hobbielektronika
Synchronize two tasks by the help of event signals. Watch the output in a Terminal window!
Revision 0:6c4ab9386095, committed 2016-02-23
- Comitter:
- icserny
- Date:
- Tue Feb 23 13:27:53 2016 +0000
- Commit message:
- First version
Changed in this revision
diff -r 000000000000 -r 6c4ab9386095 main.cpp
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp Tue Feb 23 13:27:53 2016 +0000
@@ -0,0 +1,57 @@
+/** 10_rtos_signals
+ *
+ * Synchronize two tasks by the help of event signals.
+ * Thread2 changes the state of LED1 when any event flag arrives.
+ * Thread1 (the main thread) sends event flags at reguar intervals.
+ * You may experimenting by changeing this program:
+ * - Wait for a given flag: for example Thread::signal_wait(0x8);
+ * - Wait for multiple events: for example Thread::signal_wait(0x5);
+ * - Wait for a nonexistent events: for example Thread::signal_wait(0x10000);
+ * - Wait for a limited time: for example Thread::signal_wait(0x3,500);
+ *
+ * Watch the output in a Terminal window!
+ */
+
+#include "mbed.h"
+#include "rtos.h"
+
+DigitalOut led(LED1);
+
+void led_thread(void const *argument)
+{
+ while (true) {
+ // Signal flags that are reported as event are automatically cleared.
+ osEvent evt = Thread::signal_wait(0); //Wait for any signal
+ switch(evt.status) {
+ case osOK:
+ printf("osOK\n"); //no error or event occurred
+ break;
+ case osEventSignal:
+ printf("osEventSignal = %#05x\n",evt.value.signals); //signal event occurred
+ break;
+ case osEventTimeout:
+ printf("osEventTimeout\n"); //timeout occurred
+ break;
+ case osErrorValue:
+ printf("osErrorValue\n");
+ break; //value of a parameter is out of range.
+ default:
+ printf("Unknown error flag: %#08x\n",(uint32_t)evt.status);
+ break;
+ };
+ led = !led;
+ }
+}
+
+int main (void)
+{
+ int32_t signal_mask = 0x1;
+ Thread thread2(led_thread);
+
+ while (true) {
+ Thread::wait(1000);
+ thread2.signal_set(signal_mask); //send signals from 0x0001 to 0x8000
+ signal_mask <<=1; //switch to next signal
+ if(signal_mask > 0x8000) signal_mask=0x1;
+ }
+}
diff -r 000000000000 -r 6c4ab9386095 mbed-rtos.lib --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/mbed-rtos.lib Tue Feb 23 13:27:53 2016 +0000 @@ -0,0 +1,1 @@ +http://mbed.org/users/mbed_official/code/mbed-rtos/#07314541bd12
diff -r 000000000000 -r 6c4ab9386095 mbed.bld --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/mbed.bld Tue Feb 23 13:27:53 2016 +0000 @@ -0,0 +1,1 @@ +http://mbed.org/users/mbed_official/code/mbed/builds/252557024ec3 \ No newline at end of file