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Posted by burry94 on May 25, 2017

Hi! We would like to modify the value of the system variable pxMutexHolder defined in the file task.c, how can we access its value through a function? We tried to change its value from our main() but it didn't work since pxMutexHoder cannot be accessed by our application.


Posted by rtel on May 25, 2017

I don't think pxMutexHolder is a system variable defined inside tasks.c. The function xTaskPriorityInherit() has a parameter called pxMutexHolder - is that what you mean? That parameter is local to the function xTaskPriorityInherit() so can't be changed. The mutex holder value is actually stored inside a queue structure, which is defined in queue.c, not a task control block. You could potentially change the value stored in the queue itself, that could be done using the traceBLOCKINGONQUEUE_RECEIVE() macro which gets executed (if defined) immediately before xTaskPriorityInherit() is called.

This is very detailed and messy though, and don't expect anything to work after you have modified it.

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