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

2 files changed, 71 insertions, 37 deletions

diff --git a/src/fiber.c b/src/fiber.c
index b678842..3f8bb15 100644
--- a/src/fiber.c
+++ b/src/fiber.c
@@ -16,15 +16,20 @@
 #include <libtf/fiber.h>
 #include <libtf/io.h>
 
+#define TF_TIMEOUT_CHANGE_NEEDED			1
+#define TF_TIMEOUT_CHANGE_NEW_VALUE			2
+
 struct tf_fiber {
 	unsigned int		ref_count;
 	int			wakeup_type;
+	unsigned int		timeout_change;
+	tf_mtime_t		timeout;
 	struct tf_list_node	queue_node;
 	struct tf_heap_node	heap_node;
 	char			data[TF_EMPTY_ARRAY];
 };
 
-#include TF_UCTX_H
+#include "uctx-setjmp.h"
 
 /* FIXME: should be in thread local storage */
 struct tf_scheduler *__tf_scheduler;
@@ -108,6 +113,8 @@ static void process_heap(struct tf_scheduler *sched)
 	       tf_mtime_diff(now, tf_heap_get_value(&sched->heap)) >= 0) {
 		node = tf_heap_get_node(&sched->heap);
 		f = container_of(node, struct tf_fiber, heap_node);
+		if (f->wakeup_type == TF_WAKEUP_NONE)
+			f->wakeup_type = TF_WAKEUP_TIMEOUT;
 		run_fiber(sched, f);
 	}
 }
@@ -170,18 +177,58 @@ int tf_main_args(tf_fiber_proc main_fiber, int argc, char **argv)
 	return 0;
 }
 
-int tf_schedule(tf_mtime_diff_t milliseconds)
+void tf_timeout_push(struct tf_timeout *timeout, tf_mtime_diff_t milliseconds)
+{
+	struct tf_fiber *f = tf_get_fiber();
+	tf_mtime_t abs = tf_mtime() + milliseconds;
+	int active;
+
+	if (f->timeout_change)
+		active = (f->timeout_change & TF_TIMEOUT_CHANGE_NEW_VALUE);
+	else
+		active = tf_heap_node_active(&f->heap_node);
+
+	if (!active || tf_mtime_diff(abs, f->timeout) < 0) {
+		/* Save previous timeout */
+		timeout->saved_timeout = f->timeout;
+		timeout->timeout_change = TF_TIMEOUT_CHANGE_NEEDED;
+		if (active)
+			timeout->timeout_change |= TF_TIMEOUT_CHANGE_NEW_VALUE;
+
+		/* Make new timeout pending */
+		f->timeout = abs;
+		f->timeout_change = TF_TIMEOUT_CHANGE_NEEDED
+				  | TF_TIMEOUT_CHANGE_NEW_VALUE;
+	} else {
+		timeout->timeout_change = 0;
+	}
+}
+
+int __tf_timeout_pop(struct tf_timeout *timeout, int err)
+{
+	struct tf_fiber *f = tf_get_fiber();
+
+	f->timeout = timeout->saved_timeout;
+	f->timeout_change = timeout->timeout_change;
+	if (err == TF_WAKEUP_TIMEOUT)
+		err = TF_WAKEUP_THIS_TIMEOUT;
+	return err;
+}
+
+int tf_schedule(void)
 {
 	struct tf_scheduler *sched = tf_get_scheduler();
 	struct tf_fiber *schedf = container_of((void*) sched, struct tf_fiber, data);
 	struct tf_fiber *f = sched->active_fiber;
 
+	if (unlikely(f->timeout_change)) {
+		if (f->timeout_change & TF_TIMEOUT_CHANGE_NEW_VALUE)
+			tf_heap_change(&f->heap_node, &sched->heap, f->timeout);
+		else
+			tf_heap_delete(&f->heap_node, &sched->heap);
+		f->timeout_change = 0;
+	}
 	f->wakeup_type = TF_WAKEUP_NONE;
-	if (milliseconds == TF_NO_TIMEOUT)
-		tf_heap_delete(&f->heap_node, &sched->heap);
-	else if (milliseconds != TF_NO_TIMEOUT_CHANGE)
-		tf_heap_change(&f->heap_node, &sched->heap,
-			       tf_mtime() + milliseconds);
 
 	return tf_uctx_transfer(f, schedf, TF_WAKEUP_IMMEDIATE);
 }
@@ -217,6 +264,6 @@ int tf_yield(void)
 	struct tf_fiber *f = sched->active_fiber;
 
 	tf_list_add_tail(&f->queue_node, &sched->run_q);
-	return tf_schedule(TF_NO_TIMEOUT);
+	return tf_schedule();
 }
 
diff --git a/src/io-unix.c b/src/io-unix.c
index 8ed8e42..ea65a76 100644
--- a/src/io-unix.c
+++ b/src/io-unix.c
@@ -90,8 +90,7 @@ int tf_close(struct tf_fd *fd)
 	return 0;
 }
 
-int tf_read_fully(struct tf_fd *fd, void *buf, size_t count,
-		  tf_mtime_diff_t timeout)
+int tf_read_fully(struct tf_fd *fd, void *buf, size_t count)
 {
 	ssize_t n;
 	int r;
@@ -120,16 +119,14 @@ int tf_read_fully(struct tf_fd *fd, void *buf, size_t count,
 				continue;
 		}
 
