Replace the RTOS with a simple cooperative tasker.

There are no priorities and no preemption, so tasks run in a round-robin
fashion, and explicitly yield control.

1 files changed, 68 insertions, 0 deletions

diff --git a/task.h b/task.h
new file mode 100644
index 0000000..ee0dc61
--- /dev/null
+++ b/task.h
@@ -0,0 +1,68 @@
+/*
+ * task.c
+ * ----------------
+ * Simple cooperative tasking system.
+ *
+ * Copyright (c) 2017, NORDUnet A/S All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ * - Redistributions of source code must retain the above copyright notice,
+ *   this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ *
+ * - Neither the name of the NORDUnet nor the names of its contributors may
+ *   be used to endorse or promote products derived from this software
+ *   without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+ * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+ * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+ * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef _TASK_H_
+#define _TASK_H_
+
+#include <sys/types.h>
+
+typedef enum task_state {
+    TASK_INIT,
+    TASK_WAITING,
+    TASK_READY
+} task_state_t;
+
+typedef struct task_cb tcb_t;
+
+typedef void (*funcp_t)(void);
+
+extern tcb_t *task_add(char *name, funcp_t func, void *cookie, void *stack, size_t stack_len);
+
+extern void task_yield(void);
+extern void task_sleep(void);
+extern void task_wake(tcb_t *t);
+
+extern tcb_t *task_get_tcb(void);
+extern char *task_get_name(tcb_t *t);
+extern funcp_t task_get_func(tcb_t *t);
+extern void *task_get_cookie(tcb_t *t);
+extern task_state_t task_get_state(tcb_t *t);
+extern void *task_get_stack(tcb_t *t);
+extern size_t task_get_stack_highwater(tcb_t *t);
+
+extern tcb_t *task_iterate(tcb_t *t);
+
+extern void task_set_idle_hook(funcp_t func);
+
+#endif /* _TASK_H_ */