Thanks to visit codestin.com
Credit goes to github.com

Skip to content

Update Question 7 #1

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
wants to merge 1 commit into
base: master
Choose a base branch
from
Open

Update Question 7 #1

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 1 addition & 1 deletion concurrency/32_concurrency_bugs/answers.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -44,7 +44,7 @@ These figures don't exactly match my predictions, but they aren't too far off. L

###### 7. Now let’s study `vector-try-wait.c`. First make sure you understand the code. Is the first call to `pthread_mutex_trylock()` really needed? Now run the code. How fast does it run compared to the global order approach? How does the number of retries, as counted by the code, change as the number of threads increases?

The first call is really needed, how else are you going to lock the destination vector?
No, we don’t need the first trylock, and using is a really wrong way of implementing trylock because the threads will never sleep and will waste the CPU time in waiting only we should use just `pthread_mutex_lock()`.

Below are run times with the options `-t -l 100000 -d`, varying the number of threads (`-n`):

Expand Down