-		r = tf_schedule(timeout);
-		timeout = TF_NO_TIMEOUT_CHANGE;
+		r = tf_schedule();
 	} while (r == TF_WAKEUP_FD);
 	tf_fd_unmonitor(fd);
 
 	return -r;
 }
 
-int tf_write_fully(struct tf_fd *fd, const void *buf, size_t count,
-		   tf_mtime_diff_t timeout)
+int tf_write_fully(struct tf_fd *fd, const void *buf, size_t count)
 {
 	ssize_t n;
 	int r;
@@ -155,15 +152,14 @@ int tf_write_fully(struct tf_fd *fd, const void *buf, size_t count,
 				continue;
 		}
 
-		r = tf_schedule(timeout);
-		timeout = TF_NO_TIMEOUT_CHANGE;
+		r = tf_schedule();
 	} while (r == TF_WAKEUP_FD);
 	tf_fd_unmonitor(fd);
 
 	return -r;
 }
 
-ssize_t tf_read(struct tf_fd *fd, void *buf, size_t count, tf_mtime_diff_t timeout)
+ssize_t tf_read(struct tf_fd *fd, void *buf, size_t count)
 {
 	ssize_t n;
 
@@ -178,16 +174,14 @@ ssize_t tf_read(struct tf_fd *fd, void *buf, size_t count, tf_mtime_diff_t timeo
 			n = -errno;
 			break;
 		}
-		n = tf_schedule(timeout);
-		timeout = TF_NO_TIMEOUT_CHANGE;
+		n = tf_schedule();
 	} while (n == TF_WAKEUP_FD);
 	tf_fd_unmonitor(fd);
 
 	return n;
 }
 
-ssize_t tf_write(struct tf_fd *fd, const void *buf, size_t count,
-		 tf_mtime_diff_t timeout)
+ssize_t tf_write(struct tf_fd *fd, const void *buf, size_t count)
 {
 	ssize_t n;
 
@@ -202,8 +196,7 @@ ssize_t tf_write(struct tf_fd *fd, const void *buf, size_t count,
 			n = -errno;
 			break;
 		}
-		n = tf_schedule(timeout);
-		timeout = TF_NO_TIMEOUT_CHANGE;
+		n = tf_schedule();
 	} while (n == TF_WAKEUP_FD);
 	tf_fd_unmonitor(fd);
 
@@ -250,7 +243,7 @@ int tf_listen(struct tf_fd *fd, int backlog)
 }
 
 int tf_accept(struct tf_fd *listen_fd, struct tf_fd *child_fd,
-	      struct tf_sockaddr *from, tf_mtime_diff_t timeout)
+	      struct tf_sockaddr *from)
 {
 	int r, tfdf;
 	struct sockaddr *addr = NULL;
@@ -277,8 +270,7 @@ int tf_accept(struct tf_fd *listen_fd, struct tf_fd *child_fd,
 			tf_fd_unmonitor(listen_fd);
 			return -errno;
 		}
-		r = tf_schedule(timeout);
-		timeout = TF_NO_TIMEOUT_CHANGE;
+		r = tf_schedule();
 	} while (r == TF_WAKEUP_FD);
 	tf_fd_unmonitor(listen_fd);
 	if (r < 0)
@@ -287,8 +279,7 @@ int tf_accept(struct tf_fd *listen_fd, struct tf_fd *child_fd,
 	return tf_open_fd(child_fd, r, tfdf);
 }
 
-int tf_connect(struct tf_fd *fd, const struct tf_sockaddr *to,
-	       tf_mtime_diff_t timeout)
+int tf_connect(struct tf_fd *fd, const struct tf_sockaddr *to)
 {
 	socklen_t l = sizeof(int);
 	int r, err;
@@ -302,7 +293,7 @@ int tf_connect(struct tf_fd *fd, const struct tf_sockaddr *to,
 
 	/* Wait for socket to become readable */
 	tf_fd_monitor(fd, EPOLLOUT);
-	r = tf_schedule(timeout);
+	r = tf_schedule();
 	tf_fd_unmonitor(fd);
 	if (r != TF_WAKEUP_FD)
 		return r;
@@ -316,8 +307,7 @@ int tf_connect(struct tf_fd *fd, const struct tf_sockaddr *to,
 ssize_t tf_recvmsg(struct tf_fd *fd,
 		   struct tf_sockaddr *from,
 		   struct tf_sockaddr *to,
-		   void *buf, size_t len,
-		   tf_mtime_diff_t timeout)
+		   void *buf, size_t len)
 {
 	struct iovec iov;
 	struct msghdr msg;
@@ -347,8 +337,7 @@ ssize_t tf_recvmsg(struct tf_fd *fd,
 			r = -errno;
 			break;
 		}
-		r = tf_schedule(timeout);
-		timeout = TF_NO_TIMEOUT_CHANGE;
+		r = tf_schedule();
 	} while (r == TF_WAKEUP_FD);
 	tf_fd_unmonitor(fd);
 
@@ -372,8 +361,7 @@ ssize_t tf_recvmsg(struct tf_fd *fd,
 ssize_t tf_sendmsg(struct tf_fd *fd,
 		   struct tf_sockaddr *from,
 		   const struct tf_sockaddr *to,
-		   const void *buf, size_t len,
-		   tf_mtime_diff_t timeout)
+		   const void *buf, size_t len)
 {
 	struct msghdr msg;
 	struct iovec iov;
@@ -412,8 +400,7 @@ ssize_t tf_sendmsg(struct tf_fd *fd,
 			r = -errno;
 			break;
 		}
-		r = tf_schedule(timeout);
-		timeout = TF_NO_TIMEOUT_CHANGE;
+		r = tf_schedule();
 	} while (r == TF_WAKEUP_FD);
 	tf_fd_unmonitor(fd);