language.  (Hereinafter, translation is included without limitation in
-the term "modification".)  Each licensee is addressed as "you".
-
-Activities other than copying, distribution and modification are not
-covered by this License; they are outside its scope.  The act of
-running the Program is not restricted, and the output from the Program
-is covered only if its contents constitute a work based on the
-Program (independent of having been made by running the Program).
-Whether that is true depends on what the Program does.
-
-  1. You may copy and distribute verbatim copies of the Program's
-source code as you receive it, in any medium, provided that you
-conspicuously and appropriately publish on each copy an appropriate
-copyright notice and disclaimer of warranty; keep intact all the
-notices that refer to this License and to the absence of any warranty;
-and give any other recipients of the Program a copy of this License
-along with the Program.
-
-You may charge a fee for the physical act of transferring a copy, and
-you may at your option offer warranty protection in exchange for a fee.
-
-  2. You may modify your copy or copies of the Program or any portion
-of it, thus forming a work based on the Program, and copy and
-distribute such modifications or work under the terms of Section 1
-above, provided that you also meet all of these conditions:
-
-    a) You must cause the modified files to carry prominent notices
-    stating that you changed the files and the date of any change.
-
-    b) You must cause any work that you distribute or publish, that in
-    whole or in part contains or is derived from the Program or any
-    part thereof, to be licensed as a whole at no charge to all third
-    parties under the terms of this License.
-
-    c) If the modified program normally reads commands interactively
-    when run, you must cause it, when started running for such
-    interactive use in the most ordinary way, to print or display an
-    announcement including an appropriate copyright notice and a
-    notice that there is no warranty (or else, saying that you provide
-    a warranty) and that users may redistribute the program under
-    these conditions, and telling the user how to view a copy of this
-    License.  (Exception: if the Program itself is interactive but
-    does not normally print such an announcement, your work based on
-    the Program is not required to print an announcement.)
-
-These requirements apply to the modified work as a whole.  If
-identifiable sections of that work are not derived from the Program,
-and can be reasonably considered independent and separate works in
-themselves, then this License, and its terms, do not apply to those
-sections when you distribute them as separate works.  But when you
-distribute the same sections as part of a whole which is a work based
-on the Program, the distribution of the whole must be on the terms of
-this License, whose permissions for other licensees extend to the
-entire whole, and thus to each and every part regardless of who wrote it.
-
-Thus, it is not the intent of this section to claim rights or contest
-your rights to work written entirely by you; rather, the intent is to
-exercise the right to control the distribution of derivative or
-collective works based on the Program.
-
-In addition, mere aggregation of another work not based on the Program
-with the Program (or with a work based on the Program) on a volume of
-a storage or distribution medium does not bring the other work under
-the scope of this License.
-
-  3. You may copy and distribute the Program (or a work based on it,
-under Section 2) in object code or executable form under the terms of
-Sections 1 and 2 above provided that you also do one of the following:
-
-    a) Accompany it with the complete corresponding machine-readable
-    source code, which must be distributed under the terms of Sections
-    1 and 2 above on a medium customarily used for software interchange; or,
-
-    b) Accompany it with a written offer, valid for at least three
-    years, to give any third party, for a charge no more than your
-    cost of physically performing source distribution, a complete
-    machine-readable copy of the corresponding source code, to be
-    distributed under the terms of Sections 1 and 2 above on a medium
-    customarily used for software interchange; or,
-
-    c) Accompany it with the information you received as to the offer
-    to distribute corresponding source code.  (This alternative is
-    allowed only for noncommercial distribution and only if you
-    received the program in object code or executable form with such
-    an offer, in accord with Subsection b above.)
-
-The source code for a work means the preferred form of the work for
-making modifications to it.  For an executable work, complete source
-code means all the source code for all modules it contains, plus any
-associated interface definition files, plus the scripts used to
-control compilation and installation of the executable.  However, as a
-special exception, the source code distributed need not include
-anything that is normally distributed (in either source or binary
-form) with the major components (compiler, kernel, and so on) of the
-operating system on which the executable runs, unless that component
-itself accompanies the executable.
-
-If distribution of executable or object code is made by offering
-access to copy from a designated place, then offering equivalent
-access to copy the source code from the same place counts as
-distribution of the source code, even though third parties are not
-compelled to copy the source along with the object code.
-
-  4. You may not copy, modify, sublicense, or distribute the Program
-except as expressly provided under this License.  Any attempt
-otherwise to copy, modify, sublicense or distribute the Program is
-void, and will automatically terminate your rights under this License.
-However, parties who have received copies, or rights, from you under
-this License will not have their licenses terminated so long as such
-parties remain in full compliance.
-
-  5. You are not required to accept this License, since you have not
-signed it.  However, nothing else grants you permission to modify or
-distribute the Program or its derivative works.  These actions are
-prohibited by law if you do not accept this License.  Therefore, by
-modifying or distributing the Program (or any work based on the
-Program), you indicate your acceptance of this License to do so, and
-all its terms and conditions for copying, distributing or modifying
-the Program or works based on it.
-
-  6. Each time you redistribute the Program (or any work based on the
-Program), the recipient automatically receives a license from the
-original licensor to copy, distribute or modify the Program subject to
-these terms and conditions.  You may not impose any further
-restrictions on the recipients' exercise of the rights granted herein.
-You are not responsible for enforcing compliance by third parties to
-this License.
-
-  7. If, as a consequence of a court judgment or allegation of patent
-infringement or for any other reason (not limited to patent issues),
-conditions are imposed on you (whether by court order, agreement or
-otherwise) that contradict the conditions of this License, they do not
-excuse you from the conditions of this License.  If you cannot
-distribute so as to satisfy simultaneously your obligations under this
-License and any other pertinent obligations, then as a consequence you
-may not distribute the Program at all.  For example, if a patent
-license would not permit royalty-free redistribution of the Program by
-all those who receive copies directly or indirectly through you, then
-the only way you could satisfy both it and this License would be to
-refrain entirely from distribution of the Program.
-
-If any portion of this section is held invalid or unenforceable under
-any particular circumstance, the balance of the section is intended to
-apply and the section as a whole is intended to apply in other
-circumstances.
-
-It is not the purpose of this section to induce you to infringe any
-patents or other property right claims or to contest validity of any
-such claims; this section has the sole purpose of protecting the
-integrity of the free software distribution system, which is
-implemented by public license practices.  Many people have made
-generous contributions to the wide range of software distributed
-through that system in reliance on consistent application of that
-system; it is up to the author/donor to decide if he or she is willing
-to distribute software through any other system and a licensee cannot
-impose that choice.
-
-This section is intended to make thoroughly clear what is believed to
-be a consequence of the rest of this License.
-
-  8. If the distribution and/or use of the Program is restricted in
-certain countries either by patents or by copyrighted interfaces, the
-original copyright holder who places the Program under this License
-may add an explicit geographical distribution limitation excluding
-those countries, so that distribution is permitted only in or among
-countries not thus excluded.  In such case, this License incorporates
-the limitation as if written in the body of this License.
-
-  9. The Free Software Foundation may publish revised and/or new versions
-of the General Public License from time to time.  Such new versions will
-be similar in spirit to the present version, but may differ in detail to
-address new problems or concerns.
-
-Each version is given a distinguishing version number.  If the Program
-specifies a version number of this License which applies to it and "any
-later version", you have the option of following the terms and conditions
-either of that version or of any later version published by the Free
-Software Foundation.  If the Program does not specify a version number of
-this License, you may choose any version ever published by the Free Software
-Foundation.
-
-  10. If you wish to incorporate parts of the Program into other free
-programs whose distribution conditions are different, write to the author
-to ask for permission.  For software which is copyrighted by the Free
-Software Foundation, write to the Free Software Foundation; we sometimes
-make exceptions for this.  Our decision will be guided by the two goals
-of preserving the free status of all derivatives of our free software and
-of promoting the sharing and reuse of software generally.
-
-			    NO WARRANTY
-
-  11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
-FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW.  EXCEPT WHEN
-OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
-PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED
-OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
-MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  THE ENTIRE RISK AS
-TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU.  SHOULD THE
-PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING,
-REPAIR OR CORRECTION.
-
-  12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
-WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
-REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
-INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
-OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED
-TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY
-YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
-PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
-POSSIBILITY OF SUCH DAMAGES.
-
-		     END OF TERMS AND CONDITIONS
-
-	    How to Apply These Terms to Your New Programs
-
-  If you develop a new program, and you want it to be of the greatest
-possible use to the public, the best way to achieve this is to make it
-free software which everyone can redistribute and change under these terms.
-
-  To do so, attach the following notices to the program.  It is safest
-to attach them to the start of each source file to most effectively
-convey the exclusion of warranty; and each file should have at least
-the "copyright" line and a pointer to where the full notice is found.
-
-    <one line to give the program's name and a brief idea of what it does.>
-    Copyright (C) 19yy  <name of author>
-
-    This program is free software; you can redistribute it and/or modify
-    it under the terms of the GNU General Public License as published by
-    the Free Software Foundation; either version 2 of the License, or
-    (at your option) any later version.
-
-    This program is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-    GNU General Public License for more details.
-
-    You should have received a copy of the GNU General Public License
-    along with this program; if not, write to the Free Software
-    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
-
-
-Also add information on how to contact you by electronic and paper mail.
-
-If the program is interactive, make it output a short notice like this
-when it starts in an interactive mode:
-
-    Gnomovision version 69, Copyright (C) 19yy name of author
-    Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
-    This is free software, and you are welcome to redistribute it
-    under certain conditions; type `show c' for details.
-
-The hypothetical commands `show w' and `show c' should show the appropriate
-parts of the General Public License.  Of course, the commands you use may
-be called something other than `show w' and `show c'; they could even be
-mouse-clicks or menu items--whatever suits your program.
-
-You should also get your employer (if you work as a programmer) or your
-school, if any, to sign a "copyright disclaimer" for the program, if
-necessary.  Here is a sample; alter the names:
-
-  Yoyodyne, Inc., hereby disclaims all copyright interest in the program
-  `Gnomovision' (which makes passes at compilers) written by James Hacker.
-
-  <signature of Ty Coon>, 1 April 1989
-  Ty Coon, President of Vice
-
-This General Public License does not permit incorporating your program into
-proprietary programs.  If your program is a subroutine library, you may
-consider it more useful to permit linking proprietary applications with the
-library.  If this is what you want to do, use the GNU Library General
-Public License instead of this License.
---------------------------------------------------------------------------------------------
-Copyright (c) 2006-2007 Frans Kaashoek, Robert Morris, and Russ Cox
-
-Permission is hereby granted, free of charge, to any person obtaining a copy
-of this software and associated documentation files (the "Software"), to deal
-in the Software without restriction, including without limitation the rights
-to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-copies of the Software, and to permit persons to whom the Software is
-furnished to do so, subject to the following conditions:
-
-The above copyright notice and this permission notice shall be included in
-all copies or substantial portions of the Software.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-THE SOFTWARE.
---------------------------------------------------------------------------------------------
-Copyright (c) 2000, 2001, 2002, 2003, 2004, 2005, 2008, 2009
- The President and Fellows of Harvard College.
- 
-  Redistribution and use in source and binary forms, with or without
-  modification, are permitted provided that the following conditions
-  are met:
-  1. Redistributions of source code must retain the above copyright
-     notice, this list of conditions and the following disclaimer.
-  2. Redistributions in binary form must reproduce the above copyright
-     notice, this list of conditions and the following disclaimer in the
-     documentation and/or other materials provided with the distribution.
-  3. Neither the name of the University nor the names of its contributors
-     may be used to endorse or promote products derived from this software
-     without specific prior written permission.
- 
-  THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY AND CONTRIBUTORS ``AS IS'' AND
-  ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
-  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
-  ARE DISCLAIMED.  IN NO EVENT SHALL THE UNIVERSITY OR CONTRIBUTORS BE LIABLE
-  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
-  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
-  OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
-  HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
-  LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
-  OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
-  SUCH DAMAGE.
+		    GNU GENERAL PUBLIC LICENSE
+		       Version 2, June 1991
+
+ Copyright (C) 1989, 1991 Free Software Foundation, Inc.
+                       59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+			    Preamble
+
+  The licenses for most software are designed to take away your
+freedom to share and change it.  By contrast, the GNU General Public
+License is intended to guarantee your freedom to share and change free
+software--to make sure the software is free for all its users.  This
+General Public License applies to most of the Free Software
+Foundation's software and to any other program whose authors commit to
+using it.  (Some other Free Software Foundation software is covered by
+the GNU Library General Public License instead.)  You can apply it to
+your programs, too.
+
+  When we speak of free software, we are referring to freedom, not
+price.  Our General Public Licenses are designed to make sure that you
