libtf: stackable timeouts

instead of having per-function argument, use a push/pop mechanism:
- multiple timers inside fiber use only one heap entry
- easy to chain multiple possibly blocking operations inside one
  timeout block

1 files changed, 37 insertions, 18 deletions

diff --git a/include/libtf/fiber.h b/include/libtf/fiber.h
index c3d87c6..ce3745b 100644
--- a/include/libtf/fiber.h
+++ b/include/libtf/fiber.h
@@ -19,27 +19,22 @@
 #include <libtf/list.h>
 #include <libtf/heap.h>
 
-#define TF_UCTX_H "uctx-setjmp.h"
-
 /* Fiber wakeup reasons */
 #define TF_WAKEUP_NONE		0
 #define TF_WAKEUP_IMMEDIATE	-EAGAIN
 #define TF_WAKEUP_KILL		-EINTR
-#define TF_WAKEUP_TIMEOUT	-ETIMEDOUT
+#define TF_WAKEUP_TIMEOUT	-ETIME
+#define TF_WAKEUP_THIS_TIMEOUT	-ETIMEDOUT
 #define TF_WAKEUP_FD		-EIO
 
-/* Special timeouts for tf_schedule() */
-#define TF_NO_TIMEOUT			-1
-#define TF_NO_TIMEOUT_CHANGE		-2
+struct tf_poll_data {
+	int			epoll_fd;
+	int			num_waiters;
+};
 
 /* Scheduler */
 struct tf_fiber;
 
-struct tf_poll_data {
-	int epoll_fd;
-	int num_waiters;
-};
-
 struct tf_scheduler {
 	struct tf_list_head	run_q;
 	struct tf_heap_head	heap;
@@ -47,7 +42,6 @@ struct tf_scheduler {
 	int			num_fibers;
 	tf_mtime_t		scheduler_time;
 	struct tf_poll_data	poll_data;
-
 };
 
 struct tf_main_ctx {
@@ -55,6 +49,11 @@ struct tf_main_ctx {
 	char **			argv;
 };
 
+struct tf_timeout {
+	tf_mtime_t	saved_timeout;
+	unsigned int	timeout_change;
+};
+
 static inline
 struct tf_scheduler *tf_get_scheduler(void)
 {
@@ -86,18 +85,38 @@ void *tf_fiber_create(tf_fiber_proc fiber_main, int private_size);
 void *tf_fiber_get(void *data);
 void tf_fiber_put(void *data);
 
-/* Scheduling and fiber management */
-void tf_exit(void) attribute_noreturn;
-void tf_kill(void *fiber);
+#define tf_timed(func, timeout)						\
+	({								\
+		struct tf_timeout __timeout;				\
+		tf_timeout_push(&__timeout, timeout);			\
+		tf_timeout_pop(&__timeout, (func));			\
+	})
+
+//* Scheduling and fiber management */
+void tf_timeout_push(struct tf_timeout *timeout, tf_mtime_diff_t milliseconds);
+int __tf_timeout_pop(struct tf_timeout *timeout, int err);
+
+static inline int tf_timeout_pop(struct tf_timeout *timeout, int err)
+{
+	if (unlikely(timeout->timeout_change))
+		return __tf_timeout_pop(timeout, err);
+	return err;
+}
 
-int  tf_schedule(int milliseconds);
+int  tf_schedule(void);
 void tf_wakeup(struct tf_fiber *fiber, int wakeup_type);
+void tf_exit(void) attribute_noreturn;
+void tf_kill(void *fiber);
 int  tf_yield(void);
 
 static inline
-int tf_msleep(int milliseconds)
+int tf_msleep(tf_mtime_diff_t milliseconds)
 {
-	return tf_schedule(milliseconds);
+	int r;
+	r = tf_timed(tf_schedule(), milliseconds);
+	if (r == TF_WAKEUP_THIS_TIMEOUT)
+		r = 0;
+	return r;
 }
 
 #endif