From: Mark Wielaard <mjw@redhat.com>
Date: Sun, 25 Dec 2011 19:56:53 +0000 (+0100)
Subject: Use function.call and function.return in all thread_indent() examples.
X-Git-Tag: release-1.7~59
X-Git-Url: https://sourceware.org/git/?a=commitdiff_plain;h=2e96e9163d84fe9772def0318216a6d6da1332a2;p=systemtap.git

Use function.call and function.return in all thread_indent() examples.

If the .call modifier isn't used the function probes will match both .call
and .inline, but .return doesn't match any inlined functions leading to
unbalanced thread_indent output.
---

diff --git a/doc/SystemTap_Beginners_Guide/en-US/Scripts.xml b/doc/SystemTap_Beginners_Guide/en-US/Scripts.xml
index 06e117e6b..682e60e82 100644
--- a/doc/SystemTap_Beginners_Guide/en-US/Scripts.xml
+++ b/doc/SystemTap_Beginners_Guide/en-US/Scripts.xml
@@ -955,7 +955,7 @@ hald(2360) open</screen>
 					 </para>
 
 <example id="thread_indent"><title>thread_indent.stp</title>
-<programlisting>probe kernel.function("*@net/socket.c")
+<programlisting>probe kernel.function("*@net/socket.c").call
 {
   printf ("%s -> %s\n", thread_indent(1), probefunc())
 }
diff --git a/doc/tutorial.tex b/doc/tutorial.tex
index e948ade1f..10654d75f 100644
--- a/doc/tutorial.tex
+++ b/doc/tutorial.tex
@@ -272,7 +272,7 @@ interrupt it with \verb+^C+ when you want the tracing to stop.
 \begin{boxedminipage}{4.5in}
 \begin{verbatim}
 # cat socket-trace.stp
-probe kernel.function("*@net/socket.c") {
+probe kernel.function("*@net/socket.c").call {
   printf ("%s -> %s\n", thread_indent(1), probefunc())
 }
 probe kernel.function("*@net/socket.c").return {
@@ -317,6 +317,16 @@ probe kernel.function("*@net/socket.c").return {
   probe handler as in Figure~\ref{fig:socket-trace}.  Print parameters
   using \verb+$$parms+ and \verb+$$return+.  Interpret the results.
 
+\item Change figure~\ref{fig:socket-trace} by removing the \verb+.call+
+  modifier from the first probe.  Note how function entry and function
+  return now don't match anymore.  This is because now the first probe
+  will match both normal function entry and inlined functions.  Try
+  putting the \verb+.call+ modifier back and add another probe just for
+  \verb+probe kernel.function("*@net/socket.c").return+
+  What \verb+printf+ statement can you come up with in the probe handler
+  to show the inlined function entries nicely in between the \verb+.call+
+  and \verb+.return+ thread indented output?
+
 \end{enumerate}
 
 \section{Analysis}
diff --git a/doc/tutorial/socket-trace.stp b/doc/tutorial/socket-trace.stp
index 53b69ecc6..a34a33a8c 100644
--- a/doc/tutorial/socket-trace.stp
+++ b/doc/tutorial/socket-trace.stp
@@ -1,4 +1,4 @@
-probe kernel.function("*@net/socket.c") {
+probe kernel.function("*@net/socket.c").call {
   printf ("%s -> %s\n", thread_indent(1), probefunc())
 }
 probe kernel.function("*@net/socket.c").return {