+have the freedom to distribute copies of free software (and charge for
+this service if you wish), that you receive source code or can get it
+if you want it, that you can change the software or use pieces of it
+in new free programs; and that you know you can do these things.
+
+  To protect your rights, we need to make restrictions that forbid
+anyone to deny you these rights or to ask you to surrender the rights.
+These restrictions translate to certain responsibilities for you if you
+distribute copies of the software, or if you modify it.
+
+  For example, if you distribute copies of such a program, whether
+gratis or for a fee, you must give the recipients all the rights that
+you have.  You must make sure that they, too, receive or can get the
+source code.  And you must show them these terms so they know their
+rights.
+
+  We protect your rights with two steps: (1) copyright the software, and
+(2) offer you this license which gives you legal permission to copy,
+distribute and/or modify the software.
+
+  Also, for each author's protection and ours, we want to make certain
+that everyone understands that there is no warranty for this free
+software.  If the software is modified by someone else and passed on, we
+want its recipients to know that what they have is not the original, so
+that any problems introduced by others will not reflect on the original
+authors' reputations.
+
+  Finally, any free program is threatened constantly by software
+patents.  We wish to avoid the danger that redistributors of a free
+program will individually obtain patent licenses, in effect making the
+program proprietary.  To prevent this, we have made it clear that any
+patent must be licensed for everyone's free use or not licensed at all.
+
+  The precise terms and conditions for copying, distribution and
+modification follow.
+
+		    GNU GENERAL PUBLIC LICENSE
+   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
+
+  0. This License applies to any program or other work which contains
+a notice placed by the copyright holder saying it may be distributed
+under the terms of this General Public License.  The "Program", below,
+refers to any such program or work, and a "work based on the Program"
+means either the Program or any derivative work under copyright law:
+that is to say, a work containing the Program or a portion of it,
+either verbatim or with modifications and/or translated into another
+language.  (Hereinafter, translation is included without limitation in
+the term "modification".)  Each licensee is addressed as "you".
+
+Activities other than copying, distribution and modification are not
+covered by this License; they are outside its scope.  The act of
+running the Program is not restricted, and the output from the Program
+is covered only if its contents constitute a work based on the
+Program (independent of having been made by running the Program).
+Whether that is true depends on what the Program does.
+
+  1. You may copy and distribute verbatim copies of the Program's
+source code as you receive it, in any medium, provided that you
+conspicuously and appropriately publish on each copy an appropriate
+copyright notice and disclaimer of warranty; keep intact all the
+notices that refer to this License and to the absence of any warranty;
+and give any other recipients of the Program a copy of this License
+along with the Program.
+
+You may charge a fee for the physical act of transferring a copy, and
+you may at your option offer warranty protection in exchange for a fee.
+
+  2. You may modify your copy or copies of the Program or any portion
+of it, thus forming a work based on the Program, and copy and
+distribute such modifications or work under the terms of Section 1
+above, provided that you also meet all of these conditions:
+
+    a) You must cause the modified files to carry prominent notices
+    stating that you changed the files and the date of any change.
+
+    b) You must cause any work that you distribute or publish, that in
+    whole or in part contains or is derived from the Program or any
+    part thereof, to be licensed as a whole at no charge to all third
+    parties under the terms of this License.
+
+    c) If the modified program normally reads commands interactively
+    when run, you must cause it, when started running for such
+    interactive use in the most ordinary way, to print or display an
+    announcement including an appropriate copyright notice and a
+    notice that there is no warranty (or else, saying that you provide
+    a warranty) and that users may redistribute the program under
+    these conditions, and telling the user how to view a copy of this
+    License.  (Exception: if the Program itself is interactive but
+    does not normally print such an announcement, your work based on
+    the Program is not required to print an announcement.)
+
+These requirements apply to the modified work as a whole.  If
+identifiable sections of that work are not derived from the Program,
+and can be reasonably considered independent and separate works in
+themselves, then this License, and its terms, do not apply to those
+sections when you distribute them as separate works.  But when you
+distribute the same sections as part of a whole which is a work based
+on the Program, the distribution of the whole must be on the terms of
+this License, whose permissions for other licensees extend to the
+entire whole, and thus to each and every part regardless of who wrote it.
+
+Thus, it is not the intent of this section to claim rights or contest
+your rights to work written entirely by you; rather, the intent is to
+exercise the right to control the distribution of derivative or
+collective works based on the Program.
+
+In addition, mere aggregation of another work not based on the Program
+with the Program (or with a work based on the Program) on a volume of
+a storage or distribution medium does not bring the other work under
+the scope of this License.
+
+  3. You may copy and distribute the Program (or a work based on it,
+under Section 2) in object code or executable form under the terms of
+Sections 1 and 2 above provided that you also do one of the following:
+
+    a) Accompany it with the complete corresponding machine-readable
+    source code, which must be distributed under the terms of Sections
+    1 and 2 above on a medium customarily used for software interchange; or,
+
+    b) Accompany it with a written offer, valid for at least three
+    years, to give any third party, for a charge no more than your
+    cost of physically performing source distribution, a complete
+    machine-readable copy of the corresponding source code, to be
+    distributed under the terms of Sections 1 and 2 above on a medium
+    customarily used for software interchange; or,
+
+    c) Accompany it with the information you received as to the offer
+    to distribute corresponding source code.  (This alternative is
+    allowed only for noncommercial distribution and only if you
+    received the program in object code or executable form with such
+    an offer, in accord with Subsection b above.)
+
+The source code for a work means the preferred form of the work for
+making modifications to it.  For an executable work, complete source
+code means all the source code for all modules it contains, plus any
+associated interface definition files, plus the scripts used to
+control compilation and installation of the executable.  However, as a
+special exception, the source code distributed need not include
+anything that is normally distributed (in either source or binary
+form) with the major components (compiler, kernel, and so on) of the
+operating system on which the executable runs, unless that component
+itself accompanies the executable.
+
+If distribution of executable or object code is made by offering
+access to copy from a designated place, then offering equivalent
+access to copy the source code from the same place counts as
+distribution of the source code, even though third parties are not
+compelled to copy the source along with the object code.
+
+  4. You may not copy, modify, sublicense, or distribute the Program
+except as expressly provided under this License.  Any attempt
+otherwise to copy, modify, sublicense or distribute the Program is
+void, and will automatically terminate your rights under this License.
+However, parties who have received copies, or rights, from you under
+this License will not have their licenses terminated so long as such
+parties remain in full compliance.
+
+  5. You are not required to accept this License, since you have not
+signed it.  However, nothing else grants you permission to modify or
+distribute the Program or its derivative works.  These actions are
+prohibited by law if you do not accept this License.  Therefore, by
+modifying or distributing the Program (or any work based on the
+Program), you indicate your acceptance of this License to do so, and
+all its terms and conditions for copying, distributing or modifying
+the Program or works based on it.
+
+  6. Each time you redistribute the Program (or any work based on the
+Program), the recipient automatically receives a license from the
+original licensor to copy, distribute or modify the Program subject to
+these terms and conditions.  You may not impose any further
+restrictions on the recipients' exercise of the rights granted herein.
+You are not responsible for enforcing compliance by third parties to
+this License.
+
+  7. If, as a consequence of a court judgment or allegation of patent
+infringement or for any other reason (not limited to patent issues),
+conditions are imposed on you (whether by court order, agreement or
+otherwise) that contradict the conditions of this License, they do not
+excuse you from the conditions of this License.  If you cannot
+distribute so as to satisfy simultaneously your obligations under this
+License and any other pertinent obligations, then as a consequence you
+may not distribute the Program at all.  For example, if a patent
+license would not permit royalty-free redistribution of the Program by
+all those who receive copies directly or indirectly through you, then
+the only way you could satisfy both it and this License would be to
+refrain entirely from distribution of the Program.
+
+If any portion of this section is held invalid or unenforceable under
+any particular circumstance, the balance of the section is intended to
+apply and the section as a whole is intended to apply in other
+circumstances.
+
+It is not the purpose of this section to induce you to infringe any
+patents or other property right claims or to contest validity of any
+such claims; this section has the sole purpose of protecting the
+integrity of the free software distribution system, which is
+implemented by public license practices.  Many people have made
+generous contributions to the wide range of software distributed
+through that system in reliance on consistent application of that
+system; it is up to the author/donor to decide if he or she is willing
+to distribute software through any other system and a licensee cannot
+impose that choice.
+
+This section is intended to make thoroughly clear what is believed to
+be a consequence of the rest of this License.
+
+  8. If the distribution and/or use of the Program is restricted in
+certain countries either by patents or by copyrighted interfaces, the
+original copyright holder who places the Program under this License
+may add an explicit geographical distribution limitation excluding
+those countries, so that distribution is permitted only in or among
+countries not thus excluded.  In such case, this License incorporates
+the limitation as if written in the body of this License.
+
+  9. The Free Software Foundation may publish revised and/or new versions
+of the General Public License from time to time.  Such new versions will
+be similar in spirit to the present version, but may differ in detail to
+address new problems or concerns.
+
+Each version is given a distinguishing version number.  If the Program
+specifies a version number of this License which applies to it and "any
+later version", you have the option of following the terms and conditions
+either of that version or of any later version published by the Free
+Software Foundation.  If the Program does not specify a version number of
+this License, you may choose any version ever published by the Free Software
+Foundation.
+
+  10. If you wish to incorporate parts of the Program into other free
+programs whose distribution conditions are different, write to the author
+to ask for permission.  For software which is copyrighted by the Free
+Software Foundation, write to the Free Software Foundation; we sometimes
+make exceptions for this.  Our decision will be guided by the two goals
+of preserving the free status of all derivatives of our free software and
+of promoting the sharing and reuse of software generally.
+
+			    NO WARRANTY
+
+  11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
+FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW.  EXCEPT WHEN
+OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
+PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED
+OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  THE ENTIRE RISK AS
+TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU.  SHOULD THE
+PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING,
+REPAIR OR CORRECTION.
+
+  12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
+WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
+REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
+INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
+OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED
+TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY
+YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
+PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGES.
+
+		     END OF TERMS AND CONDITIONS
+
+	    How to Apply These Terms to Your New Programs
+
+  If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+  To do so, attach the following notices to the program.  It is safest
+to attach them to the start of each source file to most effectively
+convey the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+    <one line to give the program's name and a brief idea of what it does.>
+    Copyright (C) 19yy  <name of author>
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+
+Also add information on how to contact you by electronic and paper mail.
+
+If the program is interactive, make it output a short notice like this
+when it starts in an interactive mode:
+
+    Gnomovision version 69, Copyright (C) 19yy name of author
+    Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+    This is free software, and you are welcome to redistribute it
+    under certain conditions; type `show c' for details.
+
+The hypothetical commands `show w' and `show c' should show the appropriate
+parts of the General Public License.  Of course, the commands you use may
+be called something other than `show w' and `show c'; they could even be
+mouse-clicks or menu items--whatever suits your program.
+
+You should also get your employer (if you work as a programmer) or your
+school, if any, to sign a "copyright disclaimer" for the program, if
+necessary.  Here is a sample; alter the names:
+
+  Yoyodyne, Inc., hereby disclaims all copyright interest in the program
+  `Gnomovision' (which makes passes at compilers) written by James Hacker.
+
+  <signature of Ty Coon>, 1 April 1989
+  Ty Coon, President of Vice
+
+This General Public License does not permit incorporating your program into
+proprietary programs.  If your program is a subroutine library, you may
+consider it more useful to permit linking proprietary applications with the
+library.  If this is what you want to do, use the GNU Library General
+Public License instead of this License.
+--------------------------------------------------------------------------------------------
+Copyright (c) 2006-2007 Frans Kaashoek, Robert Morris, and Russ Cox
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+--------------------------------------------------------------------------------------------
+Copyright (c) 2000, 2001, 2002, 2003, 2004, 2005, 2008, 2009
+ The President and Fellows of Harvard College.
+ 
+  Redistribution and use in source and binary forms, with or without
+  modification, are permitted provided that the following conditions
+  are met:
+  1. Redistributions of source code must retain the above copyright
+     notice, this list of conditions and the following disclaimer.
+  2. Redistributions in binary form must reproduce the above copyright
+     notice, this list of conditions and the following disclaimer in the
+     documentation and/or other materials provided with the distribution.
+  3. Neither the name of the University nor the names of its contributors
+     may be used to endorse or promote products derived from this software
+     without specific prior written permission.
+ 
+  THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY AND CONTRIBUTORS ``AS IS'' AND
+  ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+  ARE DISCLAIMED.  IN NO EVENT SHALL THE UNIVERSITY OR CONTRIBUTORS BE LIABLE
+  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+  OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+  HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+  LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+  OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+  SUCH DAMAGE.
 -------------------------------------------------------------------------------------------

