mbed_example / Mbed OS rtos_isr

isr example

main.cpp@7:985db97e8ae0, 2018-10-15 (annotated)

Committer:
bridadan
Date:
Mon Oct 15 17:26:47 2018 -0500
Revision:
7:985db97e8ae0
Parent:
4:40078e697304 
Updating example to show usage of the idle thread. Also showing Thread and Handler modes.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
emilmont 1:3043ec651794 1 #include "mbed.h"
mbed_official 0:4979ad0f5cb9 2
bridadan 7:985db97e8ae0 3 Ticker ticker;
mab5449 4:40078e697304 4 Thread thread;
bridadan 7:985db97e8ae0 5 Queue<const char*, 5> trail;
bridadan 7:985db97e8ae0 6
bridadan 7:985db97e8ae0 7 // Since we're printing from multiple threads, we need a mutex
bridadan 7:985db97e8ae0 8 Mutex print_lock;
bridadan 7:985db97e8ae0 9
bridadan 7:985db97e8ae0 10 enum ExecutionTypes {
bridadan 7:985db97e8ae0 11 IDLE,
bridadan 7:985db97e8ae0 12 USER,
bridadan 7:985db97e8ae0 13 ISR
bridadan 7:985db97e8ae0 14 };
emilmont 1:3043ec651794 15
bridadan 7:985db97e8ae0 16 const char* ExecutionMessages[] = {
bridadan 7:985db97e8ae0 17 "the idle thread",
bridadan 7:985db97e8ae0 18 "a user thread",
bridadan 7:985db97e8ae0 19 "interrupt context"
bridadan 7:985db97e8ae0 20 };
emilmont 1:3043ec651794 21
bridadan 7:985db97e8ae0 22 void handler() {
bridadan 7:985db97e8ae0 23 // Check to see if we're in interrupt context
bridadan 7:985db97e8ae0 24 if (core_util_is_isr_active()) {
bridadan 7:985db97e8ae0 25 // Do not print since we're in interrupt context
bridadan 7:985db97e8ae0 26 trail.put(&(ExecutionMessages[ISR]));
bridadan 7:985db97e8ae0 27 } else {
bridadan 7:985db97e8ae0 28 // Safe to print since we're in a user thread
bridadan 7:985db97e8ae0 29 print_lock.lock();
bridadan 7:985db97e8ae0 30 printf("Starting user thread\r\n");
bridadan 7:985db97e8ae0 31 print_lock.unlock();
bridadan 7:985db97e8ae0 32 while(true) {
bridadan 7:985db97e8ae0 33 trail.put(&(ExecutionMessages[USER]));
bridadan 7:985db97e8ae0 34 wait(5);
bridadan 7:985db97e8ae0 35 }
emilmont 1:3043ec651794 36 }
emilmont 1:3043ec651794 37 }
emilmont 1:3043ec651794 38
bridadan 7:985db97e8ae0 39 void custom_idle_function() {
bridadan 7:985db97e8ae0 40 // Custom idle behavior would go here
bridadan 7:985db97e8ae0 41 // We won't print here since the default idle thread's stack is too small
bridadan 7:985db97e8ae0 42 trail.put(&(ExecutionMessages[IDLE]));
bridadan 7:985db97e8ae0 43
bridadan 7:985db97e8ae0 44 // Switch back to the default idle behavior
bridadan 7:985db97e8ae0 45 Kernel::attach_idle_hook(NULL);
bridadan 7:985db97e8ae0 46 }
mab5449 4:40078e697304 47
bridadan 7:985db97e8ae0 48 int main() {
bridadan 7:985db97e8ae0 49 printf("Starting execution example\r\n");
bridadan 7:985db97e8ae0 50
bridadan 7:985db97e8ae0 51 // Attach the custom idle thread function
bridadan 7:985db97e8ae0 52 Kernel::attach_idle_hook(custom_idle_function);
bridadan 7:985db97e8ae0 53
bridadan 7:985db97e8ae0 54 // Trigger the interrupt every 3 seconds
bridadan 7:985db97e8ae0 55 ticker.attach(handler, 3);
bridadan 7:985db97e8ae0 56
bridadan 7:985db97e8ae0 57 // Start the user thread
bridadan 7:985db97e8ae0 58 thread.start(handler);
bridadan 7:985db97e8ae0 59
bridadan 7:985db97e8ae0 60 // Get the past exectuion trail
emilmont 1:3043ec651794 61 while (true) {
bridadan 7:985db97e8ae0 62 osEvent evt = trail.get();
emilmont 1:3043ec651794 63 if (evt.status != osEventMessage) {
bridadan 7:985db97e8ae0 64 print_lock.lock();
bridadan 7:985db97e8ae0 65 printf("Failed to retrieve the execution trail (returned %02x)\r\n", evt.status);
bridadan 7:985db97e8ae0 66 print_lock.unlock();
emilmont 1:3043ec651794 67 } else {
bridadan 7:985db97e8ae0 68 print_lock.lock();
bridadan 7:985db97e8ae0 69 printf("Execution was in %s\r\n", *(const char**)evt.value.v);
bridadan 7:985db97e8ae0 70 print_lock.unlock();
emilmont 1:3043ec651794 71 }
emilmont 1:3043ec651794 72 }
emilmont 1:3043ec651794 73 }