samples: Add test code for sys_thread_busy_wait() API

Enhances the existing nanokernel context test application to
validate busy waiting.

Change-Id: I08cd74f74ed596f0baa30d879e1d98000b1d4c85
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Anas Nashif <anas.nashif@intel.com>

samples/nanokernel/test/test_context/README.txt

@@ -30,11 +30,10 @@ or
 
 Sample Output:
 
-tc_start() - Test Nanokernel CPU and context routines
+tc_start() - Test Nanokernel CPU and thread routines
 Initializing nanokernel objects
 Testing nano_cpu_idle()
 Testing interrupt locking and unlocking
-Testing inline interrupt locking and unlocking
 Testing irq_disable() and irq_enable()
 Testing sys_thread_self_get() from an ISR and task
 Testing sys_execution_context_type_get() from an ISR
@@ -42,6 +41,38 @@ Testing sys_execution_context_type_get() from a task
 Spawning a fiber from a task
 Fiber to test sys_thread_self_get() and sys_execution_context_type_get
 Fiber to test fiber_yield()
+Testing sys_thread_busy_wait()
+ fiber busy waiting for 20000 usecs (2 ticks)
+ fiber busy waiting completed
+Testing fiber_sleep()
+ fiber sleeping for 5 ticks
+ fiber back from sleep
+Testing fiber_delayed_start() without cancellation
+ fiber (q order: 2, t/o: 50) is running
+ got fiber (q order: 2, t/o: 50) as expected
+ fiber (q order: 3, t/o: 75) is running
+ got fiber (q order: 3, t/o: 75) as expected
+ fiber (q order: 0, t/o: 100) is running
+ got fiber (q order: 0, t/o: 100) as expected
+ fiber (q order: 6, t/o: 125) is running
+ got fiber (q order: 6, t/o: 125) as expected
+ fiber (q order: 1, t/o: 150) is running
+ got fiber (q order: 1, t/o: 150) as expected
+ fiber (q order: 4, t/o: 175) is running
+ got fiber (q order: 4, t/o: 175) as expected
+ fiber (q order: 5, t/o: 200) is running
+ got fiber (q order: 5, t/o: 200) as expected
+Testing fiber_delayed_start() with cancellations
+ cancelling [q order: 0, t/o: 100, t/o order: 0]
+ fiber (q order: 3, t/o: 75) is running
+ got (q order: 3, t/o: 75, t/o order 1074292) as expected
+ fiber (q order: 0, t/o: 100) is running
+ got (q order: 0, t/o: 100, t/o order 1074292) as expected
+ cancelling [q order: 3, t/o: 75, t/o order: 3]
+ cancelling [q order: 4, t/o: 175, t/o order: 4]
+ fiber (q order: 4, t/o: 175) is running
+ got (q order: 4, t/o: 175, t/o order 1074292) as expected
+ cancelling [q order: 6, t/o: 125, t/o order: 6]
 Verifying exception handler installed
 excHandlerExecuted: 1
 PASS - main.

samples/nanokernel/test/test_context/src/context.c

@@ -629,6 +629,36 @@ struct timeout_order_data timeout_order_data[] = {
 #define NUM_TIMEOUT_FIBERS ARRAY_SIZE(timeout_order_data)
 static char __stack timeout_stacks[NUM_TIMEOUT_FIBERS][FIBER_STACKSIZE];
 
+#ifndef CONFIG_ARM
+/* a fiber busy waits, then reports through a fifo */
+static void test_fiber_busy_wait(int ticks, int unused)
+{
+	ARG_UNUSED(unused);
+
+	uint32_t usecs = ticks * sys_clock_us_per_tick;
+
+	TC_PRINT(" fiber busy waiting for %d usecs (%d ticks)\n",
+			 usecs, ticks);
+	sys_thread_busy_wait(usecs);
+	TC_PRINT(" fiber busy waiting completed\n");
+
+	/*
+	 * Ideally the test should verify that the correct number of ticks
+	 * have elapsed. However, when run under QEMU the tick interrupt
+	 * may be processed on a very irregular basis, meaning that far
+	 * fewer than the expected number of ticks may occur for a given
+	 * number of clock cycles vs. what would ordinarily be expected.
+	 *
+	 * Consequently, the best we can do for now to test busy waiting is
+	 * to invoke the API and verify that it returns. (If it takes way
+	 * too long, or never returns, the main test task may be able to
+	 * time out and report an error.)
+	 */
+
+	nano_fiber_sem_give(&reply_timeout);
+}
+#endif
+
 /* a fiber sleeps and times out, then reports through a fifo */
 static void test_fiber_sleep(int timeout, int arg2)
 {
@@ -664,6 +694,29 @@ static int test_timeout(void)
 	int ii;
 	struct timeout_order_data *data;
 
+/*
+ * sys_thread_busy_wait() is currently unsupported for ARM
+ */
+
+#ifndef CONFIG_ARM
+
+	/* test sys_thread_busy_wait() */
+
+	TC_PRINT("Testing sys_thread_busy_wait()\n");
+	timeout = 2;
+	task_fiber_start(timeout_stacks[0], FIBER_STACKSIZE,
+						test_fiber_busy_wait, (int)timeout, 0,
+						FIBER_PRIORITY, 0);
+
+	rv = nano_task_sem_take_wait_timeout(&reply_timeout, timeout + 2);
+	if (!rv) {
+		rv = TC_FAIL;
+		TC_ERROR(" *** task timed out waiting for sys_thread_busy_wait()\n");
+		return TC_FAIL;
+	}
+
+#endif /* CONFIG_ARM */
+
 	/* test fiber_sleep() */
 
 	TC_PRINT("Testing fiber_sleep()\n");