3bcdee89c6
This commit fixes support for tickless implementations that call vTaskStepTick() with the maximum number of allowed ticks to step. vTaskStepTick() --------------- Function vTaskStepTick() provides a way for the tickless idle implementation to account for ticks that elapse during tickless idle. The maximum number of stepped ticks allowed is the number passed to portSUPPRESS_TICKS_AND_SLEEP(). It is the number of ticks between xTickCount and xNextTaskUnblockTime. vTaskStepTick() is specifically intended for use with tickless idle, so it always executes with the scheduler disabled. For reference, compare it with the more general function xTaskCatchUpTicks(). Without this Change ------------------- Prior to this commit, if a task is supposed to wake at xTickCount == 0xFFFFFFFF, then when tickless idle ends, function vTaskStepTick() sets the tick to 0xFFFFFFFF but the task remains on the delayed list because xTaskIncrementTick() does not execute. One tick later, xTaskIncrementTick() executes because it's time to increment xTickCount to 0x00000000. An assertion failure occurs in taskSWITCH_DELAYED_LISTS() because the delayed task list is not empty. Other examples of valling vTaskStepTick() with the maximum allowed number of ticks merely result in a task waking one tick late. Default Tickless Implementations -------------------------------- Note that the default tickless implementations never pass the maximum allowed value to vTaskStepTick(). The default implementations use the tick interrupt to finish the sleep and allow that one tick to be counted normally via the tick ISR and xTaskIncrementTick(). |
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| .github | ||
| include | ||
| portable | ||
| CONTRIBUTING.md | ||
| croutine.c | ||
| event_groups.c | ||
| GitHub-FreeRTOS-Kernel-Home.url | ||
| History.txt | ||
| LICENSE.md | ||
| list.c | ||
| queue.c | ||
| Quick_Start_Guide.url | ||
| README.md | ||
| SECURITY.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.