Skip to content

Critical Section doc update #298

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

Merged
merged 7 commits into from
Oct 30, 2017
Merged

Critical Section doc update #298

Changes from 5 commits
Commits
Show all changes
7 commits
Select commit Hold shift + click to select a range
d1c1ade
Critical Section doc update
Oct 20, 2017
38c98e9
Copy edit CriticalSectionLock.md
Oct 20, 2017
655c655
Changed example repo
Oct 23, 2017
807375e
Make minor capitalization change
Oct 23, 2017
8bead55
Added RAII approach and scope description
Oct 25, 2017
72310c3
Copy edit CriticalSectionLock.md
Oct 30, 2017
6ac407f
Change passive to active voice
Oct 30, 2017
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
15 changes: 15 additions & 0 deletions docs/reference/api/platform/CriticalSectionLock.md
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,3 +1,18 @@
## CriticalSectionLock

CriticalSectionLock class provides a mechanism to access a resource without interruption. With the `lock` API, you can enter critical section with interrupts disabled. The `unlock` API is the exit from critical section, and the state of interrupts is restored upon exit. Nesting of critical section is supported, and interrupts are enabled only when we exit from last nested critical section.
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Do you want to remove mentions the lock and unlock since these aren't RAII and may be deprecated?

Copy link
Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I will keep them in 5.6 version as they are relevant. Hopefully we would deprecate by 5.7

Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Sounds good


CriticalSectionLock class is based on RAII approach i.e. lock is acquired in constructor and destroyed automatically when out of scope as part of destructor. Usage of CriticalSectionLock as global or member of class is not recommended, as you will enter critical section on object creation and all interrupts will be disabled.


<span class="notes">**Note:** You must not use time consuming operations, standard library and RTOS functions inside critical section.</span>

## CriticalSectionLock class reference

[![View code](https://www.mbed.com/embed/?type=library)](https://os.mbed.com/docs/v5.6/mbed-os-api-doxy/classmbed_1_1_critical_section_lock.html)

## CriticalSectionLock example

Here is an example that demonstrates a race condition issue and how CriticalSectionLock helps resolves it.

[![View code](https://www.mbed.com/embed/?url=https://os.mbed.com/teams/mbed_example/code/mbed-os-example-critical-section/)](https://os.mbed.com/teams/mbed_example/code/mbed-os-example-critical-section/file/a88acbffd78b/main.cpp)