From e3c000d00d2f441088498adc4579e0c28b3b3ac1 Mon Sep 17 00:00:00 2001
From: Martin Mares <mj@ucw.cz>
Date: Tue, 1 Mar 2011 14:07:51 +0100
Subject: [PATCH] Main: Add main_step()

---
 ucw/mainloop.c | 29 ++++++++++++++++++++++++-----
 ucw/mainloop.h | 12 ++++++++++--
 2 files changed, 34 insertions(+), 7 deletions(-)

diff --git a/ucw/mainloop.c b/ucw/mainloop.c
index 1d213c03..7eb8c8ac 100644
--- a/ucw/mainloop.c
+++ b/ucw/mainloop.c
@@ -787,10 +787,15 @@ main_loop(void)
 	  break;
 	default: ;
 	}
-      if (count_timers(m))
-	wake = MIN(wake, m->timer_table[1]->expires);
-      main_get_time_ctx(m);
-      int timeout = ((wake > m->now) ? wake - m->now : 0);
+
+      int timeout = 0;
+      if (!m->single_step)
+	{
+	  if (count_timers(m))
+	    wake = MIN(wake, m->timer_table[1]->expires);
+	  main_get_time_ctx(m);
+	  timeout = ((wake > m->now) ? wake - m->now : 0);
+	}
 
 #ifdef CONFIG_UCW_EPOLL
       recalc_files(m);
@@ -811,7 +816,12 @@ main_loop(void)
       m->idle_time += m->now - old_now;
 
       if (n <= 0)
-	continue;
+	{
+	  if (m->single_step)
+	    return;
+	  else
+	    continue;
+	}
 
       // Relink all files with a pending event to file_active_list
 #ifdef CONFIG_UCW_EPOLL
@@ -867,3 +877,12 @@ main_loop(void)
 	}
     }
 }
+
+void
+main_step(void)
+{
+  struct main_context *m = main_current();
+  m->single_step = 1;
+  main_loop();
+  m->single_step = 0;
+}
diff --git a/ucw/mainloop.h b/ucw/mainloop.h
index a1d4e24d..ae1c1e4a 100644
--- a/ucw/mainloop.h
+++ b/ucw/mainloop.h
@@ -24,10 +24,10 @@
 
 /** The main loop context **/
 struct main_context {
-  timestamp_t now;			/* [*] Current time in milliseconds since the UNIX epoch. See @main_get_time(). */
+  timestamp_t now;			/* [*] Current time in milliseconds since the UNIX epoch. See main_get_time(). */
   ucw_time_t now_seconds;		/* [*] Current time in seconds since the epoch. */
   timestamp_t idle_time;		/* [*] Total time in milliseconds spent by waiting for events. */
-  uns shutdown;				/* [*] Setting this to nonzero forces the @main_loop() function to terminate. */
+  uns shutdown;				/* [*] Setting this to nonzero forces the main_loop() function to terminate. */
   clist file_list;
   clist file_active_list;
   clist hook_list;
@@ -35,6 +35,7 @@ struct main_context {
   clist process_list;
   clist signal_list;
   uns file_cnt;
+  uns single_step;
 #ifdef CONFIG_UCW_EPOLL
   int epoll_fd;				/* File descriptor used for epoll */
   struct epoll_event *epoll_events;
@@ -95,6 +96,13 @@ void main_teardown(void);
  **/
 void main_loop(void);
 
+/**
+ * Perform a single iteration of the main loop.
+ * Check if there are any events ready and process them.
+ * If there are none, do not wait.
+ **/
+void main_step(void);
+
 /** Ask the main loop to terminate at the nearest occasion. **/
 static inline void main_shut_down(void)
 {
-- 
2.39.2