# GSoC: Linked List || Blog post by Chetan Karwa || #6 **URL:** \ **Category:** GSoC-2021\ **Created:** [July 9, 2021, 10:10pm UTC](https://fortran-lang.discourse.group/t/gsoc-linked-list-blog-post-by-chetan-karwa-6/1534 "2021-07-09T22:10:20Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![Chetan\_Karwa](https://avatars.discourse-cdn.com/v4/letter/c/e99b99/32.png) [@Chetan\_Karwa](https://fortran-lang.discourse.group/u/Chetan_Karwa)\ **Post date:** [July 9, 2021, 10:10pm UTC](https://fortran-lang.discourse.group/t/gsoc-linked-list-blog-post-by-chetan-karwa-6/1534/1 "2021-07-09T22:10:21Z")
Greetings Everyone, Progress in the past week: - Implemented pop() and remove() functionality. - I also have some results regarding parallel deletion linked list(list of list implementation) 1.First of all, I was using cpu\_time regarding which Arjen mentioned that it returns the sum of computation time taken by each thread. 2.So a better fit for this was to use wall clock time. (system\_clock) 3.Though the test results still didn’t match our expectations and the computation time actually increased instead of decreasing. 4.Arjen had a possible reason for this abrupt outcome 5.A detailed note on what was the test program and the output received can be found [here](https://github.com/ChetanKarwa/Fortran-Linked-List/tree/Parallel-Computing/List_of_list/Parallel_Computing_Results). - > One explanation for this: the OS’s memory management gets in the way. It may or may not be threaded itself, or it needs to take a lot of care to ensure things remain consistent. That would be a valuable lesson: calculations benefit from multithreading, but data structures much less. Well, that may be cutting corners a bit, but that would be my conclusion. - For now, we have decided to drop the plan of parallel computing because: 1.The outputs are not desired 2.We discussed the use of parallel computing in stdlib and how does that affect a user in general. (Maybe the user can use stdlib in some program that is already working on parallel threads so he might run into the complexity of nested parallel programs) - In addition to all these, thanks to @themos to let me know of the compilations errors that he faced in the NAG compiler which were overlooked in gfortran compiler. I will fix all such possible errors. For some personal reasons, I couldn’t achieve my goals for the past week. So I intend to finish them and also set extra tasks for this week. Plan for the coming week: - Implement insert() API. - Open an issue on Fortran-Lang stdlib. - Make a report of testing the list\_of\_list module to hold a million or more strings of 20 to 1000 characters. - Fix the compilation errors (NAG). Thank you ---
**Author:** ![ivanpribec](https://yyz2.discourse-cdn.com/free1/user_avatar/fortran-lang.discourse.group/ivanpribec/32/3290_2.png) [@ivanpribec](https://fortran-lang.discourse.group/u/ivanpribec)\ **Post date:** [July 13, 2021, 1:00pm UTC](https://fortran-lang.discourse.group/t/gsoc-linked-list-blog-post-by-chetan-karwa-6/1534/2 "2021-07-13T13:00:43Z")
Hello Chetan, it is nice to observe your progress. Browsing through the ACM Fortran Forum today I noticed there are some articles that might be of interest to you: > Meissner, L. P. (1997, August). Fortran 90 & 95 linked list operations: managing an ordered list with pointers to pointers. In _ACM SIGPLAN Fortran Forum_ (Vol. 16, No. 2, pp. 18-22). New York, NY, USA: ACM. [Fortran 90 & 95 linked list operations: managing an ordered list with pointers to pointers: ACM SIGPLAN Fortran Forum: Vol 16, No 2](https://doi.org/10.1145/270891.270892) > Blevins, J. R. (2009, December). A generic linked list implementation in Fortran 95. In _ACM SIGPLAN Fortran Forum_ (Vol. 28, No. 3, pp. 2-7). New York, NY, USA: ACM. [https://doi.org/10.1145/1667140.1667141](https://doi.org/10.1145/1667140.1667141) The website [fortran.com](https://www.fortran.com/) previously owned by Walt Brainerd used to offer a book: > Loren P. Meissner (1998). Fortran 90 & 95 Array and Pointer Techniques: Objects, Data Structures, and Algorithms. I’ve seen some copies published on the internet in clear violation of the original copyright agreement.