Jaydeep Shah / Mbed OS 11) SEMAPHORE_PART2

SEMAPHORE PART 2, FUNCTION : try_acquire() use and replacement of wait() function JAYDEEP SHAH--radhey04ec@gmil.com

main.cpp@0:ee291bda0e6e, 2020-07-12 (annotated)

Committer:
radhey04ec
Date:
Sun Jul 12 09:41:04 2020 +0000
Revision:
0:ee291bda0e6e
SEMAPHORE PART 2 COMMITED; try_acquire() FUNCTION USE; ; JAYDEEP SHAH -- radhey04ec@gmail.com

Who changed what in which revision?

UserRevisionLine numberNew contents of line
radhey04ec 0:ee291bda0e6e 1 //SEMAPHORE PART 2
radhey04ec 0:ee291bda0e6e 2
radhey04ec 0:ee291bda0e6e 3 //INSTEAD OF wait() -- > use try_acquire() = return bool = true if acquire
radhey04ec 0:ee291bda0e6e 4 //NEW FUNCTION INTRO IN MBED
radhey04ec 0:ee291bda0e6e 5
radhey04ec 0:ee291bda0e6e 6 //USE SERIAL TERMINAL WITH 9600 BAUD RATE 8-N-1 FORMAT
radhey04ec 0:ee291bda0e6e 7
radhey04ec 0:ee291bda0e6e 8 //Created by : JAYDEEP SHAH --radhey04ec@gmail.com
radhey04ec 0:ee291bda0e6e 9
radhey04ec 0:ee291bda0e6e 10
radhey04ec 0:ee291bda0e6e 11 //Library Added :::::
radhey04ec 0:ee291bda0e6e 12 #include "mbed.h"
radhey04ec 0:ee291bda0e6e 13
radhey04ec 0:ee291bda0e6e 14 DigitalOut led(LED1); // ON BOARD LED
radhey04ec 0:ee291bda0e6e 15 InterruptIn btn(USER_BUTTON); // ON BOARD BUTTON PORT PC_13
radhey04ec 0:ee291bda0e6e 16 //INTERRUPT REGISTERATION
radhey04ec 0:ee291bda0e6e 17
radhey04ec 0:ee291bda0e6e 18 Semaphore updates(0); //SEMAPHORE OBJECT CREATE = SHARE RESOURCE 0
radhey04ec 0:ee291bda0e6e 19 //NO SHARE RESOURCE ONLY ISR
radhey04ec 0:ee291bda0e6e 20
radhey04ec 0:ee291bda0e6e 21 void do_something() { //ISR FUNCTION
radhey04ec 0:ee291bda0e6e 22 // release the semaphore
radhey04ec 0:ee291bda0e6e 23 updates.release(); // NOW V=1
radhey04ec 0:ee291bda0e6e 24 }
radhey04ec 0:ee291bda0e6e 25
radhey04ec 0:ee291bda0e6e 26 int main() {
radhey04ec 0:ee291bda0e6e 27 btn.fall(&do_something);
radhey04ec 0:ee291bda0e6e 28
radhey04ec 0:ee291bda0e6e 29 while (1) {
radhey04ec 0:ee291bda0e6e 30 // wait for the semaphore to be released from the ISR
radhey04ec 0:ee291bda0e6e 31 bool v = updates.try_acquire(); //RETURN STORE IN V
radhey04ec 0:ee291bda0e6e 32
radhey04ec 0:ee291bda0e6e 33 // now this runs on the main thread, and is safe
radhey04ec 0:ee291bda0e6e 34 if(v == 1)
radhey04ec 0:ee291bda0e6e 35
radhey04ec 0:ee291bda0e6e 36 {
radhey04ec 0:ee291bda0e6e 37 led = !led; //LED TOGGLE
radhey04ec 0:ee291bda0e6e 38 printf("Toggle LED!\r\n"); //SERIAL PRINT
radhey04ec 0:ee291bda0e6e 39 }
radhey04ec 0:ee291bda0e6e 40 }
radhey04ec 0:ee291bda0e6e 41 }