becbb89181
Add a cap to the queue locks cRxLock and cTxLock members of the queue data structure count the number items received and sent to the queue while the queue was locked. These are later used to unblock tasks waiting on the queue when the queue is unlocked. The data type of these members is int8_t and this can trigger overflow check assert if an ISR continuously reads/writes to the queue in a loop as reported in this issue: https://github.com/FreeRTOS/FreeRTOS-Kernel/issues/419. Note due to the length of the operation is it not recommended to write to the queue that many times from an ISR - stream buffers are a better option, or alternatively, defer the operation to a task by just having the ISR send a direct to task notification to unblock the task. This PR caps the values of the cRxLock and cTxLock to the number of tasks in the system because we cannot unblocks more tasks than there are in the system. Note that the same assert could still be triggered is the application creates more than 127 tasks. Signed-off-by: Gaurav Aggarwal <aggarg@amazon.com> |
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|---|---|---|
| .github | ||
| include | ||
| portable | ||
| .gitmodules | ||
| croutine.c | ||
| event_groups.c | ||
| GitHub-FreeRTOS-Kernel-Home.url | ||
| History.txt | ||
| LICENSE.md | ||
| list.c | ||
| queue.c | ||
| Quick_Start_Guide.url | ||
| README.md | ||
| stream_buffer.c | ||
| tasks.c | ||
| timers.c | ||
Getting started
This repository contains FreeRTOS kernel source/header files and kernel ports only. This repository is referenced as a submodule in FreeRTOS/FreeRTOS repository, which contains pre-configured demo application projects under FreeRTOS/Demo directory.
The easiest way to use FreeRTOS is to start with one of the pre-configured demo application projects. That way you will have the correct FreeRTOS source files included, and the correct include paths configured. Once a demo application is building and executing you can remove the demo application files, and start to add in your own application source files. See the FreeRTOS Kernel Quick Start Guide for detailed instructions and other useful links.
Additionally, for FreeRTOS kernel feature information refer to the Developer Documentation, and API Reference.
Getting help
If you have any questions or need assistance troubleshooting your FreeRTOS project, we have an active community that can help on the FreeRTOS Community Support Forum.
Cloning this repository
To clone using HTTPS:
git clone https://github.com/FreeRTOS/FreeRTOS-Kernel.git
Using SSH:
git clone git@github.com:FreeRTOS/FreeRTOS-Kernel.git
Repository structure
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The root of this repository contains the three files that are common to every port - list.c, queue.c and tasks.c. The kernel is contained within these three files. croutine.c implements the optional co-routine functionality - which is normally only used on very memory limited systems.
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The
./portabledirectory contains the files that are specific to a particular microcontroller and/or compiler. See the readme file in the./portabledirectory for more information. -
The
./includedirectory contains the real time kernel header files.
Code Formatting
FreeRTOS files are formatted using the "uncrustify" tool. The configuration file used by uncrustify can be found in the FreeRTOS/FreeRTOS repository.
Spelling
lexicon.txt contains words that are not traditionally found in an English dictionary. It is used by the spellchecker to verify the various jargon, variable names, and other odd words used in the FreeRTOS code base. If your pull request fails to pass the spelling and you believe this is a mistake, then add the word to lexicon.txt. Note that only the FreeRTOS Kernel source files are checked for proper spelling, the portable section is ignored.