From e37fd72a0e4150e79e94d30d26d0d082778c847a Mon Sep 17 00:00:00 2001
From: Ben Pfaff <blp@cs.stanford.edu>
Date: Sat, 9 Oct 2004 18:01:37 +0000
Subject: [PATCH] Comments.
---
src/threads/thread.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/src/threads/thread.c b/src/threads/thread.c
index b0d5a91..ee83e0d 100644
--- a/src/threads/thread.c
+++ b/src/threads/thread.c
@@ -376,6 +376,10 @@ next_thread_to_run (void)
the first time a thread is scheduled it is called by
switch_entry() (see switch.S).
+ It's not safe to call printf() until the thread switch is
+ complete. In practice that means that printf()s should be
+ added at the end of the function.
+
After this function and its caller returns, the thread switch
is complete. */
void
@@ -407,7 +411,10 @@ schedule_tail (struct thread *prev)
/* Schedules a new process. At entry, interrupts must be off and
the running process's state must have been changed from
running to some other state. This function finds another
- thread to run and switches to it. */
+ thread to run and switches to it.
+
+ It's not safe to call printf() until schedule_tail() has
+ completed. */
static void
schedule (void)
{
--
2.30.2