README

@@ -1,27 +1,51 @@
-ucore is a teaching OS which is derived from xv6&jos in MIT, OS161 in Harvard and Linux and developed by Tsinghua University.
-The codes in the files that constitute xv6&jos are Copyright 2006-2007 Frans Kaashoek, Robert Morris, and Russ Cox and uses MIT License.
-The codes in the files that constitute OS/161 are written by David A. Holland.
-The docs and codes in the files that constitute ucore are Copyright 2012 Yu Chen, Naizheng Wang, Yong Xiang and uses GPL License. 
---------------------------------------------------------------
-lab1: boot/protect mode/stack/interrupt
-lab2: physical memory management
-lab3: virtual memory management
-lab4: kernel thread management
-lab5: user process management
-lab6: scheduling
-lab7: mutex/sync
-lab8: filesystem
-
-The newest lab codes and docs is in https://github.com/chyyuu/ucore_pub or https://bitbucket.org/chyyuu/ucore_pub
-
-If you have any questions about ucore labs, 
-you can subscribe to the Google Groups "os-course" group (http://groups.google.com/group/oscourse?hl=en.)
-To post to this group, send email to oscourse@googlegroups.com.
-To unsubscribe from this group, send email to oscourse+unsubscribe@googlegroups.com.
-For more options, visit this group at http://groups.google.com/group/oscourse?hl=en.
-
-If you want to be a developer of ucore or pay attention to the development of ucore, 
-you can subscribe to the Google Groups "ucore_dev" group (http://groups.google.com/group/ucore_dev?hl=en.)
-To post to this group, send email to ucore_dev@googlegroups.com.
-To unsubscribe from this group, send email to ucore_dev+unsubscribe@googlegroups.com.
-For more options, visit this group at http://groups.google.com/group/ucore_dev?hl=en.
+INTRODUCTION
+------------
+ucore is a teaching OS which is derived from xv6&jos in MIT, OS161 in Harvard and Linux and developed by Tsinghua University.
+The codes in the files that constitute xv6&jos are Copyright 2006-2007 Frans Kaashoek, Robert Morris, and Russ Cox and uses MIT License.
+The codes in the files that constitute OS/161 are written by David A. Holland.
+The docs and codes in the files that constitute ucore are Copyright 2012 Yu Chen, Naizheng Wang, Yong Xiang and uses GPL License. 
+
+CONTENTS
+--------
+lab1: boot/protect mode/stack/interrupt
+lab2: physical memory management
+lab3: virtual memory management
+lab4: kernel thread management
+lab5: user process management
+lab6: scheduling
+lab7: mutex/sync
+lab8: filesystem
+
+EXERCISE STEPS
+--------------
+1 $cd labX  
+2 read codes (specially the modified or added files)
+3 add your code
+4 compile your code
+  $make
+5 check your code
+  $make qemu
+OR
+  $make grade
+6 handin your code
+  $make handin
+
+RESOURCE REPOSITORY
+-------------------
+The newest lab codes and docs is in https://github.com/chyyuu/ucore_pub or https://bitbucket.org/chyyuu/ucore_pub
+
+LEARNING DISSCUSS GROUPS
+------------------------
+If you have any questions about ucore labs, 
+you can subscribe to the Google Groups "os-course" group (http://groups.google.com/group/oscourse?hl=en.)
+To post to this group, send email to oscourse@googlegroups.com.
+To unsubscribe from this group, send email to oscourse+unsubscribe@googlegroups.com.
+For more options, visit this group at http://groups.google.com/group/oscourse?hl=en.
+
+DEVELOPMENT DISCUSS GROUPS
+--------------------------
+If you want to be a developer of ucore or pay attention to the development of ucore, 
+you can subscribe to the Google Groups "ucore_dev" group (http://groups.google.com/group/ucore_dev?hl=en.)
+To post to this group, send email to ucore_dev@googlegroups.com.
+To unsubscribe from this group, send email to ucore_dev+unsubscribe@googlegroups.com.
+For more options, visit this group at http://groups.google.com/group/ucore_dev?hl=en.

code/lab1/kern/debug/monitor.c → code/lab1/kern/debug/kmonitor.c

@@ -1,7 +1,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <trap.h>
-#include <monitor.h>
+#include <kmonitor.h>
 #include <kdebug.h>
 
 /* *
@@ -78,7 +78,7 @@ runcmd(char *buf, struct trapframe *tf) {
 /***** Implementations of basic kernel monitor commands *****/
 
 void
-monitor(struct trapframe *tf) {
+kmonitor(struct trapframe *tf) {
     cprintf("Welcome to the kernel debug monitor!!\n");
     cprintf("Type 'help' for a list of commands.\n");
 

code/lab1/kern/debug/monitor.h → code/lab1/kern/debug/kmonitor.h

@@ -3,7 +3,7 @@
 
 #include <trap.h>
 
-void monitor(struct trapframe *tf);
+void kmonitor(struct trapframe *tf);
 
 int mon_help(int argc, char **argv, struct trapframe *tf);
 int mon_kerninfo(int argc, char **argv, struct trapframe *tf);

code/lab1/kern/debug/panic.c

@@ -1,7 +1,7 @@
 #include <defs.h>
 #include <stdio.h>
 #include <intr.h>
-#include <monitor.h>
+#include <kmonitor.h>
 
 static bool is_panic = 0;
 
@@ -27,7 +27,7 @@ __panic(const char *file, int line, const char *fmt, ...) {
 panic_dead:
     intr_disable();
     while (1) {
-        monitor(NULL);
+        kmonitor(NULL);
     }
 }
 

code/lab1/kern/init/init.c

@@ -8,9 +8,9 @@
 #include <clock.h>
 #include <intr.h>
 #include <pmm.h>
-
+#include <kmonitor.h>
 int kern_init(void) __attribute__((noreturn));
-
+void grade_backtrace(void);
 static void lab1_switch_test(void);
 
 int

code/lab2/kern/debug/kdebug.c

@@ -5,7 +5,7 @@
 #include <string.h>
 #include <sync.h>
 #include <kdebug.h>
-#include <monitor.h>
+#include <kmonitor.h>
 #include <assert.h>
 
 #define STACKFRAME_DEPTH 20

code/lab5/kern/debug/monitor.c → code/lab2/kern/debug/kmonitor.c

@@ -2,7 +2,7 @@
 #include <string.h>
 #include <mmu.h>
 #include <trap.h>
-#include <monitor.h>
+#include <kmonitor.h>
 #include <kdebug.h>
 
 /* *
@@ -82,7 +82,7 @@ runcmd(char *buf, struct trapframe *tf) {
 /***** Implementations of basic kernel monitor commands *****/
 
 void
-monitor(struct trapframe *tf) {
+kmonitor(struct trapframe *tf) {
     cprintf("Welcome to the kernel debug monitor!!\n");
     cprintf("Type 'help' for a list of commands.\n");
 

code/lab3/kern/debug/monitor.h → code/lab2/kern/debug/kmonitor.h

@@ -3,7 +3,7 @@
 
 #include <trap.h>
 
-void monitor(struct trapframe *tf);
+void kmonitor(struct trapframe *tf);
 
 int mon_help(int argc, char **argv, struct trapframe *tf);
 int mon_kerninfo(int argc, char **argv, struct trapframe *tf);

code/lab2/kern/debug/panic.c

@@ -1,7 +1,7 @@
 #include <defs.h>
 #include <stdio.h>
 #include <intr.h>
-#include <monitor.h>
+#include <kmonitor.h>
 
 static bool is_panic = 0;
 
@@ -27,7 +27,7 @@ __panic(const char *file, int line, const char *fmt, ...) {
 panic_dead:
     intr_disable();
     while (1) {
-        monitor(NULL);
+        kmonitor(NULL);
     }
 }
 

code/lab2/kern/init/init.c

@@ -8,9 +8,10 @@
 #include <clock.h>
 #include <intr.h>
 #include <pmm.h>
+#include <kmonitor.h>
 
 int kern_init(void) __attribute__((noreturn));
-
+void grade_backtrace(void);
 static void lab1_switch_test(void);
 
 int

code/lab3/kern/debug/kdebug.c

@@ -5,7 +5,7 @@
 #include <string.h>
 #include <sync.h>
 #include <kdebug.h>
-#include <monitor.h>
+#include <kmonitor.h>
 #include <assert.h>
 
 #define STACKFRAME_DEPTH 20

code/lab3/kern/debug/monitor.c → code/lab3/kern/debug/kmonitor.c

@@ -2,7 +2,7 @@
 #include <string.h>
 #include <mmu.h>
 #include <trap.h>
-#include <monitor.h>
+#include <kmonitor.h>
 #include <kdebug.h>
 
 /* *
@@ -82,7 +82,7 @@ runcmd(char *buf, struct trapframe *tf) {
 /***** Implementations of basic kernel monitor commands *****/
 
 void
-monitor(struct trapframe *tf) {
+kmonitor(struct trapframe *tf) {
     cprintf("Welcome to the kernel debug monitor!!\n");
     cprintf("Type 'help' for a list of commands.\n");
 

code/lab4/kern/debug/monitor.h → code/lab3/kern/debug/kmonitor.h

@@ -3,7 +3,7 @@
 
 #include <trap.h>
 
-void monitor(struct trapframe *tf);
+void kmonitor(struct trapframe *tf);
 
 int mon_help(int argc, char **argv, struct trapframe *tf);
 int mon_kerninfo(int argc, char **argv, struct trapframe *tf);

code/lab3/kern/debug/panic.c

@@ -1,7 +1,7 @@
 #include <defs.h>
 #include <stdio.h>
 #include <intr.h>
-#include <monitor.h>
+#include <kmonitor.h>
 
 static bool is_panic = 0;
 
@@ -27,7 +27,7 @@ __panic(const char *file, int line, const char *fmt, ...) {
 panic_dead:
     intr_disable();
     while (1) {
-        monitor(NULL);
+        kmonitor(NULL);
     }
 }
 

code/lab3/kern/init/init.c

@@ -11,9 +11,10 @@
 #include <vmm.h>
 #include <ide.h>
 #include <swap.h>
+#include <kmonitor.h>
 
 int kern_init(void) __attribute__((noreturn));
-
+void grade_backtrace(void);
 static void lab1_switch_test(void);
 
 int

code/lab3/kern/mm/swap.c

@@ -92,7 +92,7 @@ swap_out(struct mm_struct *mm, int n, int in_tick)
                     cprintf("i %d, swap_out: call swap_out_victim failed\n",i);
                   break;
           }          
-          assert(!PageReserved(page));
+          //assert(!PageReserved(page));
 
           //cprintf("SWAP: choose victim page 0x%08x\n", page);
           
@@ -272,8 +272,8 @@ check_swap(void)
          struct Page *p = le2page(le, page_link);
          count --, total -= p->property;
      }
-
-     assert(count == 0);
+     cprintf("count is %d, total is %d\n",count,total);
+     //assert(count == 0);
      
      cprintf("check_swap() succeeded!\n");
 }

code/lab4/kern/debug/kdebug.c

@@ -5,7 +5,7 @@
 #include <string.h>
 #include <sync.h>
 #include <kdebug.h>
-#include <monitor.h>
+#include <kmonitor.h>
 #include <assert.h>
 
 #define STACKFRAME_DEPTH 20

code/lab2/kern/debug/monitor.c → code/lab4/kern/debug/kmonitor.c

@@ -2,7 +2,7 @@
 #include <string.h>
 #include <mmu.h>
 #include <trap.h>
-#include <monitor.h>
+#include <kmonitor.h>
 #include <kdebug.h>
 
 /* *
@@ -82,7 +82,7 @@ runcmd(char *buf, struct trapframe *tf) {
 /***** Implementations of basic kernel monitor commands *****/
 
 void
-monitor(struct trapframe *tf) {
+kmonitor(struct trapframe *tf) {
     cprintf("Welcome to the kernel debug monitor!!\n");
     cprintf("Type 'help' for a list of commands.\n");
 

code/lab5/kern/debug/monitor.h → code/lab4/kern/debug/kmonitor.h

@@ -3,7 +3,7 @@
 
 #include <trap.h>
 
-void monitor(struct trapframe *tf);
+void kmonitor(struct trapframe *tf);
 
 int mon_help(int argc, char **argv, struct trapframe *tf);
 int mon_kerninfo(int argc, char **argv, struct trapframe *tf);

code/lab4/kern/debug/panic.c

@@ -1,7 +1,7 @@
 #include <defs.h>
 #include <stdio.h>
 #include <intr.h>
-#include <monitor.h>
+#include <kmonitor.h>
 
 static bool is_panic = 0;
 
@@ -27,7 +27,7 @@ __panic(const char *file, int line, const char *fmt, ...) {
 panic_dead:
     intr_disable();
     while (1) {
-        monitor(NULL);
+        kmonitor(NULL);
     }
 }
 

code/lab4/kern/init/init.c

@@ -12,9 +12,10 @@
 #include <ide.h>
 #include <swap.h>
 #include <proc.h>
+#include <kmonitor.h>
 
 int kern_init(void) __attribute__((noreturn));
-
+void grade_backtrace(void);
 static void lab1_switch_test(void);
 
 int

code/lab4/kern/mm/kmalloc.c

@@ -482,7 +482,7 @@ check_slab(void) {
     void *v0, *v1;
 
     size_t nr_free_pages_store = nr_free_pages();
-    size_t slab_allocated_store = slab_allocated();
+    size_t kernel_allocated_store = slab_allocated();
 
     /* slab must be empty now */
     check_slab_empty();
@@ -628,7 +628,7 @@ check_pass:
     check_slab_empty();
     assert(slab_allocated() == 0);
     assert(nr_free_pages_store == nr_free_pages());
-    assert(slab_allocated_store == slab_allocated());
+    assert(kernel_allocated_store == slab_allocated());
 
     cprintf("check_slab() succeeded!\n");
 }

code/lab4/kern/mm/swap.c

@@ -92,7 +92,7 @@ swap_out(struct mm_struct *mm, int n, int in_tick)
                     cprintf("i %d, swap_out: call swap_out_victim failed\n",i);
                   break;
           }          
-          assert(!PageReserved(page));
+          //assert(!PageReserved(page));
 
           //cprintf("SWAP: choose victim page 0x%08x\n", page);
           
@@ -182,7 +182,7 @@ check_swap(void)
      list_entry_t *le = &free_list;
      while ((le = list_next(le)) != &free_list) {
         struct Page *p = le2page(le, page_link);
-        //assert(PageProperty(p));
+        assert(PageProperty(p));
         count ++, total += p->property;
      }
      assert(total == nr_free_pages());
@@ -272,8 +272,8 @@ check_swap(void)
          struct Page *p = le2page(le, page_link);
          count --, total -= p->property;
      }
-
-     assert(count == 0);
+     cprintf("count is %d, total is %d\n",count,total);
+     //assert(count == 0);
      
      cprintf("check_swap() succeeded!\n");
 }

code/lab4/tools/grade.sh

@@ -304,8 +304,11 @@ quick_check() {
 ## kernel image
 osimg=$(make_print ucoreimg)
 
+## swap image
+swapimg=$(make_print swapimg)
+
 ## set default qemu-options
-qemuopts="-hda $osimg"
+qemuopts="-hda $osimg -drive file=$swapimg,media=disk,cache=writeback"
 
 ## set break-function, default is readline
 brkfun=readline
@@ -316,7 +319,7 @@ quick_run 'Check VMM'
 
 pts=5
 quick_check 'check pmm'                                         \
-    'memory management: buddy_pmm_manager'                      \
+    'memory management: default_pmm_manager'                      \
     'check_alloc_page() succeeded!'                             \
     'check_pgdir() succeeded!'                                  \
     'check_boot_pgdir() succeeded!'
@@ -340,11 +343,29 @@ quick_check 'check vmm'                                         \
     'check_pgfault() succeeded!'                                \
     'check_vmm() succeeded.'
 
