Method for managing a plurality of tasks by a multicore motor vehicle processor
Disclosed is a method for managing a plurality of tasks of a one-off function implemented by a motor vehicle computer, the computer including a microcontroller, the microcontroller, termed a “multicore” microcontroller, including a plurality of cores, each of which is capable of processing regular functions and one-off functions, each one-off function including a plurality of tasks to be executed, each of which is identified by an identifier, the method including, during the processing of the tasks of a one-off function, each time a core of the plurality of cores is available to process a task, a step of the available core selecting, from a predetermined ordered list of identifiers of the tasks of the one-off function, the identifier of the first task which has not yet been processed by the other cores, and a step of the available core processing the task that corresponds to the selected identifier.
1. A method for managing a plurality of tasks of a one-off function implemented by a motor vehicle computer including a multicore microcontroller including a plurality of cores, each of the cores being configured to process a plurality of regular functions and a plurality of one-off functions, each of the one-off functions including a plurality f a tasks to be executed in predetermined task order, each of the plurality of tasks being identified by an identifier, said method comprising, during processing of the tasks of a one-off function of the plurality of one-off functions:
detecting a one-off event requiring implementation of the one-off function during execution of the regular functions by the plurality of cores;
putting on hold the execution of the regular functions by the plurality of cores after detecting the one-off event;
executing, by each core of the plurality of cores, a common management task that is configured to run through a predetermined ordered list of identifiers of the tasks of the one-off function and select the identifier of a first unprocessed task, which has not yet been processed by the other cores, from unprocessed tasks in the predetermined task order, each time a core of the plurality of cores becomes available to process a task, after detecting the one-off event and putting on hold the execution of the regular functions;
processing, by the available core, the task that corresponds to the selected identifier; and
when all of the tasks of the one-off function are finished being executed by the plurality of cores, restarting the execution of the regular functions by the plurality of cores,
wherein the identifier of the first unprocessed task is selected by the available core after the available core has completed processing one of the tasks from a plurality of tasks being processed of the predetermined task order while at least one of the other cores is concurrently processing another task that has started processing of the tasks being processed in the predetermined task order other than the first unprocessed task.
2. The method as claimed in claim 1 , wherein the common management function uses a binary variable for each of the tasks to indicate a state of handling of said respective task by one of the cores.
3. The method as claimed in claim 2 , wherein the common management function uses an atomic function to manage updating the binary variable associated with each of the tasks.
4. The method as claimed in claim 3 , further comprising initializing the binary variables prior to execution of the one-off function.
5. The method as claimed in claim 2 , further comprising initializing the binary variables prior to execution of the one-off function.
6. The method as claimed in claim 1 , wherein, when the available core selects the identifier of the first unprocessed task, an indicator associated with the identifier of the first unprocessed task is changed, and when the other cores examine the changed indicator, the other cores move to a next unprocessed task of the unprocessed tasks in the predetermined task order.
7. A computer for a motor vehicle, said computer comprising:
a multicore microcontroller including a plurality of cores, each of the cores being configured to process a plurality of regular functions and a of one-off functions, each of the one-off functions including a plurality of tasks to be executed in a predetermined task order, each of the plurality of tasks being identified by an identifier, the multicore microcontroller being configured to
detect a one-off event requiring implementation of the one-off function during execution of the regular functions by the plurality of cores,
put on hold the execution of the regular functions by the plurality of cores after detecting the one-off event,
execute, by each core of the plurality of cores, a common management task that is configured to run through a predetermined ordered list of identifiers of the tasks of the one-off function and select the identifier of a first unprocessed task, which has not yet been processed by the other cores, from unprocessed tasks in the predetermined task order, each time a core of the plurality of cores becomes available to process a task, after detecting the one-off event and putting on hold the execution of the regular functions,
process, by the available core, said task that corresponds to the selected identifier, and
when all of the tasks of the one-off function are finished being executed by the plurality of cores, restart the execution of the regular functions by the plurality of cores,
wherein the identifier of the first unprocessed task is selected by the available core after the available core has completed processing one of the tasks from a plurality of tasks being processed of the predetermined task order while at least one of the other cores is concurrently processing another task that has started processing of the tasks being processed in the predetermined task order other than the first unprocessed task.
8. A motor vehicle comprising the computer as claimed in claim 7 .