Portal ==>> AutoSAR Practical series 300 speak 「 candy Autosar」 General catalogue

1 Event mechanism

As shown in the figure below , In embedded systems , Usually you need a synchronization mechanism , That is, a task is waiting for a specific event to happen ; If the event is ready , Synchronization signal sent by another task , Or send it to a task through an interrupt handler , That is, input from peripheral devices .

Events are proprietary signals assigned to any extended task . Multiple events can be assigned to the same task . A task may wait for one or more events , So as to enter the waiting state . Any task （ Basic or extended ） You can set events for any task . If the receiving task has been waiting for at least one of these events , This will cause the receiving task to enter the ready state .
There are the following precautions ：

1. Extended tasks can support event waiting mechanism , If there is a waiting point , The task will be blocked , You must wait for the event to occur before continuing

2. The event can come from other tasks or from the interrupt service program Isr.<