Diff: main.cpp

Revision:

0:a59680ccdb41

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Sun Jan 29 20:42:21 2017 +0000
@@ -0,0 +1,80 @@
+/**
+ * @brief first thread control program with  MBED OS
+ */
+#include "mbed.h"
+#include "rtos.h"
+
+/* declares threads for this demo: */
+const size_t a_stk_size = 1024;
+uint8_t a_stk[a_stk_size];
+Thread a_thread(osPriorityHigh, a_stk_size, &a_stk[0]);
+
+const size_t b_stk_size = 1024;
+uint8_t b_stk[b_stk_size];
+Thread b_thread(osPriorityNormal, b_stk_size, &b_stk[0]);
+
+/* Demo how to declare a semaphore */
+Semaphore sema;
+
+
+/* reserve the debbuger uart to shell interface */
+Serial pc_serial(USBTX,USBRX);
+
+
+/**
+ * @brief thread a function 
+ */
+static void thread_a(void)
+{
+    pc_serial.printf("## started thread_a execution! ##\n\r");
+ 
+    for(;;) {
+
+        /* adds dummy processing */
+        for(int i = 0 ; i < 0xFFFFFF; i++);
+ 
+        pc_serial.printf("## thread_a will take the semaphore! ##\n\r");        
+        //a_thread.yield();
+        
+        /* once executed, gives thread_a to do so, and sync the two tasks */
+        sema.wait(osWaitForever);
+        pc_serial.printf("## thread_a took the semaphore! ##\n\r");
+
+    }
+}
+
+
+/**
+ * @brief thread a function 
+ */
+static void thread_b(void)
+{
+    pc_serial.printf("## started thread_b execution! ##\n\r");
+ 
+    for(;;) {
+        
+        /* adds dummy processing */
+        for(int i = 0 ; i < 0xFFFFFF; i++);
+        
+        pc_serial.printf("## thread_b will signal the semaphore! ##\n\r");
+        
+        //b_thread.yield();
+        
+        /* release the semaphore and allow the high priority task to run */
+        sema.release();
+        pc_serial.printf("## thread_b signaled the semaphore, but thread_a consumed it! ##\n\r"); 
+    }
+}
+
+
+
+/**
+ * @brief main application loop
+ */
+int main(void) 
+{  
+    pc_serial.baud(115200);
+    a_thread.start(thread_a);
+    b_thread.start(thread_b);
+    return 0;
+}
\ No newline at end of file