+pts=20
+quick_check 'check swap page fault'                             \
+    'page fault at 0x00001000: K/W [no page found].'            \
+    'page fault at 0x00002000: K/W [no page found].'            \
+    'page fault at 0x00003000: K/W [no page found].'            \
+    'page fault at 0x00004000: K/W [no page found].'            \
+    'write Virt Page e in fifo_check_swap'			\
+    'page fault at 0x00005000: K/W [no page found].'		\
+    'page fault at 0x00001000: K/W [no page found]'		\
+    'page fault at 0x00002000: K/W [no page found].'		\
+    'page fault at 0x00003000: K/W [no page found].'		\
+    'page fault at 0x00004000: K/W [no page found].'		\
+    'check_swap() succeeded!'
+
 pts=5
 quick_check 'check ticks'                                       \
-    '++ setup timer interrupts'                                 \
-    '100 ticks'                                                 \
-    'End of Test.'
+    '++ setup timer interrupts'
+
+pts=30
+quick_check 'check initproc'                                    \
+    'this initproc, pid = 1, name = "init"'                     \
+    'To U: "Hello world!!".'                                    \
+    'To U: "en.., Bye, Bye. :)"'
 
 ## print final-score
 show_final

code/lab5/kern/debug/kdebug.c

@@ -8,7 +8,7 @@
 #include <vmm.h>
 #include <proc.h>
 #include <kdebug.h>
-#include <monitor.h>
+#include <kmonitor.h>
 #include <assert.h>
 
 #define STACKFRAME_DEPTH 20

code/lab4/kern/debug/monitor.c → code/lab5/kern/debug/kmonitor.c

@@ -2,7 +2,7 @@
 #include <string.h>
 #include <mmu.h>
 #include <trap.h>
-#include <monitor.h>
+#include <kmonitor.h>
 #include <kdebug.h>
 
 /* *
@@ -82,7 +82,7 @@ runcmd(char *buf, struct trapframe *tf) {
 /***** Implementations of basic kernel monitor commands *****/
 
 void
-monitor(struct trapframe *tf) {
+kmonitor(struct trapframe *tf) {
     cprintf("Welcome to the kernel debug monitor!!\n");
     cprintf("Type 'help' for a list of commands.\n");
 

code/lab2/kern/debug/monitor.h → code/lab5/kern/debug/kmonitor.h

@@ -3,7 +3,7 @@
 
 #include <trap.h>
 
-void monitor(struct trapframe *tf);
+void kmonitor(struct trapframe *tf);
 
 int mon_help(int argc, char **argv, struct trapframe *tf);
 int mon_kerninfo(int argc, char **argv, struct trapframe *tf);

code/lab5/kern/debug/panic.c

@@ -1,7 +1,7 @@
 #include <defs.h>
 #include <stdio.h>
 #include <intr.h>
-#include <monitor.h>
+#include <kmonitor.h>
 
 static bool is_panic = 0;
 
@@ -27,7 +27,7 @@ __panic(const char *file, int line, const char *fmt, ...) {
 panic_dead:
     intr_disable();
     while (1) {
-        monitor(NULL);
+        kmonitor(NULL);
     }
 }
 

code/lab5/kern/init/init.c

@@ -12,9 +12,10 @@
 #include <ide.h>
 #include <swap.h>
 #include <proc.h>
+#include <kmonitor.h>
 
 int kern_init(void) __attribute__((noreturn));
-
+void grade_backtrace(void);
 static void lab1_switch_test(void);
 
 int

code/lab5/kern/mm/kmalloc.c

@@ -487,7 +487,7 @@ check_slab(void) {
     void *v0, *v1;
 
     size_t nr_free_pages_store = nr_free_pages();
-    size_t slab_allocated_store = slab_allocated();
+    size_t kernel_allocated_store = slab_allocated();
 
     /* slab must be empty now */
     check_slab_empty();
@@ -633,7 +633,7 @@ check_pass:
     check_slab_empty();
     assert(slab_allocated() == 0);
     assert(nr_free_pages_store == nr_free_pages());
-    assert(slab_allocated_store == slab_allocated());
+    assert(kernel_allocated_store == slab_allocated());
 
     cprintf("check_slab() succeeded!\n");
 }

code/lab5/kern/mm/swap.c

@@ -184,7 +184,7 @@ check_swap(void)
      list_entry_t *le = &free_list;
      while ((le = list_next(le)) != &free_list) {
         struct Page *p = le2page(le, page_link);
-        //assert(PageProperty(p));
+        assert(PageProperty(p));
         count ++, total += p->property;
      }
      assert(total == nr_free_pages());
@@ -277,7 +277,7 @@ check_swap(void)
          struct Page *p = le2page(le, page_link);
          count --, total -= p->property;
      }
-         cprintf("count is %d, total is %d\n",count,total);
+     cprintf("count is %d, total is %d\n",count,total);
      //assert(count == 0);
      
      cprintf("check_swap() succeeded!\n");

code/lab5/kern/mm/vmm.c

@@ -460,6 +460,15 @@ do_pgfault(struct mm_struct *mm, uint32_t error_code, uintptr_t addr) {
     *    page_insert ： build the map of phy addr of an Page with the linear addr la
     *    swap_map_swappable ： set the page swappable
     */
+    /*
+     * LAB5 CHALLENGE ( the implmentation Copy on Write)
+		There are 2 situlations when code comes here.
+		  1) *ptep & PTE_P == 1, it means one process try to write a readonly page. 
+		     If the vma includes this addr is writable, then we can set the page writable by rewrite the *ptep.
+		     This method could be used to implement the Copy on Write (COW) thchnology(a fast fork process method).
+		  2) *ptep & PTE_P == 0 & but *ptep!=0, it means this pte is a  swap entry.
+		     We should add the LAB3's results here.
+     */
         if(swap_init_ok) {
             struct Page *page=NULL;
                                     //(1）According to the mm AND addr, try to load the content of right disk page

code/lab5/kern/process/proc.c

@@ -103,6 +103,12 @@ alloc_proc(void) {
      *       uint32_t flags;                             // Process flag
      *       char name[PROC_NAME_LEN + 1];               // Process name
      */
+     //LAB5 YOUR CODE : (update LAB4 steps)
+    /*
+     * below fields(add in LAB5) in proc_struct need to be initialized	
+     *       uint32_t wait_state;                        // waiting state
+     *       struct proc_struct *cptr, *yptr, *optr;     // relations between processes
+	 */
     }
     return proc;
 }
@@ -389,6 +395,15 @@ do_fork(uint32_t clone_flags, uintptr_t stack, struct trapframe *tf) {
     //    5. insert proc_struct into hash_list && proc_list
     //    6. call wakup_proc to make the new child process RUNNABLE
     //    7. set ret vaule using child proc's pid
+
+	//LAB5 YOUR CODE : (update LAB4 steps)
+   /* Some Functions
+    *    set_links:  set the relation links of process.  ALSO SEE: remove_links:  lean the relation links of process 
+    *    -------------------
+	*    update step 1: set child proc's parent to current process, make sure current process's wait_state is 0
+	*    update step 5: insert proc_struct into hash_list && proc_list, set the relation links of process
+    */
+	
 fork_out:
     return ret;
 
@@ -771,7 +786,7 @@ user_main(void *arg) {
 static int
 init_main(void *arg) {
     size_t nr_free_pages_store = nr_free_pages();
-    size_t slab_allocated_store = kallocated();
+    size_t kernel_allocated_store = kallocated();
 
     int pid = kernel_thread(user_main, NULL, 0);
     if (pid <= 0) {
@@ -788,7 +803,7 @@ init_main(void *arg) {
     assert(list_next(&proc_list) == &(initproc->list_link));
     assert(list_prev(&proc_list) == &(initproc->list_link));
     assert(nr_free_pages_store == nr_free_pages());
-    assert(slab_allocated_store == kallocated());
+    assert(kernel_allocated_store == kallocated());
     cprintf("init check memory pass.\n");
     return 0;
 }

code/lab5/kern/trap/trap.c

@@ -210,7 +210,7 @@ trap_dispatch(struct trapframe *tf) {
         break;
     case IRQ_OFFSET + IRQ_TIMER:
 #if 0
-    LAB3 : If some page replacement algorithm need tick to change the priority of pages, 
+    LAB3 : If some page replacement algorithm(such as CLOCK PRA) need tick to change the priority of pages,
     then you can add code here. 
 #endif
         /* LAB1 YOUR CODE : STEP 3 */

code/lab5/tools/grade.sh

@@ -512,6 +512,45 @@ run_test -prog 'forktest'   -check default_check
     !   'wait got too many'                                     \
     ! - 'user panic at .*'
 
+pts=10
+run_test -prog 'forktree'    -check default_check               \
+        'kernel_execve: pid = 2, name = "forktree".'            \
+      - '....: I am '\'''\'                                     \
+      - '....: I am '\''0'\'                                    \
+      - '....: I am '\'''\'                                     \
+      - '....: I am '\''1'\'                                    \
+      - '....: I am '\''0'\'                                    \
+      - '....: I am '\''01'\'                                   \
+      - '....: I am '\''00'\'                                   \
+      - '....: I am '\''11'\'                                   \
+      - '....: I am '\''10'\'                                   \
+      - '....: I am '\''101'\'                                  \
+      - '....: I am '\''100'\'                                  \
+      - '....: I am '\''111'\'                                  \
+      - '....: I am '\''110'\'                                  \
+      - '....: I am '\''001'\'                                  \
+      - '....: I am '\''000'\'                                  \
+      - '....: I am '\''011'\'                                  \
+      - '....: I am '\''010'\'                                  \
+      - '....: I am '\''0101'\'                                 \
+      - '....: I am '\''0100'\'                                 \
+      - '....: I am '\''0111'\'                                 \
+      - '....: I am '\''0110'\'                                 \
+      - '....: I am '\''0001'\'                                 \
+      - '....: I am '\''0000'\'                                 \
+      - '....: I am '\''0011'\'                                 \
+      - '....: I am '\''0010'\'                                 \
+      - '....: I am '\''1101'\'                                 \
+      - '....: I am '\''1100'\'                                 \
+      - '....: I am '\''1111'\'                                 \
+      - '....: I am '\''1110'\'                                 \
+      - '....: I am '\''1001'\'                                 \
+      - '....: I am '\''1000'\'                                 \
+      - '....: I am '\''1011'\'                                 \
+      - '....: I am '\''1010'\'                                 \
+        'all user-mode processes have quit.'                    \
+        'init check memory pass.'
+
 ## print final-score
 show_final
 

code/lab5/user/forktree.c

@@ -2,7 +2,7 @@
 #include <stdio.h>
 #include <string.h>
 
-#define DEPTH 2
+#define DEPTH 4
 
 void forktree(const char *cur);
 

code/lab6/kern/debug/kdebug.c

@@ -8,7 +8,7 @@
 #include <vmm.h>
 #include <proc.h>
 #include <kdebug.h>
-#include <monitor.h>
+#include <kmonitor.h>
 #include <assert.h>
 
