Mutex

Description

• Functions as a typical mutex.
• If the shared resource is not available, the requesting thread is put into a blocked state.
• Conforms to the IMutex interface to work with the CircularQueue and DataPayload.

Firmware Component Library

Library API Docs

Source Code

Info

This is a common data structure. You can find plenty of information online, such as Shawn Hymel's Introduction to RTOS - Mutex.

Warning

Note that CMSIS-RTOS V2 wrapper class implementation must be created after calling osKernelInitalize(). For this reason, this implementation has a separate Create() method.

Example

Creating a mutex.

#include "../DFR_Libraries/Application/Mutex/mutex_cmsisv2.hpp"

const osMutexAttr_t mutex_attributes = {
    "myThreadMutex",
    osMutexRecursive | osMutexPrioInherit,
    NULL,
    0U
};

auto m = std::make_shared<application::MutexCmsisV2>(mutex_attributes);


int main() {
    osKernelInitialize();
    m->Create();

    // Request to use resource shared with other thread
    m->Lock();

    // ...
    // Use the shared resource

    // Release the shared resource for other threads to use
    m->Unlock();

    return 0;
}

For more examples, the firmware currently uses two mutexes to share the CircularQueue and DataPayload among multiple threads.