The project is implemented using FreeRTOS on the target emulation board provided via Eclipse CDT Embedded.
-
There are two sender tasks. Each sender task sleeps for a RANDOM period of time Tsender and when it wakes up it sends a message to the queue containing the string “Time is XYZ” where XYZ is current time in system ticks. If the queue is full, the sending operation fails and a counter counting total number of blocked messages is incremented. Upon successful sending, a counter counting total number of transmitted messages is incremented.
-
The receiver task sleeps for another FIXED period of time Treceiver and then wakes up and checks for any received message in the queue. If there is a message in the queue, it reads it, increments total number of received messages and sleeps again. If there is no message it sleeps again immediately. Note that receiver reads one message at a time even if there are more than one message in the queue.
-
The sleep/wake control of the three tasks is performed via three timers one for each task. The callback function for each timer is specified as follows:
-
Sender Timer Callback Function: When called it releases a dedicated semaphore on which the sender task is waiting/blocked on. The sender task is then unblocked and can send to the queue.
-
Receiver Timer Callback Function: When called it releases a dedicated semaphore on which the receiver task is waiting/blocked on. The receiver task is then unblocked and performs a read on the queue as described above. When the receiver receives 500 messages, the receiver timer callback function calls the “Reset” function that performs the following:
1- Print the total number of successfully sent messages and the total number of blocked messages.
2- Reset t h e total number of successfully sent messages, t h e total number of blocked messages
and received message.
3- Clears the queue.
4- Configure the values controlling the sender timer period Tsender to the next values in two arrays
specifying the lower and upper bound values of the uniformly distributed timer period. The first array
holds the values {50, 80, 110, 140, 170, 200} and the second holds the values {150, 200, 250, 300,
350, 400} expressing in msec the timer lower and upper bounds for a uniform distribution.
If all values in the array are used, destroy the timers and print a message “Game Over”and stop execution.