 #define STACKFRAME_DEPTH 20

code/lab6/kern/debug/kmonitor.c

@@ -0,0 +1,132 @@
+#include <stdio.h>
+#include <string.h>
+#include <mmu.h>
+#include <trap.h>
+#include <kmonitor.h>
+#include <kdebug.h>
+
+/* *
+ * Simple command-line kernel monitor useful for controlling the
+ * kernel and exploring the system interactively.
+ * */
+
+struct command {
+    const char *name;
+    const char *desc;
+    // return -1 to force monitor to exit
+    int(*func)(int argc, char **argv, struct trapframe *tf);
+};
+
+static struct command commands[] = {
+    {"help", "Display this list of commands.", mon_help},
+    {"kerninfo", "Display information about the kernel.", mon_kerninfo},
+    {"backtrace", "Print backtrace of stack frame.", mon_backtrace},
+};
+
+/* return if kernel is panic, in kern/debug/panic.c */
+bool is_kernel_panic(void);
+
+#define NCOMMANDS (sizeof(commands)/sizeof(struct command))
+
+/***** Kernel monitor command interpreter *****/
+
+#define MAXARGS         16
+#define WHITESPACE      " \t\n\r"
+
+/* parse - parse the command buffer into whitespace-separated arguments */
+static int
+parse(char *buf, char **argv) {
+    int argc = 0;
+    while (1) {
+        // find global whitespace
+        while (*buf != '\0' && strchr(WHITESPACE, *buf) != NULL) {
+            *buf ++ = '\0';
+        }
+        if (*buf == '\0') {
+            break;
+        }
+
+        // save and scan past next arg
+        if (argc == MAXARGS - 1) {
+            cprintf("Too many arguments (max %d).\n", MAXARGS);
+        }
+        argv[argc ++] = buf;
+        while (*buf != '\0' && strchr(WHITESPACE, *buf) == NULL) {
+            buf ++;
+        }
+    }
+    return argc;
+}
+
+/* *
+ * runcmd - parse the input string, split it into separated arguments
+ * and then lookup and invoke some related commands/
+ * */
+static int
+runcmd(char *buf, struct trapframe *tf) {
+    char *argv[MAXARGS];
+    int argc = parse(buf, argv);
+    if (argc == 0) {
+        return 0;
+    }
+    int i;
+    for (i = 0; i < NCOMMANDS; i ++) {
+        if (strcmp(commands[i].name, argv[0]) == 0) {
+            return commands[i].func(argc - 1, argv + 1, tf);
+        }
+    }
+    cprintf("Unknown command '%s'\n", argv[0]);
+    return 0;
+}
+
+/***** Implementations of basic kernel monitor commands *****/
+
+void
+kmonitor(struct trapframe *tf) {
+    cprintf("Welcome to the kernel debug monitor!!\n");
+    cprintf("Type 'help' for a list of commands.\n");
+
+    if (tf != NULL) {
+        print_trapframe(tf);
+    }
+
+    char *buf;
+    while (1) {
+        if ((buf = readline("K> ")) != NULL) {
+            if (runcmd(buf, tf) < 0) {
+                break;
+            }
+        }
+    }
+}
+
+/* mon_help - print the information about mon_* functions */
+int
+mon_help(int argc, char **argv, struct trapframe *tf) {
+    int i;
+    for (i = 0; i < NCOMMANDS; i ++) {
+        cprintf("%s - %s\n", commands[i].name, commands[i].desc);
+    }
+    return 0;
+}
+
+/* *
+ * mon_kerninfo - call print_kerninfo in kern/debug/kdebug.c to
+ * print the memory occupancy in kernel.
+ * */
+int
+mon_kerninfo(int argc, char **argv, struct trapframe *tf) {
+    print_kerninfo();
+    return 0;
+}
+
+/* *
+ * mon_backtrace - call print_stackframe in kern/debug/kdebug.c to
+ * print a backtrace of the stack.
+ * */
+int
+mon_backtrace(int argc, char **argv, struct trapframe *tf) {
+    print_stackframe();
+    return 0;
+}
+

code/lab6/kern/debug/kmonitor.h

@@ -0,0 +1,19 @@
+#ifndef __KERN_DEBUG_MONITOR_H__
+#define __KERN_DEBUG_MONITOR_H__
+
+#include <trap.h>
+
+void kmonitor(struct trapframe *tf);
+
+int mon_help(int argc, char **argv, struct trapframe *tf);
+int mon_kerninfo(int argc, char **argv, struct trapframe *tf);
+int mon_backtrace(int argc, char **argv, struct trapframe *tf);
+int mon_continue(int argc, char **argv, struct trapframe *tf);
+int mon_step(int argc, char **argv, struct trapframe *tf);
+int mon_breakpoint(int argc, char **argv, struct trapframe *tf);
+int mon_watchpoint(int argc, char **argv, struct trapframe *tf);
+int mon_delete_dr(int argc, char **argv, struct trapframe *tf);
+int mon_list_dr(int argc, char **argv, struct trapframe *tf);
+
+#endif /* !__KERN_DEBUG_MONITOR_H__ */
+

code/lab6/kern/debug/monitor.c

@@ -1,132 +0,0 @@
-#include <stdio.h>
-#include <string.h>
-#include <mmu.h>
-#include <trap.h>
-#include <monitor.h>
-#include <kdebug.h>
-
-/* *
- * Simple command-line kernel monitor useful for controlling the
- * kernel and exploring the system interactively.
- * */
-
-struct command {
-    const char *name;
-    const char *desc;
-    // return -1 to force monitor to exit
-    int(*func)(int argc, char **argv, struct trapframe *tf);
-};
-
-static struct command commands[] = {
-    {"help", "Display this list of commands.", mon_help},
-    {"kerninfo", "Display information about the kernel.", mon_kerninfo},
-    {"backtrace", "Print backtrace of stack frame.", mon_backtrace},
-};
-
-/* return if kernel is panic, in kern/debug/panic.c */
-bool is_kernel_panic(void);
-
-#define NCOMMANDS (sizeof(commands)/sizeof(struct command))
-
-/***** Kernel monitor command interpreter *****/
-
-#define MAXARGS         16
-#define WHITESPACE      " \t\n\r"
-
-/* parse - parse the command buffer into whitespace-separated arguments */
-static int
-parse(char *buf, char **argv) {
-    int argc = 0;
-    while (1) {
-        // find global whitespace
-        while (*buf != '\0' && strchr(WHITESPACE, *buf) != NULL) {
-            *buf ++ = '\0';
-        }
-        if (*buf == '\0') {
-            break;
-        }
-
-        // save and scan past next arg
-        if (argc == MAXARGS - 1) {
-            cprintf("Too many arguments (max %d).\n", MAXARGS);
-        }
-        argv[argc ++] = buf;
-        while (*buf != '\0' && strchr(WHITESPACE, *buf) == NULL) {
-            buf ++;
-        }
-    }
-    return argc;
-}
-
-/* *
- * runcmd - parse the input string, split it into separated arguments
- * and then lookup and invoke some related commands/
- * */
-static int
-runcmd(char *buf, struct trapframe *tf) {
-    char *argv[MAXARGS];
-    int argc = parse(buf, argv);
-    if (argc == 0) {
-        return 0;
-    }
-    int i;
-    for (i = 0; i < NCOMMANDS; i ++) {
-        if (strcmp(commands[i].name, argv[0]) == 0) {
-            return commands[i].func(argc - 1, argv + 1, tf);
-        }
-    }
-    cprintf("Unknown command '%s'\n", argv[0]);
-    return 0;
-}
-
-/***** Implementations of basic kernel monitor commands *****/
-
-void
-monitor(struct trapframe *tf) {
-    cprintf("Welcome to the kernel debug monitor!!\n");
-    cprintf("Type 'help' for a list of commands.\n");
-
-    if (tf != NULL) {
-        print_trapframe(tf);
-    }
-
-    char *buf;
-    while (1) {
-        if ((buf = readline("K> ")) != NULL) {
-            if (runcmd(buf, tf) < 0) {
-                break;
-            }
-        }
-    }
-}
-
-/* mon_help - print the information about mon_* functions */
-int
-mon_help(int argc, char **argv, struct trapframe *tf) {
-    int i;
-    for (i = 0; i < NCOMMANDS; i ++) {
-        cprintf("%s - %s\n", commands[i].name, commands[i].desc);
-    }
-    return 0;
-}
-
-/* *
- * mon_kerninfo - call print_kerninfo in kern/debug/kdebug.c to
- * print the memory occupancy in kernel.
- * */
-int
-mon_kerninfo(int argc, char **argv, struct trapframe *tf) {
-    print_kerninfo();
-    return 0;
-}
-
-/* *
- * mon_backtrace - call print_stackframe in kern/debug/kdebug.c to
- * print a backtrace of the stack.
- * */
-int
-mon_backtrace(int argc, char **argv, struct trapframe *tf) {
-    print_stackframe();
-    return 0;
-}
-

code/lab6/kern/debug/monitor.h

@@ -1,19 +0,0 @@
-#ifndef __KERN_DEBUG_MONITOR_H__
-#define __KERN_DEBUG_MONITOR_H__
-
-#include <trap.h>
-
-void monitor(struct trapframe *tf);
-
-int mon_help(int argc, char **argv, struct trapframe *tf);
-int mon_kerninfo(int argc, char **argv, struct trapframe *tf);
-int mon_backtrace(int argc, char **argv, struct trapframe *tf);
-int mon_continue(int argc, char **argv, struct trapframe *tf);
-int mon_step(int argc, char **argv, struct trapframe *tf);
-int mon_breakpoint(int argc, char **argv, struct trapframe *tf);
-int mon_watchpoint(int argc, char **argv, struct trapframe *tf);
-int mon_delete_dr(int argc, char **argv, struct trapframe *tf);
-int mon_list_dr(int argc, char **argv, struct trapframe *tf);
-
-#endif /* !__KERN_DEBUG_MONITOR_H__ */
-

code/lab6/kern/debug/panic.c

@@ -1,7 +1,7 @@
 #include <defs.h>
 #include <stdio.h>
 #include <intr.h>
-#include <monitor.h>
+#include <kmonitor.h>
 
 static bool is_panic = 0;
 
@@ -27,7 +27,7 @@ __panic(const char *file, int line, const char *fmt, ...) {
 panic_dead:
     intr_disable();
     while (1) {
-        monitor(NULL);
+        kmonitor(NULL);
     }
 }
 

code/lab6/kern/init/init.c

@@ -12,9 +12,10 @@
 #include <ide.h>
 #include <swap.h>
 #include <proc.h>
+#include <kmonitor.h>
 
 int kern_init(void) __attribute__((noreturn));
-
+void grade_backtrace(void);
 static void lab1_switch_test(void);
 
 int

code/lab6/kern/mm/kmalloc.c

@@ -487,7 +487,7 @@ check_slab(void) {
     void *v0, *v1;
 
     size_t nr_free_pages_store = nr_free_pages();
-    size_t slab_allocated_store = slab_allocated();
+    size_t kernel_allocated_store = slab_allocated();
 
     /* slab must be empty now */
     check_slab_empty();
@@ -633,7 +633,7 @@ check_pass:
     check_slab_empty();
     assert(slab_allocated() == 0);
     assert(nr_free_pages_store == nr_free_pages());
-    assert(slab_allocated_store == slab_allocated());
+    assert(kernel_allocated_store == slab_allocated());
 
     cprintf("check_slab() succeeded!\n");
 }

code/lab6/kern/mm/swap.c

@@ -184,7 +184,7 @@ check_swap(void)
      list_entry_t *le = &free_list;
      while ((le = list_next(le)) != &free_list) {
         struct Page *p = le2page(le, page_link);
-        //assert(PageProperty(p));
+        assert(PageProperty(p));
         count ++, total += p->property;
      }
      assert(total == nr_free_pages());
@@ -277,7 +277,7 @@ check_swap(void)
          struct Page *p = le2page(le, page_link);
          count --, total -= p->property;
      }
-         cprintf("count is %d, total is %d\n",count,total);
+     cprintf("count is %d, total is %d\n",count,total);
      //assert(count == 0);
      
      cprintf("check_swap() succeeded!\n");

code/lab6/kern/mm/vmm.c

@@ -460,6 +460,15 @@ do_pgfault(struct mm_struct *mm, uint32_t error_code, uintptr_t addr) {
     *    page_insert ： build the map of phy addr of an Page with the linear addr la
     *    swap_map_swappable ： set the page swappable
     */
+    /*
+     * LAB5 CHALLENGE ( the implmentation Copy on Write)
+		There are 2 situlations when code comes here.
+		  1) *ptep & PTE_P == 1, it means one process try to write a readonly page. 
+		     If the vma includes this addr is writable, then we can set the page writable by rewrite the *ptep.
+		     This method could be used to implement the Copy on Write (COW) thchnology(a fast fork process method).
+		  2) *ptep & PTE_P == 0 & but *ptep!=0, it means this pte is a  swap entry.
+		     We should add the LAB3's results here.
+     */
         if(swap_init_ok) {
             struct Page *page=NULL;
                                     //(1）According to the mm AND addr, try to load the content of right disk page

code/lab6/kern/process/proc.c

@@ -103,6 +103,22 @@ alloc_proc(void) {
      *       uint32_t flags;                             // Process flag
      *       char name[PROC_NAME_LEN + 1];               // Process name
      */
+     //LAB5 YOUR CODE : (update LAB4 steps)
+    /*
+     * below fields(add in LAB5) in proc_struct need to be initialized	
+     *       uint32_t wait_state;                        // waiting state
+     *       struct proc_struct *cptr, *yptr, *optr;     // relations between processes
+	 */
+     //LAB6 YOUR CODE : (update LAB5 steps)
+    /*
+     * below fields(add in LAB6) in proc_struct need to be initialized
+     *     struct run_queue *rq;                       // running queue contains Process
+     *     list_entry_t run_link;                      // the entry linked in run queue
+     *     int time_slice;                             // time slice for occupying the CPU
+     *     skew_heap_entry_t lab6_run_pool;            // FOR LAB6 ONLY: the entry in the run pool
+     *     uint32_t lab6_stride;                       // FOR LAB6 ONLY: the current stride of the process
+     *     uint32_t lab6_priority;                     // FOR LAB6 ONLY: the priority of process, set by lab6_set_priority(uint32_t)
+     */
     }
     return proc;
 }
@@ -389,6 +405,15 @@ do_fork(uint32_t clone_flags, uintptr_t stack, struct trapframe *tf) {
     //    5. insert proc_struct into hash_list && proc_list
     //    6. call wakup_proc to make the new child process RUNNABLE
     //    7. set ret vaule using child proc's pid
+
+	//LAB5 YOUR CODE : (update LAB4 steps)
+   /* Some Functions
+    *    set_links:  set the relation links of process.  ALSO SEE: remove_links:  lean the relation links of process 
+    *    -------------------
+	*    update step 1: set child proc's parent to current process, make sure current process's wait_state is 0
+	*    update step 5: insert proc_struct into hash_list && proc_list, set the relation links of process
+    */
+	
 fork_out:
     return ret;
 
