Add ao_wake_task and ao_exit

ao_wake_task signals a specific task to wake up.
ao_exit terminates the current task.

Signed-off-by: Keith Packard <keithp@keithp.com>

2 files changed, 29 insertions, 1 deletions

diff --git a/src/ao.h b/src/ao.h
index b6862a87..13271109 100644
--- a/src/ao.h
+++ b/src/ao.h
@@ -63,6 +63,10 @@ ao_sleep(__xdata void *wchan);
 void
 ao_wakeup(__xdata void *wchan);
 
+/* Wake up a specific task */
+void
+ao_wake_task(__xdata struct ao_task *task);
+
 /* Yield the processor to another task */
 void
 ao_yield(void) _naked;
@@ -71,6 +75,10 @@ ao_yield(void) _naked;
 void
 ao_add_task(__xdata struct ao_task * task, void (*start)(void), __code char *name) __reentrant;
 
+/* Terminate the current task */
+void
+ao_exit(void);
+
 /* Dump task info to console */
 void
 ao_task_info(void);
diff --git a/src/ao_task.c b/src/ao_task.c
index 12b73943..136444b0 100644
--- a/src/ao_task.c
+++ b/src/ao_task.c
@@ -93,7 +93,9 @@ ao_yield(void) _naked
 		push	_bp
 	_endasm;
 
-	if (ao_cur_task_index != AO_NO_TASK_INDEX)
+	if (ao_cur_task_index == AO_NO_TASK_INDEX)
+		ao_cur_task_index = ao_num_tasks-1;
+	else
 	{
 		uint8_t stack_len;
 		__data uint8_t *stack_ptr;
@@ -199,6 +201,24 @@ ao_wakeup(__xdata void *wchan)
 }
 
 void
+ao_wake_task(__xdata struct ao_task *task)
+{
+	task->wchan = NULL;
+}
+
+void
+ao_exit(void)
+{
+	uint8_t	i;
+	ao_num_tasks--;
+	for (i = ao_cur_task_index; i < ao_num_tasks; i++)
+		ao_tasks[i] = ao_tasks[i+1];
+	ao_cur_task_index = AO_NO_TASK_INDEX;
+	ao_yield();
+	/* we'll never get back here */
+}
+
+void
 ao_task_info(void)
 {
 	uint8_t	i;