Re: [RFA] Fix off-by-one error in record.c (record_list_release_first)

[Michael Snyder <msnyder at vmware dot com>]

Hui Zhu wrote:
> Thanks Michael and Jilin,
>
> I think the Michael's patch is more spend up.  Jilin's patch is more
> clear and can handle set_record_insn_max_num.
>
> I suggest we choice speed up.  Do you think it's OK?
>
> If we choice it, Michael, could you please add some comments to
> "record_list_release_first" or change it's name to
> "record_list_release_first_without_update_xxx" to make it clear.
> And please update set_record_insn_max_num.

Hah, sorry, I completely missed the implications for 
set_record_insn_max_num.  Thanks Jilin for catching it.

New diff:

2009-10-12  Michael Snyder  <msnyder@vmware.com>

	* record.c (record_list_release_first): Do not decrement
	record_insn_num.
	(set_insn_num_max): Remove printf.
	Decrement record_insn_num in the loop.

Index: record.c
===================================================================
RCS file: /cvs/src/src/gdb/record.c,v
retrieving revision 1.20
diff -u -p -r1.20 record.c
--- record.c	27 Sep 2009 02:49:34 -0000	1.20
+++ record.c	13 Oct 2009 18:04:44 -0000
@@ -177,6 +177,11 @@ record_list_release_next (void)
     }
 }
 
+/* Delete the first instruction from the beginning of the log, to make
+   room for adding a new instruction at the end of the log.
+
+   Note -- this function does not modify record_insn_num.  */
+
 static void
 record_list_release_first (void)
 {
@@ -209,8 +214,6 @@ record_list_release_first (void)
       if (type == record_end)
 	break;
     }
-
-  record_insn_num--;
 }
 
 /* Add a struct record_entry to record_arch_list.  */
@@ -1260,12 +1263,12 @@ set_record_insn_max_num (char *args, int
 {
   if (record_insn_num > record_insn_max_num && record_insn_max_num)
     {
-      printf_unfiltered (_("Record instructions number is bigger than "
-		           "record instructions max number.  Auto delete "
-		           "the first ones?\n"));
-
+      /* Count down record_insn_num while releasing records from list.  */
       while (record_insn_num > record_insn_max_num)
-	record_list_release_first ();
+	{
+	  record_list_release_first ();
+	  record_insn_num--;
+	}
     }
 }