@@ -771,7 +796,7 @@ user_main(void *arg) {
 static int
 init_main(void *arg) {
     size_t nr_free_pages_store = nr_free_pages();
-    size_t slab_allocated_store = kallocated();
+    size_t kernel_allocated_store = kallocated();
 
     int pid = kernel_thread(user_main, NULL, 0);
     if (pid <= 0) {
@@ -788,7 +813,7 @@ init_main(void *arg) {
     assert(list_next(&proc_list) == &(initproc->list_link));
     assert(list_prev(&proc_list) == &(initproc->list_link));
     assert(nr_free_pages_store == nr_free_pages());
-    assert(slab_allocated_store == kallocated());
+    assert(kernel_allocated_store == kallocated());
     cprintf("init check memory pass.\n");
     return 0;
 }

code/lab6/kern/schedule/sched.c

@@ -6,6 +6,7 @@
 #include <assert.h>
 #include <default_sched.h>
 
+// the list of timer
 static list_entry_t timer_list;
 
 static struct sched_class *sched_class;
@@ -48,7 +49,7 @@ sched_init(void) {
     sched_class = &default_sched_class;
 
     rq = &__rq;
-    rq->max_time_slice = 20;
+    rq->max_time_slice = MAX_TIME_SLICE;
     sched_class->init(rq);
 
     cprintf("sched class: %s\n", sched_class->name);
@@ -98,6 +99,7 @@ schedule(void) {
     local_intr_restore(intr_flag);
 }
 
+// add timer to timer_list
 void
 add_timer(timer_t *timer) {
     bool intr_flag;
@@ -120,6 +122,7 @@ add_timer(timer_t *timer) {
     local_intr_restore(intr_flag);
 }
 
+// del timer from timer_list
 void
 del_timer(timer_t *timer) {
     bool intr_flag;
@@ -139,6 +142,7 @@ del_timer(timer_t *timer) {
     local_intr_restore(intr_flag);
 }
 
+// call scheduler to update tick related info, and check the timer is expired? If expired, then wakup proc
 void
 run_timer_list(void) {
     bool intr_flag;

code/lab6/kern/schedule/sched.h

@@ -5,17 +5,20 @@
 #include <list.h>
 #include <skew_heap.h>
 
+#define MAX_TIME_SLICE 20
+
 struct proc_struct;
 
 typedef struct {
-    unsigned int expires;
-    struct proc_struct *proc;
-    list_entry_t timer_link;
+    unsigned int expires;       //the expire time
+    struct proc_struct *proc;   //the proc wait in this timer. If the expire time is end, then this proc will be scheduled
+    list_entry_t timer_link;    //the timer list
 } timer_t;
 
 #define le2timer(le, member)            \
 to_struct((le), timer_t, member)
 
+// init a timer
 static inline timer_t *
 timer_init(timer_t *timer, struct proc_struct *proc, int expires) {
     timer->expires = expires;
@@ -62,9 +65,9 @@ struct run_queue {
 void sched_init(void);
 void wakeup_proc(struct proc_struct *proc);
 void schedule(void);
-void add_timer(timer_t *timer);
-void del_timer(timer_t *timer);
-void run_timer_list(void);
+void add_timer(timer_t *timer);     // add timer to timer_list
+void del_timer(timer_t *timer);     // del timer from timer_list
+void run_timer_list(void);          // call scheduler to update tick related info, and check the timer is expired? If expired, then wakup proc
 
 #endif /* !__KERN_SCHEDULE_SCHED_H__ */
 

code/lab6/kern/syscall/syscall.c

@@ -65,11 +65,11 @@ sys_pgdir(uint32_t arg[]) {
     return 0;
 }
 
-static uint32_t
+static int
 sys_gettime(uint32_t arg[]) {
     return (int)ticks;
 }
-static uint32_t
+static int
 sys_lab6_set_priority(uint32_t arg[])
 {
     uint32_t priority = (uint32_t)arg[0];

code/lab6/kern/trap/trap.c

@@ -211,7 +211,7 @@ trap_dispatch(struct trapframe *tf) {
         break;
     case IRQ_OFFSET + IRQ_TIMER:
 #if 0
-    LAB3 : If some page replacement algorithm need tick to change the priority of pages, 
+    LAB3 : If some page replacement algorithm(such as CLOCK PRA) need tick to change the priority of pages,
     then you can add code here. 
 #endif
         /* LAB1 YOUR CODE : STEP 3 */
@@ -224,7 +224,14 @@ trap_dispatch(struct trapframe *tf) {
         /* you should upate you lab1 code (just add ONE or TWO lines of code):
          *    Every TICK_NUM cycle, you should set current process's current->need_resched = 1
          */
-  
+        /* LAB6 YOUR CODE */
+        /* IMPORTANT FUNCTIONS:
+	     * run_timer_list
+	     *----------------------
+	     * you should update your lab5 code (just add ONE or TWO lines of code):
+         *    Every tick, you should update the system time, iterate the timers, and trigger the timers which are end to call scheduler.
+         *    You can use one funcitons to finish all these things.
+         */
         break;
     case IRQ_OFFSET + IRQ_COM1:
         c = cons_getc();

code/lab6/user/libs/syscall.c

@@ -70,7 +70,7 @@ sys_pgdir(void) {
     return syscall(SYS_pgdir);
 }
 
-size_t
+int
 sys_gettime(void) {
     return syscall(SYS_gettime);
 }

code/lab6/user/libs/syscall.h

@@ -9,6 +9,7 @@ int sys_kill(int pid);
 int sys_getpid(void);
 int sys_putc(int c);
 int sys_pgdir(void);
+int sys_gettime(void);
 /* FOR LAB6 ONLY */
 void sys_lab6_set_priority(uint32_t priority);
 

code/lab7/kern/debug/kdebug.c

@@ -8,7 +8,7 @@
 #include <vmm.h>
 #include <proc.h>
 #include <kdebug.h>
-#include <monitor.h>
+#include <kmonitor.h>
 #include <assert.h>
 
 #define STACKFRAME_DEPTH 20

code/lab7/kern/debug/kmonitor.c

@@ -0,0 +1,132 @@
+#include <stdio.h>
+#include <string.h>
+#include <mmu.h>
+#include <trap.h>
+#include <kmonitor.h>
+#include <kdebug.h>
+
+/* *
+ * Simple command-line kernel monitor useful for controlling the
+ * kernel and exploring the system interactively.
+ * */
+
+struct command {
+    const char *name;
+    const char *desc;
+    // return -1 to force monitor to exit
+    int(*func)(int argc, char **argv, struct trapframe *tf);
+};
+
+static struct command commands[] = {
+    {"help", "Display this list of commands.", mon_help},
+    {"kerninfo", "Display information about the kernel.", mon_kerninfo},
+    {"backtrace", "Print backtrace of stack frame.", mon_backtrace},
+};
+
+/* return if kernel is panic, in kern/debug/panic.c */
+bool is_kernel_panic(void);
+
+#define NCOMMANDS (sizeof(commands)/sizeof(struct command))
+
+/***** Kernel monitor command interpreter *****/
+
+#define MAXARGS         16
+#define WHITESPACE      " \t\n\r"
+
+/* parse - parse the command buffer into whitespace-separated arguments */
+static int
+parse(char *buf, char **argv) {
+    int argc = 0;
+    while (1) {
+        // find global whitespace
+        while (*buf != '\0' && strchr(WHITESPACE, *buf) != NULL) {
+            *buf ++ = '\0';
+        }
+        if (*buf == '\0') {
+            break;
+        }
+
+        // save and scan past next arg
+        if (argc == MAXARGS - 1) {
+            cprintf("Too many arguments (max %d).\n", MAXARGS);
+        }
+        argv[argc ++] = buf;
+        while (*buf != '\0' && strchr(WHITESPACE, *buf) == NULL) {
+            buf ++;
+        }
+    }
+    return argc;
+}
+
+/* *
+ * runcmd - parse the input string, split it into separated arguments
+ * and then lookup and invoke some related commands/
+ * */
+static int
+runcmd(char *buf, struct trapframe *tf) {
+    char *argv[MAXARGS];
+    int argc = parse(buf, argv);
+    if (argc == 0) {
+        return 0;
+    }
+    int i;
+    for (i = 0; i < NCOMMANDS; i ++) {
+        if (strcmp(commands[i].name, argv[0]) == 0) {
+            return commands[i].func(argc - 1, argv + 1, tf);
+        }
+    }
+    cprintf("Unknown command '%s'\n", argv[0]);
+    return 0;
+}
+
+/***** Implementations of basic kernel monitor commands *****/
+
+void
+kmonitor(struct trapframe *tf) {
+    cprintf("Welcome to the kernel debug monitor!!\n");
+    cprintf("Type 'help' for a list of commands.\n");
+
+    if (tf != NULL) {
+        print_trapframe(tf);
+    }
+
+    char *buf;
+    while (1) {
+        if ((buf = readline("K> ")) != NULL) {
+            if (runcmd(buf, tf) < 0) {
+                break;
+            }
+        }
+    }
+}
+
+/* mon_help - print the information about mon_* functions */
+int
+mon_help(int argc, char **argv, struct trapframe *tf) {
+    int i;
+    for (i = 0; i < NCOMMANDS; i ++) {
+        cprintf("%s - %s\n", commands[i].name, commands[i].desc);
+    }
+    return 0;
+}
+
+/* *
+ * mon_kerninfo - call print_kerninfo in kern/debug/kdebug.c to
+ * print the memory occupancy in kernel.
+ * */
+int
+mon_kerninfo(int argc, char **argv, struct trapframe *tf) {
+    print_kerninfo();
+    return 0;
+}
+
+/* *
+ * mon_backtrace - call print_stackframe in kern/debug/kdebug.c to
+ * print a backtrace of the stack.
+ * */
+int
+mon_backtrace(int argc, char **argv, struct trapframe *tf) {
+    print_stackframe();
+    return 0;
+}
+

code/lab7/kern/debug/kmonitor.h

@@ -0,0 +1,19 @@
+#ifndef __KERN_DEBUG_MONITOR_H__
+#define __KERN_DEBUG_MONITOR_H__
+
+#include <trap.h>
+
+void kmonitor(struct trapframe *tf);
+
+int mon_help(int argc, char **argv, struct trapframe *tf);
+int mon_kerninfo(int argc, char **argv, struct trapframe *tf);
+int mon_backtrace(int argc, char **argv, struct trapframe *tf);
+int mon_continue(int argc, char **argv, struct trapframe *tf);
+int mon_step(int argc, char **argv, struct trapframe *tf);
+int mon_breakpoint(int argc, char **argv, struct trapframe *tf);
+int mon_watchpoint(int argc, char **argv, struct trapframe *tf);
+int mon_delete_dr(int argc, char **argv, struct trapframe *tf);
+int mon_list_dr(int argc, char **argv, struct trapframe *tf);
+
+#endif /* !__KERN_DEBUG_MONITOR_H__ */
+

