| commit | f2081af03066a41cc218435a3c61d4ed90c87c77 | [log] [tgz] |
|---|---|---|
| author | RichardBarry <3073890+RichardBarry@users.noreply.github.com> | Wed May 27 12:28:48 2020 -0700 |
| committer | GitHub <noreply@github.com> | Wed May 27 12:28:48 2020 -0700 |
| tree | bd67026f1c00738e71100d661de189d27880220a | |
| parent | e4e4fb01a19fa9bff3bec4b398c860aa92110c2e [diff] |
Feature/multiple direct to task notifications (#63) Description Before this change each task had a single direct to task notification value and state as described here: https://www.FreeRTOS.org/RTOS-task-notifications.html. After this change each task has an array of task notifications, so more than one task notification value and state per task. The new FreeRTOSConfig.h compile time constant configTASK_NOTIFICATION_ARRAY_ENTRIES sets the number of indexes in the array. Each notification within the array operates independently - a task can only block on one notification within the array at a time and will not be unblocked by a notification sent to any other array index. Task notifications were introduced as a light weight method for peripheral drivers to pass data and events to tasks without the need for an intermediary object such as a semaphore - for example, to unblock a task from an ISR when the operation of a peripheral completed. That use case only requires a single notification value. Their popularity and resultant expanded use cases have since made the single value a limitation - especially as FreeRTOS stream and message buffers themselves use the notification mechanism. This change resolves that limitation. Stream and message buffers still use the task notification at array index 0, but now application writers can avoid any conflict that might have with their own use of task notifications by using notifications at array indexes other than 0. The pre-existing task notification API functions work in a backward compatible way by always using the task notification at array index 0. For each such function there is now an equivalent that is postfixed "Indexed" and takes an additional parameter to specify which index within the array it should operate upon. For example, xTaskNotify() is the original that only operates on array index 0. xTaskNotifyIndexed() is the new function that can operate on any array index. Test Steps The update is tested using the Win32 demo (PR to be created in the FreeRTOS/FreeRTOS github repo), which has been updated to build and run a new test file FreeRTOS/Demo/Common/Minimal/TaskNotifyArray.c. The tests in that file are in addition to, not a replacement for those in FreeRTOS/Demo/Common/Minimal/TaskNotify.c. By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.
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.
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.
To clone using HTTPS:
git clone https://github.com/FreeRTOS/FreeRTOS-Kernel.git
Using SSH:
git clone git@github.com:FreeRTOS/FreeRTOS-Kernel.git
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.
The ./portable directory contains the files that are specific to a particular microcontroller and/or compiler. See the readme file in the ./portable directory for more information.
The ./include directory contains the real time kernel header files.