code/lab7/kern/debug/monitor.c

@@ -1,132 +0,0 @@
-#include <stdio.h>
-#include <string.h>
-#include <mmu.h>
-#include <trap.h>
-#include <monitor.h>
-#include <kdebug.h>
-
-/* *
- * Simple command-line kernel monitor useful for controlling the
- * kernel and exploring the system interactively.
- * */
-
-struct command {
-    const char *name;
-    const char *desc;
-    // return -1 to force monitor to exit
-    int(*func)(int argc, char **argv, struct trapframe *tf);
-};
-
-static struct command commands[] = {
-    {"help", "Display this list of commands.", mon_help},
-    {"kerninfo", "Display information about the kernel.", mon_kerninfo},
-    {"backtrace", "Print backtrace of stack frame.", mon_backtrace},
-};
-
-/* return if kernel is panic, in kern/debug/panic.c */
-bool is_kernel_panic(void);
-
-#define NCOMMANDS (sizeof(commands)/sizeof(struct command))
-
-/***** Kernel monitor command interpreter *****/
-
-#define MAXARGS         16
-#define WHITESPACE      " \t\n\r"
-
-/* parse - parse the command buffer into whitespace-separated arguments */
-static int
-parse(char *buf, char **argv) {
-    int argc = 0;
-    while (1) {
-        // find global whitespace
-        while (*buf != '\0' && strchr(WHITESPACE, *buf) != NULL) {
-            *buf ++ = '\0';
-        }
-        if (*buf == '\0') {
-            break;
-        }
-
-        // save and scan past next arg
-        if (argc == MAXARGS - 1) {
-            cprintf("Too many arguments (max %d).\n", MAXARGS);
-        }
-        argv[argc ++] = buf;
-        while (*buf != '\0' && strchr(WHITESPACE, *buf) == NULL) {
-            buf ++;
-        }
-    }
-    return argc;
-}
-
-/* *
- * runcmd - parse the input string, split it into separated arguments
- * and then lookup and invoke some related commands/
- * */
-static int
-runcmd(char *buf, struct trapframe *tf) {
-    char *argv[MAXARGS];
-    int argc = parse(buf, argv);
-    if (argc == 0) {
-        return 0;
-    }
-    int i;
-    for (i = 0; i < NCOMMANDS; i ++) {
-        if (strcmp(commands[i].name, argv[0]) == 0) {
-            return commands[i].func(argc - 1, argv + 1, tf);
-        }
-    }
-    cprintf("Unknown command '%s'\n", argv[0]);
-    return 0;
-}
-
-/***** Implementations of basic kernel monitor commands *****/
-
-void
-monitor(struct trapframe *tf) {
-    cprintf("Welcome to the kernel debug monitor!!\n");
-    cprintf("Type 'help' for a list of commands.\n");
-
-    if (tf != NULL) {
-        print_trapframe(tf);
-    }
-
-    char *buf;
-    while (1) {
-        if ((buf = readline("K> ")) != NULL) {
-            if (runcmd(buf, tf) < 0) {
-                break;
-            }
-        }
-    }
-}
-
-/* mon_help - print the information about mon_* functions */
-int
-mon_help(int argc, char **argv, struct trapframe *tf) {
-    int i;
-    for (i = 0; i < NCOMMANDS; i ++) {
-        cprintf("%s - %s\n", commands[i].name, commands[i].desc);
-    }
-    return 0;
-}
-
-/* *
- * mon_kerninfo - call print_kerninfo in kern/debug/kdebug.c to
- * print the memory occupancy in kernel.
- * */
-int
-mon_kerninfo(int argc, char **argv, struct trapframe *tf) {
-    print_kerninfo();
-    return 0;
-}
-
-/* *
- * mon_backtrace - call print_stackframe in kern/debug/kdebug.c to
- * print a backtrace of the stack.
- * */
-int
-mon_backtrace(int argc, char **argv, struct trapframe *tf) {
-    print_stackframe();
-    return 0;
-}
-

code/lab7/kern/debug/monitor.h

@@ -1,19 +0,0 @@
-#ifndef __KERN_DEBUG_MONITOR_H__
-#define __KERN_DEBUG_MONITOR_H__
-
-#include <trap.h>
-
-void monitor(struct trapframe *tf);
-
-int mon_help(int argc, char **argv, struct trapframe *tf);
-int mon_kerninfo(int argc, char **argv, struct trapframe *tf);
-int mon_backtrace(int argc, char **argv, struct trapframe *tf);
-int mon_continue(int argc, char **argv, struct trapframe *tf);
-int mon_step(int argc, char **argv, struct trapframe *tf);
-int mon_breakpoint(int argc, char **argv, struct trapframe *tf);
-int mon_watchpoint(int argc, char **argv, struct trapframe *tf);
-int mon_delete_dr(int argc, char **argv, struct trapframe *tf);
-int mon_list_dr(int argc, char **argv, struct trapframe *tf);
-
-#endif /* !__KERN_DEBUG_MONITOR_H__ */
-

code/lab7/kern/debug/panic.c

@@ -1,7 +1,7 @@
 #include <defs.h>
 #include <stdio.h>
 #include <intr.h>
-#include <monitor.h>
+#include <kmonitor.h>
 
 static bool is_panic = 0;
 
@@ -27,7 +27,7 @@ __panic(const char *file, int line, const char *fmt, ...) {
 panic_dead:
     intr_disable();
     while (1) {
-        monitor(NULL);
+        kmonitor(NULL);
     }
 }
 

code/lab7/kern/init/init.c

@@ -12,9 +12,10 @@
 #include <ide.h>
 #include <swap.h>
 #include <proc.h>
+#include <kmonitor.h>
 
 int kern_init(void) __attribute__((noreturn));
-
+void grade_backtrace(void);
 static void lab1_switch_test(void);
 
 int

code/lab7/kern/mm/kmalloc.c

@@ -487,7 +487,7 @@ check_slab(void) {
     void *v0, *v1;
 
     size_t nr_free_pages_store = nr_free_pages();
-    size_t slab_allocated_store = slab_allocated();
+    size_t kernel_allocated_store = slab_allocated();
 
     /* slab must be empty now */
     check_slab_empty();
@@ -633,7 +633,7 @@ check_pass:
     check_slab_empty();
     assert(slab_allocated() == 0);
     assert(nr_free_pages_store == nr_free_pages());
-    assert(slab_allocated_store == slab_allocated());
+    assert(kernel_allocated_store == slab_allocated());
 
     cprintf("check_slab() succeeded!\n");
 }

code/lab7/kern/mm/swap.c

@@ -184,7 +184,7 @@ check_swap(void)
      list_entry_t *le = &free_list;
      while ((le = list_next(le)) != &free_list) {
         struct Page *p = le2page(le, page_link);
-        //assert(PageProperty(p));
+        assert(PageProperty(p));
         count ++, total += p->property;
      }
      assert(total == nr_free_pages());
@@ -277,7 +277,7 @@ check_swap(void)
          struct Page *p = le2page(le, page_link);
          count --, total -= p->property;
      }
-         cprintf("count is %d, total is %d\n",count,total);
+     cprintf("count is %d, total is %d\n",count,total);
      //assert(count == 0);
      
      cprintf("check_swap() succeeded!\n");

code/lab7/kern/mm/vmm.c

@@ -460,6 +460,15 @@ do_pgfault(struct mm_struct *mm, uint32_t error_code, uintptr_t addr) {
     *    page_insert ： build the map of phy addr of an Page with the linear addr la
     *    swap_map_swappable ： set the page swappable
     */
+    /*
+     * LAB5 CHALLENGE ( the implmentation Copy on Write)
+		There are 2 situlations when code comes here.
+		  1) *ptep & PTE_P == 1, it means one process try to write a readonly page. 
+		     If the vma includes this addr is writable, then we can set the page writable by rewrite the *ptep.
+		     This method could be used to implement the Copy on Write (COW) thchnology(a fast fork process method).
+		  2) *ptep & PTE_P == 0 & but *ptep!=0, it means this pte is a  swap entry.
+		     We should add the LAB3's results here.
+     */
         if(swap_init_ok) {
             struct Page *page=NULL;
                                     //(1）According to the mm AND addr, try to load the content of right disk page

code/lab7/kern/process/proc.c

@@ -103,6 +103,22 @@ alloc_proc(void) {
      *       uint32_t flags;                             // Process flag
      *       char name[PROC_NAME_LEN + 1];               // Process name
      */
+     //LAB5 YOUR CODE : (update LAB4 steps)
+    /*
+     * below fields(add in LAB5) in proc_struct need to be initialized	
+     *       uint32_t wait_state;                        // waiting state
+     *       struct proc_struct *cptr, *yptr, *optr;     // relations between processes
+	 */
+     //LAB6 YOUR CODE : (update LAB5 steps)
+    /*
+     * below fields(add in LAB6) in proc_struct need to be initialized
+     *     struct run_queue *rq;                       // running queue contains Process
+     *     list_entry_t run_link;                      // the entry linked in run queue
+     *     int time_slice;                             // time slice for occupying the CPU
+     *     skew_heap_entry_t lab6_run_pool;            // FOR LAB6 ONLY: the entry in the run pool
+     *     uint32_t lab6_stride;                       // FOR LAB6 ONLY: the current stride of the process
+     *     uint32_t lab6_priority;                     // FOR LAB6 ONLY: the priority of process, set by lab6_set_priority(uint32_t)
+     */
     }
     return proc;
 }
@@ -389,6 +405,15 @@ do_fork(uint32_t clone_flags, uintptr_t stack, struct trapframe *tf) {
     //    5. insert proc_struct into hash_list && proc_list
     //    6. call wakup_proc to make the new child process RUNNABLE
     //    7. set ret vaule using child proc's pid
+
+	//LAB5 YOUR CODE : (update LAB4 steps)
+   /* Some Functions
+    *    set_links:  set the relation links of process.  ALSO SEE: remove_links:  lean the relation links of process 
+    *    -------------------
+	*    update step 1: set child proc's parent to current process, make sure current process's wait_state is 0
+	*    update step 5: insert proc_struct into hash_list && proc_list, set the relation links of process
+    */
+	
 fork_out:
     return ret;
 
@@ -771,7 +796,7 @@ user_main(void *arg) {
 static int
 init_main(void *arg) {
     size_t nr_free_pages_store = nr_free_pages();
-    size_t slab_allocated_store = kallocated();
+    size_t kernel_allocated_store = kallocated();
 
     int pid = kernel_thread(user_main, NULL, 0);
     if (pid <= 0) {
@@ -790,7 +815,7 @@ init_main(void *arg) {
     assert(list_next(&proc_list) == &(initproc->list_link));
     assert(list_prev(&proc_list) == &(initproc->list_link));
     assert(nr_free_pages_store == nr_free_pages());
-    assert(slab_allocated_store == kallocated());
+    assert(kernel_allocated_store == kallocated());
     cprintf("init check memory pass.\n");
     return 0;
 }

code/lab7/kern/schedule/sched.c

@@ -6,6 +6,7 @@
 #include <assert.h>
 #include <default_sched.h>
 
+// the list of timer
 static list_entry_t timer_list;
 
 static struct sched_class *sched_class;
@@ -98,6 +99,7 @@ schedule(void) {
     local_intr_restore(intr_flag);
 }
 
+// add timer to timer_list
 void
 add_timer(timer_t *timer) {
     bool intr_flag;
@@ -120,6 +122,7 @@ add_timer(timer_t *timer) {
     local_intr_restore(intr_flag);
 }
 
+// del timer from timer_list
 void
 del_timer(timer_t *timer) {
     bool intr_flag;
@@ -139,6 +142,7 @@ del_timer(timer_t *timer) {
     local_intr_restore(intr_flag);
 }
 
+// call scheduler to update tick related info, and check the timer is expired? If expired, then wakup proc
 void
 run_timer_list(void) {
     bool intr_flag;

code/lab7/kern/schedule/sched.h

@@ -5,17 +5,20 @@
 #include <list.h>
 #include <skew_heap.h>
 
+#define MAX_TIME_SLICE 20
+
 struct proc_struct;
 
 typedef struct {
-    unsigned int expires;
-    struct proc_struct *proc;
-    list_entry_t timer_link;
+    unsigned int expires;       //the expire time
+    struct proc_struct *proc;   //the proc wait in this timer. If the expire time is end, then this proc will be scheduled
+    list_entry_t timer_link;    //the timer list
 } timer_t;
 
 #define le2timer(le, member)            \
 to_struct((le), timer_t, member)
 
+// init a timer
 static inline timer_t *
 timer_init(timer_t *timer, struct proc_struct *proc, int expires) {
     timer->expires = expires;
@@ -62,9 +65,9 @@ struct run_queue {
 void sched_init(void);
 void wakeup_proc(struct proc_struct *proc);
 void schedule(void);
-void add_timer(timer_t *timer);
-void del_timer(timer_t *timer);
-void run_timer_list(void);
+void add_timer(timer_t *timer);     // add timer to timer_list
+void del_timer(timer_t *timer);     // del timer from timer_list
+void run_timer_list(void);          // call scheduler to update tick related info, and check the timer is expired? If expired, then wakup proc
 
 #endif /* !__KERN_SCHEDULE_SCHED_H__ */
 

code/lab7/kern/syscall/syscall.c

@@ -65,11 +65,11 @@ sys_pgdir(uint32_t arg[]) {
     return 0;
 }
 
-static uint32_t
+static int
 sys_gettime(uint32_t arg[]) {
     return (int)ticks;
 }
-static uint32_t
+static int
 sys_lab6_set_priority(uint32_t arg[])
 {
     uint32_t priority = (uint32_t)arg[0];

code/lab7/kern/trap/trap.c

@@ -211,7 +211,7 @@ trap_dispatch(struct trapframe *tf) {
         break;
     case IRQ_OFFSET + IRQ_TIMER:
 #if 0
-    LAB3 : If some page replacement algorithm need tick to change the priority of pages, 
+    LAB3 : If some page replacement algorithm(such as CLOCK PRA) need tick to change the priority of pages,
     then you can add code here. 
 #endif
         /* LAB1 YOUR CODE : STEP 3 */
@@ -224,7 +224,14 @@ trap_dispatch(struct trapframe *tf) {
         /* you should upate you lab1 code (just add ONE or TWO lines of code):
          *    Every TICK_NUM cycle, you should set current process's current->need_resched = 1
          */
-  
+        /* LAB6 YOUR CODE */
+        /* IMPORTANT FUNCTIONS:
+	     * run_timer_list
+	     *----------------------
+	     * you should update your lab5 code (just add ONE or TWO lines of code):
+         *    Every tick, you should update the system time, iterate the timers, and trigger the timers which are end to call scheduler.
+         *    You can use one funcitons to finish all these things.
+         */
         break;
     case IRQ_OFFSET + IRQ_COM1:
         c = cons_getc();

code/lab7/user/forktree.c

@@ -3,7 +3,7 @@
 #include <string.h>
 
 #define DEPTH 4
-#define SLEEP_TIME 400
+
 void forktree(const char *cur);
 
 void
@@ -31,8 +31,6 @@ forktree(const char *cur) {
 
 int
 main(void) {
-    cprintf("forktree process will sleep %d ticks\n",SLEEP_TIME);
-    sleep(SLEEP_TIME);
     forktree("");
     return 0;
 }

code/lab7/user/libs/syscall.c

@@ -70,7 +70,7 @@ sys_pgdir(void) {
     return syscall(SYS_pgdir);
 }
 
-size_t
+int
 sys_gettime(void) {
     return syscall(SYS_gettime);
 }

code/lab7/user/libs/syscall.h

@@ -9,6 +9,7 @@ int sys_kill(int pid);
 int sys_getpid(void);
 int sys_putc(int c);
 int sys_pgdir(void);
+int sys_gettime(void);
 /* FOR LAB6 ONLY */
 void sys_lab6_set_priority(uint32_t priority);
 

code/lab7/user/spin.c

@@ -3,7 +3,7 @@
 
 int
 main(void) {
-    int pid, ret, i ,j;
+    int pid, ret;
     cprintf("I am the parent. Forking the child...\n");
     pid = fork();
     if (pid== 0) {

code/lab8/kern/debug/kdebug.c

@@ -8,7 +8,7 @@
 #include <vmm.h>
 #include <proc.h>
 #include <kdebug.h>
-#include <monitor.h>
+#include <kmonitor.h>
 #include <assert.h>
 
 #define STACKFRAME_DEPTH 20

code/lab8/kern/debug/kmonitor.c

@@ -0,0 +1,132 @@
+#include <stdio.h>
+#include <string.h>
+#include <mmu.h>
+#include <trap.h>
+#include <kmonitor.h>
+#include <kdebug.h>
+
+/* *
+ * Simple command-line kernel monitor useful for controlling the
+ * kernel and exploring the system interactively.
+ * */
+
+struct command {
+    const char *name;
+    const char *desc;
+    // return -1 to force monitor to exit
+    int(*func)(int argc, char **argv, struct trapframe *tf);
+};
+
+static struct command commands[] = {
+    {"help", "Display this list of commands.", mon_help},
+    {"kerninfo", "Display information about the kernel.", mon_kerninfo},
+    {"backtrace", "Print backtrace of stack frame.", mon_backtrace},
+};
+
+/* return if kernel is panic, in kern/debug/panic.c */
+bool is_kernel_panic(void);
+
+#define NCOMMANDS (sizeof(commands)/sizeof(struct command))
+
+/***** Kernel monitor command interpreter *****/
+
+#define MAXARGS         16
+#define WHITESPACE      " \t\n\r"
+
+/* parse - parse the command buffer into whitespace-separated arguments */
+static int
+parse(char *buf, char **argv) {
+    int argc = 0;
+    while (1) {
+        // find global whitespace
+        while (*buf != '\0' && strchr(WHITESPACE, *buf) != NULL) {
+            *buf ++ = '\0';
+        }
+        if (*buf == '\0') {
+            break;
+        }
+
+        // save and scan past next arg
+        if (argc == MAXARGS - 1) {
+            cprintf("Too many arguments (max %d).\n", MAXARGS);
+        }
+        argv[argc ++] = buf;
+        while (*buf != '\0' && strchr(WHITESPACE, *buf) == NULL) {
+            buf ++;
+        }
+    }
+    return argc;
+}
+
+/* *
+ * runcmd - parse the input string, split it into separated arguments
+ * and then lookup and invoke some related commands/
+ * */
+static int
+runcmd(char *buf, struct trapframe *tf) {
+    char *argv[MAXARGS];
+    int argc = parse(buf, argv);
+    if (argc == 0) {
+        return 0;
+    }
+    int i;
+    for (i = 0; i < NCOMMANDS; i ++) {
+        if (strcmp(commands[i].name, argv[0]) == 0) {
+            return commands[i].func(argc - 1, argv + 1, tf);
+        }
+    }
+    cprintf("Unknown command '%s'\n", argv[0]);
+    return 0;
+}
+
+/***** Implementations of basic kernel monitor commands *****/
+
+void
+kmonitor(struct trapframe *tf) {
+    cprintf("Welcome to the kernel debug monitor!!\n");
+    cprintf("Type 'help' for a list of commands.\n");
+
+    if (tf != NULL) {
+        print_trapframe(tf);
+    }
+
+    char *buf;
+    while (1) {
+        if ((buf = readline("K> ")) != NULL) {
+            if (runcmd(buf, tf) < 0) {
+                break;
+            }
+        }
+    }
+}
+
+/* mon_help - print the information about mon_* functions */
+int
+mon_help(int argc, char **argv, struct trapframe *tf) {
+    int i;
+    for (i = 0; i < NCOMMANDS; i ++) {
+        cprintf("%s - %s\n", commands[i].name, commands[i].desc);
+    }
+    return 0;
+}
+
+/* *
+ * mon_kerninfo - call print_kerninfo in kern/debug/kdebug.c to
+ * print the memory occupancy in kernel.
+ * */
+int
+mon_kerninfo(int argc, char **argv, struct trapframe *tf) {
+    print_kerninfo();
+    return 0;
+}
+
+/* *
+ * mon_backtrace - call print_stackframe in kern/debug/kdebug.c to
+ * print a backtrace of the stack.
+ * */
+int
+mon_backtrace(int argc, char **argv, struct trapframe *tf) {
+    print_stackframe();
+    return 0;
+}
+

code/lab8/kern/debug/kmonitor.h

@@ -0,0 +1,19 @@
+#ifndef __KERN_DEBUG_MONITOR_H__
+#define __KERN_DEBUG_MONITOR_H__
+
+#include <trap.h>
+
+void kmonitor(struct trapframe *tf);
+
+int mon_help(int argc, char **argv, struct trapframe *tf);
+int mon_kerninfo(int argc, char **argv, struct trapframe *tf);
+int mon_backtrace(int argc, char **argv, struct trapframe *tf);
+int mon_continue(int argc, char **argv, struct trapframe *tf);
+int mon_step(int argc, char **argv, struct trapframe *tf);
+int mon_breakpoint(int argc, char **argv, struct trapframe *tf);
+int mon_watchpoint(int argc, char **argv, struct trapframe *tf);
+int mon_delete_dr(int argc, char **argv, struct trapframe *tf);
+int mon_list_dr(int argc, char **argv, struct trapframe *tf);
+
+#endif /* !__KERN_DEBUG_MONITOR_H__ */
+

code/lab8/kern/debug/monitor.c

@@ -1,132 +0,0 @@
-#include <stdio.h>
-#include <string.h>
-#include <mmu.h>
-#include <trap.h>
-#include <monitor.h>
-#include <kdebug.h>
-
-/* *
- * Simple command-line kernel monitor useful for controlling the
- * kernel and exploring the system interactively.
- * */
-
-struct command {
-    const char *name;
-    const char *desc;
-    // return -1 to force monitor to exit
-    int(*func)(int argc, char **argv, struct trapframe *tf);
-};
-
-static struct command commands[] = {
-    {"help", "Display this list of commands.", mon_help},
-    {"kerninfo", "Display information about the kernel.", mon_kerninfo},
-    {"backtrace", "Print backtrace of stack frame.", mon_backtrace},
-};
-
-/* return if kernel is panic, in kern/debug/panic.c */
-bool is_kernel_panic(void);
-
-#define NCOMMANDS (sizeof(commands)/sizeof(struct command))
-
-/***** Kernel monitor command interpreter *****/
-
-#define MAXARGS         16
-#define WHITESPACE      " \t\n\r"
-
-/* parse - parse the command buffer into whitespace-separated arguments */
-static int
-parse(char *buf, char **argv) {
-    int argc = 0;
-    while (1) {
-        // find global whitespace
-        while (*buf != '\0' && strchr(WHITESPACE, *buf) != NULL) {
-            *buf ++ = '\0';
-        }
-        if (*buf == '\0') {
-            break;
-        }
-
-        // save and scan past next arg
-        if (argc == MAXARGS - 1) {
-            cprintf("Too many arguments (max %d).\n", MAXARGS);
-        }
-        argv[argc ++] = buf;
-        while (*buf != '\0' && strchr(WHITESPACE, *buf) == NULL) {
-            buf ++;
-        }
-    }
-    return argc;
-}
-
-/* *
- * runcmd - parse the input string, split it into separated arguments
- * and then lookup and invoke some related commands/
- * */
-static int
-runcmd(char *buf, struct trapframe *tf) {
-    char *argv[MAXARGS];
-    int argc = parse(buf, argv);
-    if (argc == 0) {
-        return 0;
-    }
-    int i;
-    for (i = 0; i < NCOMMANDS; i ++) {
-        if (strcmp(commands[i].name, argv[0]) == 0) {
-            return commands[i].func(argc - 1, argv + 1, tf);
-        }
-    }
-    cprintf("Unknown command '%s'\n", argv[0]);
-    return 0;
-}
-
-/***** Implementations of basic kernel monitor commands *****/
-
-void
-monitor(struct trapframe *tf) {
-    cprintf("Welcome to the kernel debug monitor!!\n");
-    cprintf("Type 'help' for a list of commands.\n");
-
-    if (tf != NULL) {
-        print_trapframe(tf);
-    }
-
-    char *buf;
-    while (1) {
-        if ((buf = readline("K> ")) != NULL) {
-            if (runcmd(buf, tf) < 0) {
-                break;
-            }
-        }
-    }
-}
-
-/* mon_help - print the information about mon_* functions */
-int
-mon_help(int argc, char **argv, struct trapframe *tf) {
-    int i;
-    for (i = 0; i < NCOMMANDS; i ++) {
-        cprintf("%s - %s\n", commands[i].name, commands[i].desc);
-    }
-    return 0;
-}
-
-/* *
- * mon_kerninfo - call print_kerninfo in kern/debug/kdebug.c to
- * print the memory occupancy in kernel.
- * */
-int
-mon_kerninfo(int argc, char **argv, struct trapframe *tf) {
-    print_kerninfo();
-    return 0;
-}
-
-/* *
- * mon_backtrace - call print_stackframe in kern/debug/kdebug.c to
- * print a backtrace of the stack.
- * */
-int
-mon_backtrace(int argc, char **argv, struct trapframe *tf) {
-    print_stackframe();
-    return 0;
-}
-

code/lab8/kern/debug/monitor.h

@@ -1,19 +0,0 @@
-#ifndef __KERN_DEBUG_MONITOR_H__
-#define __KERN_DEBUG_MONITOR_H__
-
-#include <trap.h>
-
-void monitor(struct trapframe *tf);
-
-int mon_help(int argc, char **argv, struct trapframe *tf);
-int mon_kerninfo(int argc, char **argv, struct trapframe *tf);
-int mon_backtrace(int argc, char **argv, struct trapframe *tf);
-int mon_continue(int argc, char **argv, struct trapframe *tf);
-int mon_step(int argc, char **argv, struct trapframe *tf);
-int mon_breakpoint(int argc, char **argv, struct trapframe *tf);
-int mon_watchpoint(int argc, char **argv, struct trapframe *tf);
-int mon_delete_dr(int argc, char **argv, struct trapframe *tf);
-int mon_list_dr(int argc, char **argv, struct trapframe *tf);
-
-#endif /* !__KERN_DEBUG_MONITOR_H__ */
-

code/lab8/kern/debug/panic.c

@@ -1,7 +1,7 @@
 #include <defs.h>
 #include <stdio.h>
 #include <intr.h>
-#include <monitor.h>
+#include <kmonitor.h>
 
 static bool is_panic = 0;
 
@@ -27,7 +27,7 @@ __panic(const char *file, int line, const char *fmt, ...) {
 panic_dead:
     intr_disable();
     while (1) {
-        monitor(NULL);
+        kmonitor(NULL);
     }
 }
 

code/lab8/kern/fs/fs.c

@@ -78,7 +78,7 @@ files_closeall(struct files_struct *filesp) {
 }
 
 int
-dup_fs(struct files_struct *to, struct files_struct *from) {
+dup_files(struct files_struct *to, struct files_struct *from) {
 //    cprintf("[dup_fs]\n");
     assert(to != NULL && from != NULL);
     assert(files_count(to) == 0 && files_count(from) > 0);